50mm f2 vs 35mm 1.4 - which has more bokeh?

Started 3 months ago | Discussions
saltydogstudios
saltydogstudios Senior Member • Posts: 2,173
Re: What I think about when I think about focal length.

rlx wrote:

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

@JNR. Very good insights. Thank's for sharing. Lenses look simple but each one brings it's own personality and each one has its specific uses. Right.

@saltydogstudio. I really enjoyed reading your write-up. It's very well done and very well balanced for people who like Photography. I think we share a common interest in Cartier-Bresson's using his legendary Elmar 50mm and the creative approach of Elena Shumilova with her Canon 85mm f/1.2. She definitely knows how to use light.

I thought she was mostly Nikon 135 f/2 - but maybe she just said that in an interview because they sent her a free lens. LOL.

I wonder what Cartier-Bresson would do with the Fuji 35mm f/1.4 (the infamous nifty-fifty equivalent, right?).

I think he'd prefer the smaller aperture version because "depth of field is an effect and should be avoided." (not an actual quote quote).

I think HCB would have appreciated the larger depth of field you could get on APS-C and m32 and would have been a fan of those formats and would have gone for the 50mm equivalent one each.

But I suspect he would have preferred the 3:2 aspect ratio for his work.

So my guess is HCB would have gone for a Fuji X-Pro with 35mm f/2 lens.

Interesting thought provoking question.

-- hide signature --
 saltydogstudios's gear list:saltydogstudios's gear list
Ricoh GR Digital Sigma DP2 Merrill Sigma DP3 Merrill Sigma dp3 Quattro Nikon D7000 +6 more
rlx
rlx Senior Member • Posts: 1,129
Re: What I think about when I think about focal length.

saltydogstudios wrote:

rlx wrote:

...

@saltydogstudio. I really enjoyed reading your write-up. It's very well done and very well balanced for people who like Photography. I think we share a common interest in Cartier-Bresson's using his legendary Elmar 50mm and the creative approach of Elena Shumilova with her Canon 85mm f/1.2. She definitely knows how to use light.

I thought she was mostly Nikon 135 f/2 - but maybe she just said that in an interview because they sent her a free lens. LOL.

I am quoting from memory (not always good). I know the article is saying Nikon 135.

I wonder what Cartier-Bresson would do with the Fuji 35mm f/1.4 (the infamous nifty-fifty equivalent, right?).

I think he'd prefer the smaller aperture version because "depth of field is an effect and should be avoided." (not an actual quote quote).

I think HCB would have appreciated the larger depth of field you could get on APS-C and m32 and would have been a fan of those formats and would have gone for the 50mm equivalent one each.

But I suspect he would have preferred the 3:2 aspect ratio for his work.

So my guess is HCB would have gone for a Fuji X-Pro with 35mm f/2 lens.

Interesting thought provoking question.

I like that answer. The only thing I could say in favor of the 1.4 is that focusing is quite accurate and quick with the xt3 even in tracking mode. I took the following picture on my first walk out with the 35 f/1.4 on wide tracking mode. HCB couldn't achieve such accurate focusing with his Leica and Elmar f/3.5. He needed some tolerance, some room for inaccuracies.

I had the 35 f/1.4 for a couple of days. I think I like the second one better even if it might create more distortion..

JNR
JNR Veteran Member • Posts: 4,019
Re: What I think about when I think about focal length.

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

While you clearly understand, how your words express that understanding cause confusion and possible misunderstanding. Where you stand in relation to the subject is perspective. It isn't related to distortion as you are referencing it. If you move forward or backward the translation of the 3D perspective into the 2D mapping will necessarily change those 3D relationships in some form of perceived distortion.

When you interject a photographer's rudimentary understanding of "distortion" which is generally the unfortunate blind acceptance of "rectilinear perspective" - that is nonetheless a type of distortion - often extreme depending on FoV.

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

We can get into this much further if you wish because I have studied it deeply, but your confusion of the notions of "perspective" and "distortion" as most photographers understand it is a red herring - at least in how you express it in the above post.

-- hide signature --

JNR

 JNR's gear list:JNR's gear list
Fujifilm X-T2 Fujifilm 50mm F2 R WR Phase One Capture One Pro Pentax K-01 Pentax K-3 +21 more
Greg7579
Greg7579 Forum Pro • Posts: 10,808
Re: 50mm f2 vs 35mm 1.4 - which has more bokeh?

rlx wrote:

I need to add the fact the MF sensor gathers two stops more light than the APSC sensor so the ISO can be jacked 2 stops on MF and the aperture reduced by the same so the end result is that both cameras will take pictures of the same DOF.

rlx,

You kinda got that all messed up.  I think I know what you are trying to say, but aperture equivalence is immensely more complicated than that and the way you talked about  light gathering and ISO is a bit of a mess.

If you are comparing Fuji X to GFX in terms of aperture equivalence, sensor size, DOF, DR, crop factors, light gathering, diffraction, or light gathering (as you called it), it is a little more complicated than that.

But I think I know what you are trying to say.  No worries.

I shoot both systems and the biggest thing I notice between X and GFX is just the pure resolution that with GFX just blows your mind, greatly increased latitude in post / increased DR with GFX and the fact that I have far less DOF (in general) in normal shooting situations with GFX compared to X.

-- hide signature --
 Greg7579's gear list:Greg7579's gear list
Leica Q2 Fujifilm GFX 50R Fujifilm GFX 100 Fujifilm GF 32-64mm F4 Fujifilm 120mm F4 Macro +6 more
saltydogstudios
saltydogstudios Senior Member • Posts: 2,173
Re: What I think about when I think about focal length.
1

JNR wrote:

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

While you clearly understand, how your words express that understanding cause confusion and possible misunderstanding. Where you stand in relation to the subject is perspective. It isn't related to distortion as you are referencing it. If you move forward or backward the translation of the 3D perspective into the 2D mapping will necessarily change those 3D relationships in some form of perceived distortion.

When you interject a photographer's rudimentary understanding of "distortion" which is generally the unfortunate blind acceptance of "rectilinear perspective" - that is nonetheless a type of distortion - often extreme depending on FoV.

In the article I talk about the difference between "perspective distortion" and lens distortions.

Based on your response, I'm not sure if you've read the article or not.

As far as rectilinear perspective - perhaps it has the impact that you say, though I hardly imagine that it's an issue at 43mm. If I'm looking through a viewfinder with my right eye that's 1:1 (such as on the Epson R-D1) with a 43mm field of view and can keep my left eye open and see the same perspective on the world - I don't imagine that rectilinear perspective would be a type of "distortion" at that focal length.

Wider focal lengths? Yes. But I'm specifically talking about 43mm - in response to your talking about 35 to 40mm, which is a bit wider and may be subject to some rectilinear distortion as you say, but i was specifically talking about 43mm.

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

I talk about that specific issue in this article (linked from the other one) in depth.

https://medium.com/ice-cream-geometry/what-is-a-normal-lens-35mm-50mm-43mm-compared-to-the-human-eye-cf7e43cc3366

We can get into this much further if you wish because I have studied it deeply, but your confusion of the notions of "perspective" and "distortion" as most photographers understand it is a red herring - at least in how you express it in the above post.

So - "perspective distortion" is not a type of distortion?

https://en.wikipedia.org/wiki/Perspective_distortion_(photography)

You may want to update the Wikipedia article then.

Again - I can't tell from your response if you read the article I posted or not where I talk about how perspective distortion is distinct from lens distortions. If you have a specific correction I'm open to hearing it - if your post is a specific correction - then perhaps I just didn't understand what specifically you were correcting.

-- hide signature --
 saltydogstudios's gear list:saltydogstudios's gear list
Ricoh GR Digital Sigma DP2 Merrill Sigma DP3 Merrill Sigma dp3 Quattro Nikon D7000 +6 more
saltydogstudios
saltydogstudios Senior Member • Posts: 2,173
Re: What I think about when I think about focal length.
1

rlx wrote:

saltydogstudios wrote:

rlx wrote:

...

@saltydogstudio. I really enjoyed reading your write-up. It's very well done and very well balanced for people who like Photography. I think we share a common interest in Cartier-Bresson's using his legendary Elmar 50mm and the creative approach of Elena Shumilova with her Canon 85mm f/1.2. She definitely knows how to use light.

I thought she was mostly Nikon 135 f/2 - but maybe she just said that in an interview because they sent her a free lens. LOL.

I am quoting from memory (not always good). I know the article is saying Nikon 135.

I wonder what Cartier-Bresson would do with the Fuji 35mm f/1.4 (the infamous nifty-fifty equivalent, right?).

I think he'd prefer the smaller aperture version because "depth of field is an effect and should be avoided." (not an actual quote quote).

I think HCB would have appreciated the larger depth of field you could get on APS-C and m32 and would have been a fan of those formats and would have gone for the 50mm equivalent one each.

But I suspect he would have preferred the 3:2 aspect ratio for his work.

So my guess is HCB would have gone for a Fuji X-Pro with 35mm f/2 lens.

Interesting thought provoking question.

I like that answer. The only thing I could say in favor of the 1.4 is that focusing is quite accurate and quick with the xt3 even in tracking mode. I took the following picture on my first walk out with the 35 f/1.4 on wide tracking mode. HCB couldn't achieve such accurate focusing with his Leica and Elmar f/3.5. He needed some tolerance, some room for inaccuracies.

I'm sure he preferred a larger depth of field as well. Or perhaps rangefinder focusing allowed him to focus to the depth he intuited by feel without having to use his eyes to focus.

This was a fun video on the man.

https://www.youtube.com/watch?v=fRtV1MZph_4

His technique of holding the camera and then moving it to his eyes only momentarily to focus the camera allowed him to get closer to the action without being noticed. The fluid movements suggested in the video, to me, say that the camera was already focused to the right distance before it arrived at his eye.

I had the 35 f/1.4 for a couple of days. I think I like the second one better even if it might create more distortion..

-- hide signature --
 saltydogstudios's gear list:saltydogstudios's gear list
Ricoh GR Digital Sigma DP2 Merrill Sigma DP3 Merrill Sigma dp3 Quattro Nikon D7000 +6 more
KariP
KariP Veteran Member • Posts: 5,529
Re: Is "bokeh" necessary for portraits ?
1

Truman Prevatt wrote:

KariP wrote:

Spazmaster wrote:

Im working on filling in my prime lineup, currently have 18f2, 23 f2, 27 2.8, 35 1.4

Was thinking about adding in a 50mm f2 to round it out and have something for portraits. Im wondering if anyone has input on how much bokeh I would get with the 35 f1.4 at f1.4 vs 50f2 at f2

Would you guys grab this lens or go for something longer like the Viltrox 85 or Fuji f2?

Very often I see people buying or planning to buy some lens for portraits because it has very shallow DOF and "speed" ( 56mmf 1,2 or something)

Nice bokeh looks good , sometimes. I have been looking at some portraits - especially from old masters and of course some modern . Extremely shallow DOF is actually used very seldom - if ever. Some photographers also use the surroundings/landscape or persons home so that it is not blurred away and also tells something of the persons personality. Perhaps also some statue or art can benefit from very shallow DOF - anyway a lot of background blur is not a measure of quality - of the lens or the photographer.

A lot of old masters did not have fast lenses. Shallow DOF is but a tool and it is often a tool that is the difference between getting a shot and not getting a shot. Putting a person in his environment can provide more interest but if there is a toaster and water faucet with specular reflections in the background - the eye is drawn to the toaster and faucet not the subject and hence they are distractions. The solution is narrow DOF and melt the distractions away in a smooth bokeh.

This shot taken with the XPro2 and 56 f1.2 at 1.2 would not have been possible without narrow DOF because of the shiny objects in the background that were sunlit from a window. The bokeh of this eliminated the distraction.

One doesn't need the tattoos in sharp focus to know that Dan here is a die hard Marine Expo vet.

For outdoor portraits pine and fur trees make a wonderful back ground and open overcast sky lighting is the most flattering. But again the pine needles don't need to be in focus to give a feel for the environment. If they were - the eye might be drawn to the needles instead of the subject.

Taken on TriX using a Mamiya RB67 with a 127 f4 lens at f4

DOF is a tool that comes in very handy to focus the viewers eye to the subject and mitigate distractions in the frame. If used correctly - it is one of the more powerful tools at the photographers disposal. Can it be over used? Anything can be over used. The reason I prefer fast lenses is they give me options. With a slow lens I don't have the option to isolate a subject and control background distractions and in many cases the only option is just to walk away from a shot.

Dorothea Lange was a master in the creative use of DOF to give the viewer just enough to get a feel from the environment while focusing the viewers eye like a laser to the main subject.

https://www.artsy.net/article/artsy-editorial-dorothea-langes-5-iconic-images

I understand perfectly, that shallow DOF CAN sometimes be very useful. It is not an absolute  necessity IMO.  Portrait photography does not start from getting a f1,2 lens. If someone wants to try portrait photography it is more important to think how the focal length /distance works. Long enough focal length makes the perspective more like natural - and then f 2,8 or 4 gives enough of DOF  (With a 85mm lens) .

Portraits are difficult and really good portraits are rare.  The best ones I have seen are not taken with f 1,2. They were taken by photographers who understand the personality of their model...  f2,8 ... f 11 ,  right light and psychology is more useful that f1,2  

f1,2 is a style decision - useful if you know what you are doing.   In reportages/ street  and such it can look great ,  separating the background.  I mean that serious portraits of some person should be taken with time and serious pre meditation/thinking . Not just fast grabs.

-- hide signature --

Kari
I started SLR film photography in 1968, first DSLR was Canon 40D in 2007. Now Fujifilm X-E3 and X-H1 for nature, walking around ,traveling/landscapes - fantastic 5DMkIV for landscapes, macro , BIF ... .

 KariP's gear list:KariP's gear list
Canon EOS 5D Mark IV Fujifilm X-E3 Canon EF 50mm F1.4 USM Canon EF 24-105mm f/4L IS USM Fujifilm XF 18-55mm F2.8-4 R LM OIS +10 more
KariP
KariP Veteran Member • Posts: 5,529
Re: Is "bokeh" necessary for portraits ?
1

William Loney wrote:

KariP wrote:

Spazmaster wrote:

Im working on filling in my prime lineup, currently have 18f2, 23 f2, 27 2.8, 35 1.4

Was thinking about adding in a 50mm f2 to round it out and have something for portraits. Im wondering if anyone has input on how much bokeh I would get with the 35 f1.4 at f1.4 vs 50f2 at f2

Would you guys grab this lens or go for something longer like the Viltrox 85 or Fuji f2?

Very often I see people buying or planning to buy some lens for portraits because it has very shallow DOF and "speed" ( 56mmf 1,2 or something)

Nice bokeh looks good , sometimes. I have been looking at some portraits - especially from old masters and of course some modern . Extremely shallow DOF is actually used very seldom - if ever. Some photographers also use the surroundings/landscape or persons home so that it is not blurred away and also tells something of the persons personality. Perhaps also some statue or art can benefit from very shallow DOF - anyway a lot of background blur is not a measure of quality - of the lens or the photographer.

Thank you! This needed to be said.

We are in the era of the 'bokeh fad,' much like the era of the HDR fad of some years ago, the saturated colour fad of the early '90s, the starburst filter fad of the 'late '70s......

It will pass, but I wonder how many will look at older portraits in the future and wish that they could 'un-bokeh' all those portraits that they are taking today.

Much as I love my 56, I wouldn't dare present a client with a set of shots all taken wide open @f1.2. Don't think they'd really appreciate my 'artistic interpretations!'

I did a series of headshots the other day, with the bulk being at f5.6. A few 3/4 shots at f4, and that's it.

Happy client, happy photographer.

Those wider apertures? Full body portraits from the appropriate distances look great, as do other situations where light is scarce.

Thanks

I'm not a professional at all. I have a couple of times taken some portraits of a couple after/before wedding and they have been quite happy - and even I have liked the results. It is really difficult! They still have the photographs hanging on a wall or framed.  Also still married - not sure if the portraits have helped , I hope so

I had f 1,2 and f 1,4 lenses then , but did not use them  very much ...  best result I got with  a zoom 24-105 f 4  (using f5,6-7) on a FF camera.  X-T1 was used with 18-55...

Does not sound like a professional - I'm an amateur anyway  no reputation to protect 

-- hide signature --

Kari
I started SLR film photography in 1968, first DSLR was Canon 40D in 2007. Now Fujifilm X-E3 and X-H1 for nature, walking around ,traveling/landscapes - fantastic 5DMkIV for landscapes, macro , BIF ... .

 KariP's gear list:KariP's gear list
Canon EOS 5D Mark IV Fujifilm X-E3 Canon EF 50mm F1.4 USM Canon EF 24-105mm f/4L IS USM Fujifilm XF 18-55mm F2.8-4 R LM OIS +10 more
rlx
rlx Senior Member • Posts: 1,129
Re: 50mm f2 vs 35mm 1.4 - which has more bokeh?

Greg7579 wrote:

rlx wrote:

I need to add the fact the MF sensor gathers two stops more light than the APSC sensor so the ISO can be jacked 2 stops on MF and the aperture reduced by the same so the end result is that both cameras will take pictures of the same DOF.

rlx,

You kinda got that all messed up. I think I know what you are trying to say, but aperture equivalence is immensely more complicated than that and the way you talked about light gathering and ISO is a bit of a mess.

If you are comparing Fuji X to GFX in terms of aperture equivalence, sensor size, DOF, DR, crop factors, light gathering, diffraction, or light gathering (as you called it), it is a little more complicated than that.

But I think I know what you are trying to say. No worries.

I shoot both systems and the biggest thing I notice between X and GFX is just the pure resolution that with GFX just blows your mind, greatly increased latitude in post / increased DR with GFX and the fact that I have far less DOF (in general) in normal shooting situations with GFX compared to X.

Greg. You remind me of my father who often said things were more complicated than they looked while I generally tried to look at things in as simple terms as is possible or practical . A great man of Physics who is often over-quoted said something like that -- The world is as simple and as complicated as it is. I would say that there is no need to make things more complicated than they are if one can account for all the facts -- and if one can't be proved to be wrong.

I am sure that shooting MF is very a gratifying experience when looking at the results in 4K. I hope I didn't say anything that an MF photographer could take offense of . The OP is looking for shallow DOF and you are in the right shoes to tell him it's time for him to move from Fuji-X to MF .

rlx
rlx Senior Member • Posts: 1,129
Re: What I think about when I think about focal length.

saltydogstudios wrote:

...

I'm sure he preferred a larger depth of field as well. Or perhaps rangefinder focusing allowed him to focus to the depth he intuited by feel without having to use his eyes to focus.

This was a fun video on the man.

https://www.youtube.com/watch?v=fRtV1MZph_4

His technique of holding the camera and then moving it to his eyes only momentarily to focus the camera allowed him to get closer to the action without being noticed. The fluid movements suggested in the video, to me, say that the camera was already focused to the right distance before it arrived at his eye

I am grateful you provided that link. I like the pictures of course and more specifically I enjoyed the description of his stealthy shooting technique .

That gives me home ideas, some software shooting tools for the camera. It's too bad there is no CHDK toolkit on Fuji so anyone could add to the existing software .

I also viewed a few videos on HCB where he speaks French. He says that he uses his training in painting and drawing, he is all intuitive, very fast "fast, fast, fast", very mobile and alert. He is documenting life, not as a voyeur but with the sense of a mission. The camera is a tool and a weapon, a defensive weapon to help people. He loves both portrait and showing the interactions in groups of people. He says portrait is a form of aggression, an intrusion in privacy and he lives with that.

Don't forget the early Leica's had a very short 50ms shutter lag. My XE1 had a 250ms shutter lag in AF-M mode with a legacy lens in 2013. I measured it. Fuji later corrected that flaw and the Fuji shutter lag is now close to the old Leica's.

I think I will be looking for a good legacy 35mm for my Fuji camera!

Truman Prevatt
Truman Prevatt Forum Pro • Posts: 11,062
Re: What I think about when I think about focal length.
1

JNR wrote:

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

While you clearly understand, how your words express that understanding cause confusion and possible misunderstanding. Where you stand in relation to the subject is perspective. It isn't related to distortion as you are referencing it. If you move forward or backward the translation of the 3D perspective into the 2D mapping will necessarily change those 3D relationships in some form of perceived distortion.

When you interject a photographer's rudimentary understanding of "distortion" which is generally the unfortunate blind acceptance of "rectilinear perspective" - that is nonetheless a type of distortion - often extreme depending on FoV.

Euclidean geometry is not the proper tool for describing photography. All light on a ray are focused on the same point on a sensor. Only one plane is in focus. Looking at an image it is impossible to determine size difference because that depends on the relationships between the locations of the objects relative to the camera.

For vision, projective geometry is the appropriate geometry because the camera projects all light on a given ray onto the same point. Length and distance is not preserved in projective geometry as it is in Euclidean geometry. Look at the first image in this

https://courses.engr.illinois.edu/cs543/sp2012/lectures/Lecture%2011%20-%20Projective%20Geometry%20and%20Camera%20Models%20-%20Vision_Spring2012.pdf

We have stereo vision because we have two eyes. The camera only has one and hence the images we see coming from our camera are as if we viewed the world with one eye

https://people.southwestern.edu/~futamurf/Day1_2_introtalk.pdf

Projective geometry is the foundation of computer vision.

There is no way to determine height. One would need a second image from a different perspective and knowledge of locations to do that (stereo imaging). The techniques of computer vision are based on projective geometry not Euclidean geometry. The size relations between objects are determined by the lateral magnification and axial magnification of the lens and are a function of the focal length. The greater the focal length the greater the magnification. It is the magnification - in particular the axial magnification that introduces the near to far distortion seen in lenses from the big nose small ear wide angle effect to the flatten telephoto effect. Below is the same scene and in the frame the girl is the same size relative to the frame but look at the bridge.

https://photography.tutsplus.com/tutorials/exploring-how-focal-length-affects-images--photo-6508

The size of the bridge relation to the woman appears larger in the telephoto that the wide angle although in reality no size changes.

Once we accept that the Euclidean geometry is not the appropriate description of the projection of three dimensions onto a plane, then a lot of concepts in photography and visual arts in general become much more clear. What some call distortion (lateral distortion in the image) arises because projective geometry does not preserve distance as Euclidean geometry does. The front to back compression distortion is because of the difference in axial magnification in an image and is a function of focal length solely.

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

The eye is very complex. It is only in a narrow field of view that our vision is high resolution. Moving away from the visual axis the resolution of the eye decreases. Our preferential vision is really only an indicator so we won't be surprised and turn out heads and/or eyes to focus. Probably evolutionary to keep humans from being eaten. The decrease of resolution as a function of angle from the optical axis is not fixed, is a continuum and varies with individuals. That is the reason most likely different people prefer different "normal" lenses ranging from between 35 to 65 to maybe even 75 mm (FF equiv).

-- hide signature --

_____
"The winds of heaven is that which blows between a horse's ears," Arabic Proverb
__
Truman
www.pbase.com/tprevatt

 Truman Prevatt's gear list:Truman Prevatt's gear list
Fujifilm X-H1 Fujifilm X-Pro3 Fujifilm XF 18mm F2 R Fujifilm XF 35mm F1.4 R Fujifilm XF 55-200mm F3.5-4.8 R LM OIS +10 more
KariP
KariP Veteran Member • Posts: 5,529
A portrait

KariP wrote:

William Loney wrote:

KariP wrote:

Spazmaster wrote:

Im working on filling in my prime lineup, currently have 18f2, 23 f2, 27 2.8, 35 1.4

Was thinking about adding in a 50mm f2 to round it out and have something for portraits. Im wondering if anyone has input on how much bokeh I would get with the 35 f1.4 at f1.4 vs 50f2 at f2

Would you guys grab this lens or go for something longer like the Viltrox 85 or Fuji f2?

Very often I see people buying or planning to buy some lens for portraits because it has very shallow DOF and "speed" ( 56mmf 1,2 or something)

Nice bokeh looks good , sometimes. I have been looking at some portraits - especially from old masters and of course some modern . Extremely shallow DOF is actually used very seldom - if ever. Some photographers also use the surroundings/landscape or persons home so that it is not blurred away and also tells something of the persons personality. Perhaps also some statue or art can benefit from very shallow DOF - anyway a lot of background blur is not a measure of quality - of the lens or the photographer.

Thank you! This needed to be said.

We are in the era of the 'bokeh fad,' much like the era of the HDR fad of some years ago, the saturated colour fad of the early '90s, the starburst filter fad of the 'late '70s......

It will pass, but I wonder how many will look at older portraits in the future and wish that they could 'un-bokeh' all those portraits that they are taking today.

Much as I love my 56, I wouldn't dare present a client with a set of shots all taken wide open @f1.2. Don't think they'd really appreciate my 'artistic interpretations!'

I did a series of headshots the other day, with the bulk being at f5.6. A few 3/4 shots at f4, and that's it.

Happy client, happy photographer.

Those wider apertures? Full body portraits from the appropriate distances look great, as do other situations where light is scarce.

Thanks

I'm not a professional at all. I have a couple of times taken some portraits of a couple after/before wedding and they have been quite happy - and even I have liked the results. It is really difficult! They still have the photographs hanging on a wall or framed. Also still married - not sure if the portraits have helped , I hope so

I had f 1,2 and f 1,4 lenses then , but did not use them very much ... best result I got with a zoom 24-105 f 4 (using f5,6-7) on a FF camera. X-T1 was used with 18-55...

Does not sound like a professional - I'm an amateur anyway no reputation to protect

English is my 3rd language - I had to check if I have understood what a portrait is/means:

portrait | noun

a painting, drawing, photograph, or engraving of a person, especially one depicting only the face or head and shoulders: a portrait of George III | [as modifier] : a portrait painter. •

a representation or impression of someone or something in language or on film or television: the writer builds up a fascinating portrait of a community.

Of course f 1,2 is OK  if you have such lens - but there are other aspects in portraiture

-- hide signature --

Kari
I started SLR film photography in 1968, first DSLR was Canon 40D in 2007. Now Fujifilm X-E3 and X-H1 for nature, walking around ,traveling/landscapes - fantastic 5DMkIV for landscapes, macro , BIF ... .

 KariP's gear list:KariP's gear list
Canon EOS 5D Mark IV Fujifilm X-E3 Canon EF 50mm F1.4 USM Canon EF 24-105mm f/4L IS USM Fujifilm XF 18-55mm F2.8-4 R LM OIS +10 more
Greg7579
Greg7579 Forum Pro • Posts: 10,808
Re: What I think about when I think about focal length.

Truman Prevatt wrote:

JNR wrote:

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

While you clearly understand, how your words express that understanding cause confusion and possible misunderstanding. Where you stand in relation to the subject is perspective. It isn't related to distortion as you are referencing it. If you move forward or backward the translation of the 3D perspective into the 2D mapping will necessarily change those 3D relationships in some form of perceived distortion.

When you interject a photographer's rudimentary understanding of "distortion" which is generally the unfortunate blind acceptance of "rectilinear perspective" - that is nonetheless a type of distortion - often extreme depending on FoV.

Euclidean geometry is not the proper tool for describing photography. All light on a ray are focused on the same point on a sensor. Only one plane is in focus. Looking at an image it is impossible to determine size difference because that depends on the relationships between the locations of the objects relative to the camera.

For vision, projective geometry is the appropriate geometry because the camera projects all light on a given ray onto the same point. Length and distance is not preserved in projective geometry as it is in Euclidean geometry. Look at the first image in this

https://courses.engr.illinois.edu/cs543/sp2012/lectures/Lecture%2011%20-%20Projective%20Geometry%20and%20Camera%20Models%20-%20Vision_Spring2012.pdf

We have stereo vision because we have two eyes. The camera only has one and hence the images we see coming from our camera are as if we viewed the world with one eye

https://people.southwestern.edu/~futamurf/Day1_2_introtalk.pdf

Projective geometry is the foundation of computer vision.

There is no way to determine height. One would need a second image from a different perspective and knowledge of locations to do that (stereo imaging). The techniques of computer vision are based on projective geometry not Euclidean geometry. The size relations between objects are determined by the lateral magnification and axial magnification of the lens and are a function of the focal length. The greater the focal length the greater the magnification. It is the magnification - in particular the axial magnification that introduces the near to far distortion seen in lenses from the big nose small ear wide angle effect to the flatten telephoto effect. Below is the same scene and in the frame the girl is the same size relative to the frame but look at the bridge.

https://photography.tutsplus.com/tutorials/exploring-how-focal-length-affects-images--photo-6508

The size of the bridge relation to the woman appears larger in the telephoto that the wide angle although in reality no size changes.

Once we accept that the Euclidean geometry is not the appropriate description of the projection of three dimensions onto a plane, then a lot of concepts in photography and visual arts in general become much more clear. What some call distortion (lateral distortion in the image) arises because projective geometry does not preserve distance as Euclidean geometry does. The front to back compression distortion is because of the difference in axial magnification in an image and is a function of focal length solely.

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

The eye is very complex. It is only in a narrow field of view that our vision is high resolution. Moving away from the visual axis the resolution of the eye decreases. Our preferential vision is really only an indicator so we won't be surprised and turn out heads and/or eyes to focus. Probably evolutionary to keep humans from being eaten. The decrease of resolution as a function of angle from the optical axis is not fixed, is a continuum and varies with individuals. That is the reason most likely different people prefer different "normal" lenses ranging from between 35 to 65 to maybe even 75 mm (FF equiv).

My left eyeball just exploded reading this thread....

-- hide signature --
 Greg7579's gear list:Greg7579's gear list
Leica Q2 Fujifilm GFX 50R Fujifilm GFX 100 Fujifilm GF 32-64mm F4 Fujifilm 120mm F4 Macro +6 more
saltydogstudios
saltydogstudios Senior Member • Posts: 2,173
Re: What I think about when I think about focal length.

Truman Prevatt wrote:

JNR wrote:

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

While you clearly understand, how your words express that understanding cause confusion and possible misunderstanding. Where you stand in relation to the subject is perspective. It isn't related to distortion as you are referencing it. If you move forward or backward the translation of the 3D perspective into the 2D mapping will necessarily change those 3D relationships in some form of perceived distortion.

When you interject a photographer's rudimentary understanding of "distortion" which is generally the unfortunate blind acceptance of "rectilinear perspective" - that is nonetheless a type of distortion - often extreme depending on FoV.

Euclidean geometry is not the proper tool for describing photography. All light on a ray are focused on the same point on a sensor. Only one plane is in focus. Looking at an image it is impossible to determine size difference because that depends on the relationships between the locations of the objects relative to the camera.

An exercise I do that's really helped train myself is, when looking at a photo, I ask "where was the camera?"

Imagine myself in the scene taking the photo - where was the camera? What lens was used? etc.

There are often enough context clues to come to some guess about the focal length used and the location of the camera.

For vision, projective geometry is the appropriate geometry because the camera projects all light on a given ray onto the same point. Length and distance is not preserved in projective geometry as it is in Euclidean geometry. Look at the first image in this

https://courses.engr.illinois.edu/cs543/sp2012/lectures/Lecture%2011%20-%20Projective%20Geometry%20and%20Camera%20Models%20-%20Vision_Spring2012.pdf

That's a great presentation.

The infamous McCain "grab" photo is an example of extreme perspective compression.

In reality he was nowhere near Obama and this was just a random moment, but the perspective compression makes it seem like he's gesturing at Obama.

The same with this photo of Obama "checking out" a woman.

Political photos are useful illustrations for perspective compression because they're often taken from so far away. Also sports/action/wildlife.

We have stereo vision because we have two eyes. The camera only has one and hence the images we see coming from our camera are as if we viewed the world with one eye

https://people.southwestern.edu/~futamurf/Day1_2_introtalk.pdf

Projective geometry is the foundation of computer vision.

Taking a drawing class can also be helpful in training you how to "see" the world.

We're so used to the way our eyes see the world that we have to learn to mentally separate and visualize how a camera is different from the eye.

Everything from white balance to perspective geometry to dynamic range. I think a lot of photographers try to perfect all of these things to produce images with the fewest "distortions" - I prefer to exploit how cameras are different from the eye in my work.

("distortions" in air quotes)

There is no way to determine height. One would need a second image from a different perspective and knowledge of locations to do that (stereo imaging). The techniques of computer vision are based on projective geometry not Euclidean geometry. The size relations between objects are determined by the lateral magnification and axial magnification of the lens and are a function of the focal length. The greater the focal length the greater the magnification. It is the magnification - in particular the axial magnification that introduces the near to far distortion seen in lenses from the big nose small ear wide angle effect to the flatten telephoto effect. Below is the same scene and in the frame the girl is the same size relative to the frame but look at the bridge.

https://photography.tutsplus.com/tutorials/exploring-how-focal-length-affects-images--photo-6508

The size of the bridge relation to the woman appears larger in the telephoto that the wide angle although in reality no size changes.

That's a great illustration of the kind of mental exercise I'm talking about - look at a photo, ask yourself "what is the focal length of the lens, where was the camera?"

Once we accept that the Euclidean geometry is not the appropriate description of the projection of three dimensions onto a plane, then a lot of concepts in photography and visual arts in general become much more clear. What some call distortion (lateral distortion in the image) arises because projective geometry does not preserve distance as Euclidean geometry does. The front to back compression distortion is because of the difference in axial magnification in an image and is a function of focal length solely.

I suppose telecentric lenses are an exception to this rule.

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

The eye is very complex. It is only in a narrow field of view that our vision is high resolution. Moving away from the visual axis the resolution of the eye decreases. Our preferential vision is really only an indicator so we won't be surprised and turn out heads and/or eyes to focus. Probably evolutionary to keep humans from being eaten. The decrease of resolution as a function of angle from the optical axis is not fixed, is a continuum and varies with individuals. That is the reason most likely different people prefer different "normal" lenses ranging from between 35 to 65 to maybe even 75 mm (FF equiv).

Some birds have evolved to have two sets of fovea - one aimed forward to find prey, another aimed to the side "peripheral" vision to spot predators from above/behind.

In general - if I have a "full frame" SLR with a 100% magnification viewfinder and put a 43mm lens on it - I can keep both eyes open and see the same view of the world through both. The eye looking through the SLR is a crop from my full view and has a slight parallax due to the lens being below my eye line.

But otherwise I'm seeing objects in the world the same size in both eyes.

I used to use this trick with zoom lenses - a 0.88 viewfinder magnification - when the world through the lens was the same size as the world through my other eye, I knew I was at 50mm. (50mm * 0.88 = 44mm view)

That's how i'm defining "normal" - the crop from my field of view that's the size of a piece of film.

Really helpful post, Truman. Thank you for taking the time.

-- hide signature --
 saltydogstudios's gear list:saltydogstudios's gear list
Ricoh GR Digital Sigma DP2 Merrill Sigma DP3 Merrill Sigma dp3 Quattro Nikon D7000 +6 more
Truman Prevatt
Truman Prevatt Forum Pro • Posts: 11,062
Re: What I think about when I think about focal length.

saltydogstudios wrote:

Truman Prevatt wrote:

JNR wrote:

saltydogstudios wrote:

JNR wrote:

Really do love those hand drawings - a nice touch.

Back to the topic at hand... that flattening of perspective is most important when considering the actual subject - the person in the portraiture! So - on crop for head and shoulders to an above the waist shot - you have a 50-70mm taken at 5-8 feet roughly that tends to look natural and flattering; at 150-200mm you back off to 15-20 feet and get a flat face with larger ears; and at 35-40mm you step in to 3-4 feet and get the big nose and small ears elongated effect...

That isn't to say you can't use the 35mm for environmental portraiture (or even the 27mm) - just avoid trying to fill the frame by stepping in too close! The 85mm on crop can work well for candids because you are just far enough away - and the flattening of the face isn't quite so accentuated (depending on the angle and facial characteristics).

40mm is (FF equiv) is about "normal" - 43mm actually - and would have relatively little "distortion."

Here's my extensive write up on how I think about various focal lengths.

https://medium.com/ice-cream-geometry/focal-lengths-1a281a3509ed

Focal length "distortion" is about distance from subject and not focal length per-se. If you're a comfortable distance from the subject (which you typically would be with a 43mm lens) you wouldn't get much distortion.

If you were up in their face with a 43mm lens you would, but you probably wouldn't shoot that close with a 43mm lens.

While you clearly understand, how your words express that understanding cause confusion and possible misunderstanding. Where you stand in relation to the subject is perspective. It isn't related to distortion as you are referencing it. If you move forward or backward the translation of the 3D perspective into the 2D mapping will necessarily change those 3D relationships in some form of perceived distortion.

When you interject a photographer's rudimentary understanding of "distortion" which is generally the unfortunate blind acceptance of "rectilinear perspective" - that is nonetheless a type of distortion - often extreme depending on FoV.

Euclidean geometry is not the proper tool for describing photography. All light on a ray are focused on the same point on a sensor. Only one plane is in focus. Looking at an image it is impossible to determine size difference because that depends on the relationships between the locations of the objects relative to the camera.

An exercise I do that's really helped train myself is, when looking at a photo, I ask "where was the camera?"

Imagine myself in the scene taking the photo - where was the camera? What lens was used? etc.

There are often enough context clues to come to some guess about the focal length used and the location of the camera.

For vision, projective geometry is the appropriate geometry because the camera projects all light on a given ray onto the same point. Length and distance is not preserved in projective geometry as it is in Euclidean geometry. Look at the first image in this

https://courses.engr.illinois.edu/cs543/sp2012/lectures/Lecture%2011%20-%20Projective%20Geometry%20and%20Camera%20Models%20-%20Vision_Spring2012.pdf

That's a great presentation.

The infamous McCain "grab" photo is an example of extreme perspective compression.

In reality he was nowhere near Obama and this was just a random moment, but the perspective compression makes it seem like he's gesturing at Obama.

The same with this photo of Obama "checking out" a woman.

Political photos are useful illustrations for perspective compression because they're often taken from so far away. Also sports/action/wildlife.

We have stereo vision because we have two eyes. The camera only has one and hence the images we see coming from our camera are as if we viewed the world with one eye

https://people.southwestern.edu/~futamurf/Day1_2_introtalk.pdf

Projective geometry is the foundation of computer vision.

Taking a drawing class can also be helpful in training you how to "see" the world.

We're so used to the way our eyes see the world that we have to learn to mentally separate and visualize how a camera is different from the eye.

Everything from white balance to perspective geometry to dynamic range. I think a lot of photographers try to perfect all of these things to produce images with the fewest "distortions" - I prefer to exploit how cameras are different from the eye in my work.

("distortions" in air quotes)

There is no way to determine height. One would need a second image from a different perspective and knowledge of locations to do that (stereo imaging). The techniques of computer vision are based on projective geometry not Euclidean geometry. The size relations between objects are determined by the lateral magnification and axial magnification of the lens and are a function of the focal length. The greater the focal length the greater the magnification. It is the magnification - in particular the axial magnification that introduces the near to far distortion seen in lenses from the big nose small ear wide angle effect to the flatten telephoto effect. Below is the same scene and in the frame the girl is the same size relative to the frame but look at the bridge.

https://photography.tutsplus.com/tutorials/exploring-how-focal-length-affects-images--photo-6508

The size of the bridge relation to the woman appears larger in the telephoto that the wide angle although in reality no size changes.

That's a great illustration of the kind of mental exercise I'm talking about - look at a photo, ask yourself "what is the focal length of the lens, where was the camera?"

Once we accept that the Euclidean geometry is not the appropriate description of the projection of three dimensions onto a plane, then a lot of concepts in photography and visual arts in general become much more clear. What some call distortion (lateral distortion in the image) arises because projective geometry does not preserve distance as Euclidean geometry does. The front to back compression distortion is because of the difference in axial magnification in an image and is a function of focal length solely.

I suppose telecentric lenses are an exception to this rule.

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

The eye is very complex. It is only in a narrow field of view that our vision is high resolution. Moving away from the visual axis the resolution of the eye decreases. Our preferential vision is really only an indicator so we won't be surprised and turn out heads and/or eyes to focus. Probably evolutionary to keep humans from being eaten. The decrease of resolution as a function of angle from the optical axis is not fixed, is a continuum and varies with individuals. That is the reason most likely different people prefer different "normal" lenses ranging from between 35 to 65 to maybe even 75 mm (FF equiv).

Some birds have evolved to have two sets of fovea - one aimed forward to find prey, another aimed to the side "peripheral" vision to spot predators from above/behind.

The corpus callosum is the communication channel between sides of the brain. This is what allows humans to have stereo vision the the signals for each eye is shared with the other side of the brain so the image can be produced. It is difficult for us to view the world in projective space. Not all mammals have a robust corpus callosum like humans, for example the horse. The horses eyes are vastly different. When a horse it grazing he can see 360 degrees to detect a predator. That's what happen when you evolve as someone else's meal. However, the eyes and brain sides act independently. That is if a horse spooks at something when you pass it on the left and you stop and get the horse acclimated to the object out of his left eye. When you come back by it in the opposite direction he will most likely spook out of his right eye.

It is instructive for people to put on an eye path and walk around to see how the world appears. With infinite DOF - there are no clues in a photo on relation of two objects since all photons on a ray are focused at the same point of the sensor. So by placing two people six feet tall 20 feet apart by moving around in a circle around them a photographer can make either look much taller by where he is located. DOF and bokeh will give a clue but without it there are no clues on size and distance. The image of Obama and McCain is a good example. No McCain was not trying to play grab ass. It was the placement of the camera in the projective space that describes the geometry. That's a reason that robots require multiple cameras so that time of ambiguity can be sorted out if they are to be able to independently navigate in the world.  Our two eyes and our brain merging the different images out of our eyes - results all to often not taking into account how a camera sees the world by project three dimensions on to a plane.

In general - if I have a "full frame" SLR with a 100% magnification viewfinder and put a 43mm lens on it - I can keep both eyes open and see the same view of the world through both. The eye looking through the SLR is a crop from my full view and has a slight parallax due to the lens being below my eye line.

But otherwise I'm seeing objects in the world the same size in both eyes.

I used to use this trick with zoom lenses - a 0.88 viewfinder magnification - when the world through the lens was the same size as the world through my other eye, I knew I was at 50mm. (50mm * 0.88 = 44mm view)

That's how i'm defining "normal" - the crop from my field of view that's the size of a piece of film.

Really helpful post, Truman. Thank you for taking the time.

-- hide signature --

_____
"The winds of heaven is that which blows between a horse's ears," Arabic Proverb
__
Truman
www.pbase.com/tprevatt

 Truman Prevatt's gear list:Truman Prevatt's gear list
Fujifilm X-H1 Fujifilm X-Pro3 Fujifilm XF 18mm F2 R Fujifilm XF 35mm F1.4 R Fujifilm XF 55-200mm F3.5-4.8 R LM OIS +10 more
saltydogstudios
saltydogstudios Senior Member • Posts: 2,173
Totally Of Topic Post About Brainzzzzzz
1

Truman Prevatt wrote:

As for "normal" as our eyes see it - I also accept the general notion of the diagonal measure explanation resulting in 43mm in FF (29mm in Fuji crop), but our eyes are much more complex than that single translation. We see much wider, but focus much narrower, and so on... as has been endlessly discussed.

The eye is very complex. It is only in a narrow field of view that our vision is high resolution. Moving away from the visual axis the resolution of the eye decreases. Our preferential vision is really only an indicator so we won't be surprised and turn out heads and/or eyes to focus. Probably evolutionary to keep humans from being eaten. The decrease of resolution as a function of angle from the optical axis is not fixed, is a continuum and varies with individuals. That is the reason most likely different people prefer different "normal" lenses ranging from between 35 to 65 to maybe even 75 mm (FF equiv).

Some birds have evolved to have two sets of fovea - one aimed forward to find prey, another aimed to the side "peripheral" vision to spot predators from above/behind.

The corpus callosum is the communication channel between sides of the brain. This is what allows humans to have stereo vision the the signals for each eye is shared with the other side of the brain so the image can be produced. It is difficult for us to view the world in projective space. Not all mammals have a robust corpus callosum like humans, for example the horse. The horses eyes are vastly different. When a horse it grazing he can see 360 degrees to detect a predator. That's what happen when you evolve as someone else's meal. However, the eyes and brain sides act independently. That is if a horse spooks at something when you pass it on the left and you stop and get the horse acclimated to the object out of his left eye. When you come back by it in the opposite direction he will most likely spook out of his right eye.

That's really interesting about horses.

The corpus callosum is interesting in humans too. "Split brain people" - people who've had their corpus callosum cut, typically in an effort to reduce the impact of seizures show some of what the corpus callosum does - if you show an object to someone's right brain they'll say "it's round, it's red, you can eat it" - but can't. name it. If you show their left brain they'll say "it's an apple" but can't describe it. (I may have the left and right swapped in this example.) If you ask one half of the brain to get up and walk around the table, they will - and if you ask the other half of the brain why, they'll invariable come up with a (made up) reason. They're also more likely to develop alien hand syndrome (aka dr strangelove syndrome). The final fascinating tidbit on split brain people - in order to come to a decision they literally do a "gut check" - the way the two halves of the brain communicate is through the body.

It is instructive for people to put on an eye path and walk around to see how the world appears. With infinite DOF - there are no clues in a photo on relation of two objects since all photons on a ray are focused at the same point of the sensor. So by placing two people six feet tall 20 feet apart by moving around in a circle around them a photographer can make either look much taller by where he is located. DOF and bokeh will give a clue but without it there are no clues on size and distance. The image of Obama and McCain is a good example. No McCain was not trying to play grab ass. It was the placement of the camera in the projective space that describes the geometry. That's a reason that robots require multiple cameras so that time of ambiguity can be sorted out if they are to be able to independently navigate in the world. Our two eyes and our brain merging the different images out of our eyes - results all to often not taking into account how a camera sees the world by project three dimensions on to a plane.

Yes, though my understanding is that the binocular effect decreases with distance. It's most helpful within an arm's length - so you can properly gauge how far away that coffee cup is.

The average human's eyes are ~54-74mm apart (according to Google). By the time you get to 600mm - or or 0.6 meters - that's about 1% difference between the two eyes relative to the distance of the object. So by 2 meters that would be 0.25% and so on.

I experienced this the other day - I was looking at some bicyclists who were maybe 20 meters away and I couldn't tell if they were coming towards me or going away from me (it was dark so I just saw the silhouette).

-- hide signature --
 saltydogstudios's gear list:saltydogstudios's gear list
Ricoh GR Digital Sigma DP2 Merrill Sigma DP3 Merrill Sigma dp3 Quattro Nikon D7000 +6 more
DomiDarko
DomiDarko Regular Member • Posts: 138
Re: 50mm f2 vs 35mm 1.4 - which has more bokeh?
1

A thread about bokeh and not once did I see the term ‘buttery’ or creamy, cheesy bokehlicious.

-- hide signature --

There are no rules that constrain art. Shoot what you want, how you want and with whatever gear you want.

 DomiDarko's gear list:DomiDarko's gear list
Fujifilm X100T
JayPhizzt Senior Member • Posts: 1,590
Re: 50mm f2 vs 35mm 1.4 - which has more bokeh?

DomiDarko wrote:

A thread about bokeh and not once did I see the term ‘buttery’ or creamy, cheesy bokehlicious.

Well, the thread is really more about depth of field than bokeh.

 JayPhizzt's gear list:JayPhizzt's gear list
Fujifilm X-T3 Fujifilm XF 16mm F1.4 R WR Fujifilm XF 80mm F2.8 Macro +1 more
Truman Prevatt
Truman Prevatt Forum Pro • Posts: 11,062
Re: 50mm f2 vs 35mm 1.4 - which has more bokeh?

JayPhizzt wrote:

DomiDarko wrote:

A thread about bokeh and not once did I see the term ‘buttery’ or creamy, cheesy bokehlicious.

Well, the thread is really more about depth of field than bokeh.

Actually they are sort of related don't you think?

-- hide signature --

_____
"The winds of heaven is that which blows between a horse's ears," Arabic Proverb
__
Truman
www.pbase.com/tprevatt

 Truman Prevatt's gear list:Truman Prevatt's gear list
Fujifilm X-H1 Fujifilm X-Pro3 Fujifilm XF 18mm F2 R Fujifilm XF 35mm F1.4 R Fujifilm XF 55-200mm F3.5-4.8 R LM OIS +10 more
Greg7579
Greg7579 Forum Pro • Posts: 10,808
Like me Some Bokehliciousness....

JayPhizzt wrote:

DomiDarko wrote:

A thread about bokeh and not once did I see the term ‘buttery’ or creamy, cheesy bokehlicious.

Well, the thread is really more about depth of field than bokeh.

You Fuji X shooters should cherish your DOF.  You have a lot off it.  Don't be afraid to use it.  Diffraction be damned!  Shoot F11 or 16 if you want and buy some damn DOF....

You don't have to shoot wide open with those fast lenses.  Come on....

But I do like me some bokehlicious, creamy and buttery bokeh from time to time, especially if it is not me trying to do it but instead admiring the work of the great portrait and fashion pros.

I remember a while back Benjamin was shooting a model from way back using a 200mm lens wide open at F2 and he had all of that subject isolation and he said he loved that tasty bokehliciousness....  But I think he was using a 7000 dollar Nikon 200 F2.  😁

-- hide signature --
 Greg7579's gear list:Greg7579's gear list
Leica Q2 Fujifilm GFX 50R Fujifilm GFX 100 Fujifilm GF 32-64mm F4 Fujifilm 120mm F4 Macro +6 more
Keyboard shortcuts:
FForum MMy threads