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Depth of Field on the M43 is in fact better not worse.....
- Thread starter BushmanOrig
- Start date
BushmanOrig
Senior Member
What you say cannot be more true..... I see it myself, because I spend much time preparing articles and getting to know the camera I do not go out as much as normal. Today I was out and not only did I enjoy it I also made a few changes to my settings based on real life needs....
I would add read up on a subject to your input - how many people add input, and its great to have that....but without reading or searching info first....
Great landscape was that the E1?
Best
Siegfried
Community of Photographers
http://www.photographyisfun.ch
I would add read up on a subject to your input - how many people add input, and its great to have that....but without reading or searching info first....
Great landscape was that the E1?
Best
Siegfried
--Despite what many may say, I have never had an issue with achieving the DOF that I need. If I want max DOF for landscape, no problem. If want just a sliver of DOF for taking captures of flowers, no problem either. It is prudent to have an understanding of the inherent short comings of a given capture system such as lens softness at a particular aperture. However, no offense intended, people need to stop complaining about various inadequacies of (m)4/3 and just go out and take photographs.
Taken with an E-1
Taken with an EP2
Taken with an EP2
--
http://flickr.com/photos/bjanderson/
Community of Photographers
http://www.photographyisfun.ch
bobn2
Forum Pro
Playing fast and loose with the facts, again 'boggis'?
Jim: Well folks have been saying that the extortionate Olympus 300mm F2.8 {UK £5700} is really a 600mm F2.8
boggis: That would be because it is.
http://forums.dpreview.com/forums/read.asp?forum=1022&message=39410248
So it seems that the one who goes around saying things "really are" what they are not is you, not the 'equivilators'.
--
Bob
Not quite, a 75-200/4.2. It will take the same range of pictures as a 75-200/4.2 would on his D800.
The 'equivalators' have never said that. What they have said is that it is 'equivalent to' an f/4.2 lens on FF. It's only you who continually lies about what the 'equivilators' say, presumbaly because you have nothing to counter it in the way of evidence. By the way, is 300mm really 600mm, or not?
Jim: Well folks have been saying that the extortionate Olympus 300mm F2.8 {UK £5700} is really a 600mm F2.8
boggis: That would be because it is.
http://forums.dpreview.com/forums/read.asp?forum=1022&message=39410248
So it seems that the one who goes around saying things "really are" what they are not is you, not the 'equivilators'.
Or in your case, maybe you just need to learn to tell the truth occasionally.
--
Bob
bobn2
Forum Pro
I see some issues with your article.
Let's take your statement:
Depth of field is effected by subject distance, aperture size and focal length. If any one or more of these three variables change then the DOF will change.
Now, let's compare your statement with the one in the Wikipedia article on DOF
For a given image format , depth of field is determined by three factors: the focal length of the lens, the f-number of the lens opening (the aperture), and the camera-to-subject distance.
http://en.wikipedia.org/wiki/Depth_of_field
Can you spot the important rider that you have missed out? I emboldened it above. Interesting that having ignored the format issue, you then build it in again by using lenses that give the same AOV on the different formats you consider, but ignore that the amount of enlargement that you need to get the same final image size is different on different formats. The effect of that different enlargement factor is that when you do your DOF calculations you need to use different circles of confusion (COC) to get the same result in the different formats.
So as you don't have to do all that calculation, it is already in the Wikipedia article I quoted, and for the same DOF on different formats the formula is
where 'N' is f-number, and 'l' is liner dimension of the sensor.
So, we use that and we find out that if we take your example of a 150/5.6 on a mFT, then that gives the same DOF as 187/7 on Canon APS-C and 300/11 on FF. Conversely, the 300/5.6 on FF is giving the same DOF as 150/2.8 on mFT, while the 187/5.6 on APS-C is giving the same DOF as a 150/4.5 on mFT. Now, contrary to your statement that 'the 300mm lens at f5,6 on the 5D will be more expensive than the 14 - 150mm Olympus lens. The same is true for the 7D.', all you need is a 300mm lens that gives decent perfomance at f/11, which are two a penny, while for APS-C you need a 200 that is OK at f/7, which are also not hard to come by economically.
Then If the distance to the subject and the focal length stay fixed then the M43 camera will create the same DOF with a maximum lens aperture of f1,8 as what the Canon lens will do with a maximum aperture of f1,4 /
But if the subject distance and FL stay fixed, then what you have is a completely different picture . 50mm is a standard lens on FF, a telephoto on mFT, what is the point of comparing DOF for completely different pictures?
Then, when it comes to the bit on getting more depth of field, I'm a bit unsure of your advice to 'simply move further away from the subject', I foresee a lot of people falling down holes, canyons and the like. Would it not be simpler to advise to simply stop down more, as would most photographers?
Then comes you pictorial comparison, where you show a 5DIII, a 7D and a E-M5 all fitted with equivalent FL's at the same distance and the same f-number (more or less). Surprise, the 5DIII gives shallowest DOF, followed by the 7D with the E-M5 giving deepest DOF, exactly what might be expected, as opposed to you artical which suggests that these DOF's are exactly the same .
Your article denies itself. Go with your test images, not with your discussion, which, I am afraid, is just wrong.
--
Bob
In my haste, I failed to complement you on your article about DOF. The article was very well done. Very clear and concise and a must read article for individuals seeking clarity with regard to differences within the realm of DOF when compared to different sensor architectures/FOV. I will be bookmarking your site.
Absolutely agree with you on this. I like to scout potential subjects. I'll take notes on lighting conditions and document what time of day is the most ideal for capturing conditions. I will also will note how weather may impact lighting conditions and the impact the relationship between the weather and light may have on the subject.
As a landscape photographer (I am not a pro) I like to think that I am taking pictures of weather and not geology. It is always my goal to capture the very essence of a landscape scene. In other words when I look at a landscape capture that really appeals to me I like to get a sense as to the time of day the photograph was taken. I like to be able to get a sense as to what time of year the photo was taken. ex: summer, winter, spring, fall. I like to see that a scene has a quality of light that highlights certain features of the landscape scene. I want a photograph to leave an imprint within my visual memory that I won't forget. I want to remember the spirit of a landscape scene and not its geology. It is the totality of the qualities that I described above that differentiate a good photo from one that takes your breath away. Sometimes you may get lucky and stumble upon such a scene but, more often than not, it has been the mere fact of knowing your subject and the inherent quality of the conditions that has made the difference.
Thanks! Yes, the landscape was taken with the E-1.
--Best
Siegfried
--Despite what many may say, I have never had an issue with achieving the DOF that I need. If I want max DOF for landscape, no problem. If want just a sliver of DOF for taking captures of flowers, no problem either. It is prudent to have an understanding of the inherent short comings of a given capture system such as lens softness at a particular aperture. However, no offense intended, people need to stop complaining about various inadequacies of (m)4/3 and just go out and take photographs.
Taken with an E-1
Taken with an EP2
Taken with an EP2
--
http://flickr.com/photos/bjanderson/
Community of Photographers
http://www.photographyisfun.ch
http://flickr.com/photos/bjanderson/
Jonas B
Forum Pro
Then you have found a truth working fine for you (and a system meeting your needs). The problem is there for those either wanting to discuss system differences all the time, or wanting to isolate something bigger than flower or heads from the background. Then a system with a larger sensor usually works much better.
But... if that is the prime goal there is no reason to neither discuss nor buy into the world of µ4/3.
Jonas
If I am understanding your post properly . . . I have no problem with intelligent discussion with regards to many aspects of photography and the differences with equipment. I have learned so much from such discussion.
The beauty of the current state of this photographic era is that we have so many options to suit our photographic needs. It is awesome how many options we have; 135, APS-C, 4/3, m4/3 and everything in-between. If you have certain needs, such as subject isolation, and 4/3 isn't working for you then you have options. This toughest part is not deciding on one particular system to suit your needs. The toughest part, and I am speaking for myself, is having the funds to keep up with the constant improvements in technology within the realm of image capture devices.
Not exactly sure what you mean by "if this is the prime goal." From the perspective of my photographic goals, yes (m)4/3 is meeting my needs. I understand the inherent issues that (m)4/3 has and I am able to adjust my technique to accomplish my goals. I know this won't work for everyone. Like I have said, if this is the case then you have other options outside of (m)4/3. It is nice to have these options.
--
http://flickr.com/photos/bjanderson/
BushmanOrig
Senior Member
Hi Bob
Thank you for your well thought through feedback. The challenge with an article or feedback in this case is to keep it simple as I said in the article. The article was really aimed at the inexperienced with DOF and I wanted to leave a clear and workable image with the reader. Question is, did I achieve that and secondly did your feedback add to that or did it leave the reader with no understanding?
While reading/studying your feedback I could not help thinking......does this help the novice, will it leave the beginner with a clear enough 2 or 3 points to go away and correct or improve any incorrectness my article created in the readers technique?
To answer you on some of your points, I basically decided not to do that. My main sources listed in the article are DPR & 123di.com. I studied the more advanced theory in 123di.com when preparing myself for the article and after much consideration I decided not to go to CoC level or depth as it will not help building that basic image I wanted with the reader. Wikipedia, I think its a good source but only a basic reference in my opinion- I will not base an article on the info I see in Wikipedia.....
Bob I had several mails from readers saying thanks & asking more questions plus as you see in the discussion. I feel confident that many readers will be able to build a good understanding of DOF from the article plus will be able to improve.
As with other readers feedback I am happy to update obvious mistakes. You welcome to provide me with one or two basic and clear points.....
Best
Siegfried
--
Community of Photographers
http://www.photographyisfun.ch
Thank you for your well thought through feedback. The challenge with an article or feedback in this case is to keep it simple as I said in the article. The article was really aimed at the inexperienced with DOF and I wanted to leave a clear and workable image with the reader. Question is, did I achieve that and secondly did your feedback add to that or did it leave the reader with no understanding?
While reading/studying your feedback I could not help thinking......does this help the novice, will it leave the beginner with a clear enough 2 or 3 points to go away and correct or improve any incorrectness my article created in the readers technique?
To answer you on some of your points, I basically decided not to do that. My main sources listed in the article are DPR & 123di.com. I studied the more advanced theory in 123di.com when preparing myself for the article and after much consideration I decided not to go to CoC level or depth as it will not help building that basic image I wanted with the reader. Wikipedia, I think its a good source but only a basic reference in my opinion- I will not base an article on the info I see in Wikipedia.....
Bob I had several mails from readers saying thanks & asking more questions plus as you see in the discussion. I feel confident that many readers will be able to build a good understanding of DOF from the article plus will be able to improve.
As with other readers feedback I am happy to update obvious mistakes. You welcome to provide me with one or two basic and clear points.....
Best
Siegfried
--
Community of Photographers
http://www.photographyisfun.ch
boggis the cat
Veteran Member
"Again"?
One of those "Have you stopped beating your wife yet" gambits, eh, Bob?
I calculated the "equivalence" on the actual sensor sizes in mm^2. That is probably why there is a discrepancy.
But that all depends on what you're trying to achieve by way of equivalence. In this case, you want an equivalent DOF.
Oh, I'm one of those many people who continually points out that "f/2 = f/2 = f/2" as you well know, Bob.
As you also well know, there are plenty of examples of people claiming that lenses on one format are a different relative aperture based on mis-application of "equivalence" -- just read through the recent Panasonic 12-35 f/2.8 and Olympus 75 mm f/1.8 comments.
http://www.dpreview.com/news/2012/05/21/Panasonic-12-35mm-F2-8-fast-standard-zoom-for-micro-four-thirds#comments
This lens is equivalent to 24-70/5.6 on FF. How much such lens costs for FF? Maybe $200. Panasonic is going to sell those for at least $500, if not more.
You do the math.
Let me get this right. They are going to charge similar prices for an equivalent 24-70mm 2.8 when it uses LESS OPTICAL GLASS. Oh, but you pay more for less but it is lighter. Yeah, a lighter wallet.
Two posts mentioning differing forms of equivalence, and both correct or incorrect depending on what equivalence you mean.
Since you know this, you are not being truthful with your claim here, are you? Attempting to gloss over and obscure the problems with the fast and loose use of "equivalence" seems to be your mission whenever a critical post crops up.
In angle of view terms, 300 mm of FT is equivalent to 600 mm on 135 -- hence the "600 mm EFL" designation.
Out of context quote-mining somehow equates use of EFL to "equivalence" in your mind?
BTW, did you notice the "
" ending my post? I had no doubt that the ChrisDM understands "equivalence" fine, and also understands that it isn't relevant.Whatever you say, "Honest Bob".
Yet another fact-free (aside from a calculation error) personal attack response to add to your collection of "educative" posts. No doubt you'll profess surprise and indignation when you eventually get banned again for your "contributions".
How about you try to stick to factual information -- or is that a losing proposition given what a dog's breakfast the "equivalence" application is? What do you say, Bob -- can you make a case for continuing with the current confusion caused by "equivalence", or is it way past due to sort it out?
You know my opinion.
boggis the cat
Veteran Member
I agree completely.
We have a band of "equivalence" proselytizers jumping into threads to "correct" posts such as yours on the basis that DOF / absolute light gathering is the only meaning for "equivalent".
(Thus the
at the end of my "thou hast taken the name of equivalence in vain" style reply.)This is a a nonsense, and also leads to other people picking up on the "equivalent" relative apertures and thinking that these are the real relative apertures for exposure purposes.
If you want shallow DOF with wide-angle then you are better served with a larger sensor system, certainly.
For my shooting that isn't important so I can ignore it when considering system options. It all comes down to understanding what will work best for your particular requirements.
Detail Man
Forum Pro
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Hi Siegfried ,
While the implementing of correcting may indeed on your part be complicated, it seems that Bob's basic and clear points were that the assumptions that you relied upon were incorrect. In that such is the case, all derivations from those premises would be flawed by being incorrect information. The business regarding the effect of the Field of View upon final presented image sizes is indeed a nasty gremlin that I, myself have preferred to at times ignore. But doing so did not make it correct
There is another way around that, but it necessarily involves cropping images - which reduces Field of View as well as reducing pixel-resolution. Perhaps worthwhile - but a very notable difference ...
DM ...
R
Ron Parr
Guest
I tired to send you a personal email about this but it bounced. I'm sorry to say this in a public forum, but I have to say your text is doing more harm than good. It leaves out key information and is in contradiction with the images you have posted.
You start with an incorrect definition of DOF:
"DOF is therefore the area that is in focus in the image."
DOF isn't an area in the image; it's range of depths in the world that appear in focus in the image.
Things go downhill from there. You say that you are trying to make things simple for novices, but giving them incorrect and inconsistent information isn't helping them.
--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/
You start with an incorrect definition of DOF:
"DOF is therefore the area that is in focus in the image."
DOF isn't an area in the image; it's range of depths in the world that appear in focus in the image.
Things go downhill from there. You say that you are trying to make things simple for novices, but giving them incorrect and inconsistent information isn't helping them.
--
Ron Parr
Digital Photography FAQ: http://www.cs.duke.edu/~parr/photography/faq.html
Gallery: http://www.pbase.com/parr/
Rick Baumhauer
Forum Enthusiast
I don't think it's m43 owners that insist on saying that the DOF from their setup isn't shallow enough. It seems to be primarily people who don't shoot with m43 that always bring this up, as if shallower DOF is automatically better, or there is no lower limit on DOF beyond which only other photographers are impressed, and only because they know that, to get such thin DOF, you had to be shooting with very expensive glass.
boggis the cat
Veteran Member
While I see what you mean, that's a rather odd way to put it -- which brings us to the problem of trying to tailor what you write to a specific audience.
DOF is an apparent effect. A lens only focuses at a plane (or near-planar curved field, in most cases) and the appearance of objects in front of or behind that plane becomes increasingly blurred. In practice, you want an idea of how changing aperture will affect the appearance of elements within the image that is recorded.
Perhaps "The DOF is the distance between the closest and most distant planes where objects would appear to be reasonably sharp in the image" would be better -- but you can see that it starts to become unwieldy.
What a beginning photographer really wants to know is answers to practical concerns, rather than details that don't add anything useful. Given the example photos used I don't see much problem with Siegfried's choice of wording.
I haven't read Siegfried's article in detail as yet, but bear in mind that he wishes to provide a practical and easily understood article to assist people to grasp the most basic concepts of DOF. The photographs showing background blur are exactly what such people need to help them grasp those basics, in my view.
Sometimes striving to provide all of the details will overwhelm the person reading and obscure the important details that they actually need to grasp.
(I am not sure where the inconsistency you mention occurs. Perhaps you could point that out?)
BushmanOrig
Senior Member
Bobn2, Detail Man and Ron Pair I read your feedback again plus the parts in the article you pointed out.
As said before the aim was to keep it simple and to let the reader go away with a easy set of rules to go and practice back ground blur plus DOF.....
I therefore removed those parts that could bring confusion plus those parts that really were aimed at the formats.....sorry for that....could not resist;-)
Boggis the Lion thanks for your final input....
I hope I can now close the article and that it will be useful in the future to others...
Siegfried
--
Community of Photographers
http://www.photographyisfun.ch
As said before the aim was to keep it simple and to let the reader go away with a easy set of rules to go and practice back ground blur plus DOF.....
I therefore removed those parts that could bring confusion plus those parts that really were aimed at the formats.....sorry for that....could not resist;-)
Boggis the Lion thanks for your final input....
I hope I can now close the article and that it will be useful in the future to others...
Siegfried
--
Community of Photographers
http://www.photographyisfun.ch
bobn2
Forum Pro
Not really, just making the point that you are a serial offender when it comes to playing fast and loose with the facts. I have no information about your relationship with your wife (nor do I want any).
The relationship is with linear dimension. For sensors of different aspect ratios, you need to decide which linear dimension is important to you, and people often go with diagonal as a compromise. The difference is small, in any case. Area really doesn't cut it, since we rarely decide on image output size by area.
No, the issue here is whether anyone has actually said. that an f/2.8 lens on FT is 'really f/4.8', as you say they do. In fact the 'equivilators' say it is equivalent/ to f/4.2 on FF, for DOF, photon noise and diffraction blur for the same subject and shutter speed. That's because it produces the same results for all those things, all else, as they say, being equal.
I know, and I'm one of those people who never says 'f/2 = f/2.7 = f/4', although if you realise that the 'f' is different in each case, then it 'really' does. So imagine we have f₁ = 25mm (a Four Thirds 'normal'), f₂ = 33mm (an APS-C normal) and f₃ = 50mm (a 'full frame' normal) then we find that f₁ 2 = f₂ 2.7 = f₃ 4 = 12.5mm.
I asked you to find me an example of someone saying that last time you raised that canard, and you couldn't, and you still can't. That list of comments doesn't contain a single post with someone claiming that lenses on one format 'are' a different relative aperture on another. There are comments saying that one f-number on one is equivalent to another f-number on another, and generally they are right.
That comment is well founded. Note the use of the word 'equivalent', not 'is'.
Note also the use here of the word 'equivalent', not 'is'.
but neither says 'is', they both say 'equivalent', whereas you were claiming that 'the equivilators' say it is 'really f/4.8'. And you have patently failed to produce evidence for this, so it has to go down as one big, fat lie until you do.
I am indeed being truthful, and you are being mendacious. See above.
'equivalence' is a relative terms, and always needs context. Saying people said something is 'really' something else, when what they said is that it is 'equivalent' to something else is just dishonest.
Yup, but you didn't say it was 'equivalent', you said it 'is' 600mm. And so the nub of it is if it is OK for you to say that 300mm (mm being a well defined unit) is 'equivalent' to 600mm, then there is not a problem with saying f/2.8 on one format is 'equivalent' to f/5.6 on another, is there? (and as far as units go, we are still talking in mm)
How is it 'out of context', anyone go back and read the full context and they can see that you were saying unambiguously that 300mm F2.8 'is' 600mm F2.8.
A 'BTW, did you notice the "
' doesn't cover for lying.Indeed, good advice, else you get a reputation for mendacity.
No personal attack except to point out that you weren't telling the truth, and you weren't.
Factual information is what I deal in, and non-factual misinformation is what you deal in.
The 'confusion' is caused not by 'equivalence' but by the attempts of you and your ilk to muddy the waters and deny facts to suit your tired fanboy agenda. If you were capable of understanding it, you'd realise that the optical principles called 'equivalence' are exactly what the Four Thirds system is designed around, that for 'equivalent' photos, sensor size is relatively unimportant, so there are practical gains to be had making the sensor smaller.
Oh yes, indeed I do. I just don't think it has any value.
--
Bob
boggis the cat
Veteran Member
Which is why your post is simply a series of personal attacks, information man.
Keep it up Bob. Got your next alias picked out yet?
bobn2
Forum Pro
Hi Siegfried,
I think there is always a problem trying to explain the basics of a complex subject to a beginner, especially if what you are trying to do is lay the framework for the gathering over time of a more complete knowledge. There are those who think that it's OK to change the facts and theory to make it simpler, but my experience is that people subject to that kind of introduction suffer from conceptual blocks caused by a wrong cognitive framework which stop them from progressing further.
I think one needs to go back to think why a novice photographer might want to know about DOF, and I think the answer is to be able to control DOF in their final photo, therefore I think that you need to consider your treatment from that starting point, the final photo as a whole and taken together with the other things in the photo people want to control.
I may be wrong, but I think DOF is something that comes quite late in mastering the craft of photography. By and large, people have learned about the affects of subject distance and FL in some qualitative way before they get to DOF.
Then, most people are single format users, so any starting treatment can ignore differences between formats. When it comes to translating between formats the 'equivalence' rule (multiply the f-number by the crop factor to get the same DOF) is very simple and easy for people to grasp - the controversy isn't really around DOF equivalences, it is the other ones, noise and diffraction, that come with it, but an article on DOF alone doesn't have to cover that.
Anyway, if you are interested in DOF control, can I suggest a good 'non-conventional' source:
http://www.trenholm.org/hmmerk/DOFR.html
I like his simple rule and simple method, especially for extended DOF. Just remember that the aperture size defines the minimum feature size for objects in front of the point of focus, and everything gets quite simple in the field. For example, If i'm using 24mm at f/8, then my aperture size is 3mm. So, I look at objects in the foreground and think if I can see a 3mm feature on that, is it sharp enough.
--
Bob
bobn2
Forum Pro
It is a fact that you are not telling the truth, therefore what I say is factual information. And as we see here, rather than provide evidence that you are telling the truth (in which case I'd have to withdraw the statement) all you do is engage in irrelevant personal attacks of your own.
I've had this one six years now, and the only reason I had an interregnum where I needed new ones is that your friend the Artificer Sergeant-Major was running a complaint button campaign against me to distract from inconvenient facts which didn't fit his (and your) fanboy agenda. He even bragged about it, so there's not much disputing it. Anyway, the question that I got banned a lot for telling the truth has no bearing at all on your mendacity.
--
Bob
ChrisDM
Senior Member
Are you kidding? in the world ??? Did you miss the part where the OP states that he wrote this article for the beginner to begin to grasp these concepts as they relate to photography? And you want to nitpick the definition of DOF to that level? He's not writing an scientific optics textbook. Once again it is for the beginner to grasp the concept. And his definition does that just fine, in fact better than yours.
Chris
http://www.imagineimagery.com
--
Chris
http://www.imagineimagery.com
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