Full Frame advantage real?

[Dan62326]

Read the essay
yet? 'Cause it's answered in it:
Go down to Myth #5: Larger sensors require sharper glass and have
softer edges.

I'll quote it here for you:

Yes, I do recall reading that part when you posted the link. But after all this discussion and browsing, not everything was perfectly retained in memory =) It takes a multifaceted approach to teach me something. And as I learn, I'll ask questions to make sure I understand a certain thing. This subject alone could be a college course =)

If the 1.6x sensor and FF sensor had the same number of pixels, had
the same design and efficiency, and we shot the same scene at the
same FOV, DOF, and shutter speed, then, yes, if the 1.6x lens was
1.6x times sharper everywhere in the image circle, they'd be as equal
as you'd ever be able to get two images from different format systems.

Of course, in practice, we don't get any of those ifs in terms of
the lenses.

This was one of those questions I asked to see if I understood the theory =)

 

[Dan62326]

It is critical to remember
that the "out of focusness" of a crop image will be enlarged more to
achieve a given print size than the "out of focusness" of a full
frame image, since the latter starts larger.

Does this mean that the background blur of the image from the crop
sensor will look the same as the background blur from the FF image
(when the image is printed at the same size)?

For the same FOV and DOF, yes.

I realized that you answered that question when you pointed out the DOF of the D2x vs 5D images. One was shot using an 85mm lens and the other was with a 50mm. However, the F-ratio's were the same so the 5D shot had less DOF.

So FF DOES have an out-of-focus blur advantage.

Anyway, your asking hypothetical questions about hypothetical
systems, which, of course, is all fine and dandy, as it helps form an
understanding about the principles at work,

Yes, I try to treat this like a mathematical proof...I think. It's all about presenting the facts in a way one can understand them.

It's not enough for me to hear someone just say that FF just looks better and is more film-like.

let's discuss
some of the important "real world" differences between crop and FF:

1) Larger sensors have less shot noise and more read noise. What
this means is that larger sensor systems produce much cleaner images
at low ISOs when there is ample light, but when upping the ISO to
maintain the same DOF and shutter speed in a limited light
environment, the darker areas of the image from a larger sensor will
exhibit more noise.

For shooting weddings, this usually isn't a problem as I usually go for less DOF. So the advantage goes to FF.

2) The MTFs of some FF lenses exhibits a sudden drop at the exteme
edges. This means that cropped sensor systems using FF glass will
not experience this sudden drop, as this portion of the image is
cropped out, and the extreme corners (5% of the total image area) may
be sharper,

even though the rest of the image will be softer.

softer because of?

3) While I know of no example where cropped glass is sharper by a
factor of the crop factor, most cropped glass is sharper than their
FF counterparts. Thus, while FF will still be sharper overall, the
difference is not as exteme as some make it out to be.

And this is because the balls hit the larger squares more easily than they do the smaller squares (assuming the same number of squares on both setups)?

why else would landscape photographers be using
a tripod and MLU?).

I thought it was macro photographers that used MLU. It seems that the amount of shake the mirror would induce wouldn't affect a landscape capture.

Finally, there's print size. For an 8x12 print,
300 PPI only requires 8.64 MP. On the other hand, 300 PPI for a
12x18 print requires 19.44 MP. So, how big are you printing? Even
so, just how big of a difference will 200 PPI, or even 150 PPI vs 300
PPI matter to you?

Doesn't more MP's mean finer grained noise that is less noticable?

It's important to understand the advantages/disadvantages of the
equipment. But this can all too easily be taken to an extreme where
it is well past the point of having any meaningful purpose.

I'm pretty sure this is true now, but it makes me wonder when people say things like, "Guess which camera I'm going to grab when quality matters?" It's as if they're implying that there is a HUGE difference in IQ and that it would be silly to use the other cameras.

 

[Dan62326]

a larger sensor has the ability to capture more light

ok

greater detail

no, this would depend on how many pixels the sensor has

resolution

no, again this would depend on how many pixels the sensor has

and dynamic range.

no, only pixel size affects dynamic range and not sensor size

 

[Dan62326]

Could it have been luck? Yeah, it sure could have been. But she was
really sure of her choice. There was no hesitation. Could I tell
the difference? Impossible to say as I knew not only which camera,
but which lens was used for each pic. I was far from unbiased. : )

Hehe, I like this story. I don't think it was luck at all.

So, what's my point? Maybe the 5D was that much better, maybe she
just got lucky. What do I think? I think the 5D was better, but
that only someone really attuned to scrutinize an image could tell.
I don't think most people could've told the difference, or even cared
about the difference if they could.

Sometimes I think we give people less credit than we should. There are often things that can't be put into words but are perceived.

I used to own a 20D and I was comparing some pictures to ones from my D1x and I felt that the D1x images were much more pleasing to the eye. It may have been the tone curve as I noticed that the 20D was making things in the shadows much brighter.

Did you process all those prints you showed her from RAW files?

I'm wondering if there was some difference in processing that she noticed.

Seems like it's not a FF vs crop difference.

It'd be neat if you could run some experiments to determine what it was that she was drawn to.

Why would you think that crop sensors would improve but FF sensors
would not improve by the same amount? If anything, as FF sensors are
in Canon and Nikon's flagship DSLRs, the exact opposite, if anything,
would be true.

What I meant was that if I'm to decide if I should get the 5D now or some other camera, that other camera might have a next generation sensor that might have better noise characteristics.

I was looking at the 5D review and in this comparison, it is shown
that the 5D doesn't capture an image much differently than the D2x.
Where is the FF advantage here?

http://www.dpreview.com/reviews/CanonEOS5D/page29.asp

Oh man, I'm so glad you brought that up! It's DOF in action.

I must say that THIS was where I actually SAW a difference! You've just helped me achieve a new level or awareness! Thank you!

Note how the numbers on the bar at the top of the page are
sharper with the D2X shot, but softer on the 5D shot. Also, look how
blurred the bottom of the 5D pic is compared to the D2X pic.

I see it now! The flat subjects in the background are out of the DOF range of the 5D! Makes me wonder how many readers actually realized that and if any mistakenly thought they were less sharp because of some other reason other than DOF.

Now
look at the subjects of the photos -- all sharper with the 5D pic.

Why is that?

Do you now see why I say DOF is important?

Yes!

Man, pictures make it so much easier to understand. I'm a pictures and diagrams kind of a guy.

Now, on the other hand, just how big would you have to print for
anyone to care about this difference in sharpness?

I was looking at those pics on my laptop display (17" 1900x1200) and now I'm on a different computer (20" 1600x1200). I couldn't tell on my laptop, but I can on this computer.

I don't feel like doing the math to figure out the actual size of the print right now =)

Dude, it is so tiring responding to you with these long detailed
responses, but you are asking such freakin' good questions that it's
a real pleasure. : )

Hehe, thanks so much for helping me understand all this!

 

[Ominous]

a 35L is a 35mm lens. Not a 50mm something.
a 135L remains a great portrait lens.

That doesn't say anything...at all...to me. Besides, the 85 1.2 is
better. You want 35mm...just get a wider lens. If the desired lens
does not exist, then FF is for you.

The 85 1.2 on a FF camera has no equiv in the crop world.....neither does the 35 F1.4, 24 F1.4, 50 F1.2

same is true for the 17-40, 24-105L ( there is mo such lens for
cropped sensors now and this lens alone is worth FF )

Isn't that what the 10-22 is for?

16-35 F2.8? 14 L?

24-105...true..at least yet. Sony has a 16-80 though so we know it's
possible.

And that´s all without taking shallow DOF, noise or per pixel
sharpness into account.

So far all this talk about the above seems to be myths and
misunderstandings.

What lens will give the same DoF on a crop camera as what I can get on a FF camera with an 85 F1.2, 35 F1.4, 24 F1.4, 50 F1.2, 16-35 F2.8?

--
http://www.pbase.com/ewhalen

 

[Dan62326]

The 85 1.2 on a FF camera has no equiv in the crop world.....neither
does the 35 F1.4, 24 F1.4, 50 F1.2

50 for the 85
24 for the 35
35 for the 50

close enough

16-35 F2.8? 14 L?

true

What lens will give the same DoF on a crop camera as what I can get
on a FF camera with an 85 F1.2, 35 F1.4, 24 F1.4, 50 F1.2, 16-35 F2.8?

Why would you want shallow DOF from a 24mm lens? a 16-35? 35? Besides, it's just about a 1-stop difference. I can live with F1.2 on crop.

Anyway, you're comparing a lens system that is how many years old to one that has been around since...?

I think crop has been quite good and will only get better.

But you're right.

 

[Ominous]

The 85 1.2 on a FF camera has no equiv in the crop world.....neither
does the 35 F1.4, 24 F1.4, 50 F1.2

50 for the 85
24 for the 35
35 for the 50

close enough

DoF will be different.

16-35 F2.8? 14 L?

true

What lens will give the same DoF on a crop camera as what I can get
on a FF camera with an 85 F1.2, 35 F1.4, 24 F1.4, 50 F1.2, 16-35 F2.8?

Why would you want shallow DOF from a 24mm lens? a 16-35? 35?
Besides, it's just about a 1-stop difference. I can live with F1.2 on
crop.

Anyway, you're comparing a lens system that is how many years old to
one that has been around since...?

I think crop has been quite good and will only get better.

But you're right.

I don't care how new a system is when I have an image I want to take today.

--
http://www.pbase.com/ewhalen

 

[Amin Sabet]

The 85 is less sharp wide open because it is WIDE OPEN when wide
open. They're both about as sharp at F2. I'd rather have F1.2
available for available light photography.

I don't think the 85L at f/1.2 on a 1.6x body is significantly better for available light than the 135 at f/2 on a 35mm body. Light gathering ability is similar.

But I was just pointing out that there was a lens available for the
crop bodies that gives that angle of view.

No, what you said was "the 85 1.2 is better."

--
http://aminphoto.blogspot.com
http://aminsabet.tumblr.com

 

[Dan62326]

DoF will be different.

true...I'd love to see how different it would be though since it's just about a 1-stop difference

Why would you want shallow DOF from a 24mm lens? a 16-35? 35?
Besides, it's just about a 1-stop difference. I can live with F1.2 on
crop.

Your answer to that was great. Nice pics btw. How close were you to that boy!? =)

And speaking of pictures like that, did you just use the center AF point and did your camera ever focus on something other than what you wanted it to focus on? And what camera were you using?

I don't care how new a system is when I have an image I want to take
today.

That's one way to say it....you've made your point....for now.

 

[Ominous]

DoF will be different.

true...I'd love to see how different it would be though since it's
just about a 1-stop difference

Why would you want shallow DOF from a 24mm lens? a 16-35? 35?
Besides, it's just about a 1-stop difference. I can live with F1.2 on
crop.

Your answer to that was great. Nice pics btw. How close were you to
that boy!? =)

Pretty close. A 35 MM lens means you need to get rather close for a full face shot like that.

And speaking of pictures like that, did you just use the center AF
point and did your camera ever focus on something other than what you
wanted it to focus on? And what camera were you using?

Not sure on that shot, but when shooting at such large apertures I often use an off center point to avoid OOF due to focus and recomposing.

I don't care how new a system is when I have an image I want to take
today.

That's one way to say it....you've made your point....for now.

Til next time!!!! hehe

--
http://www.pbase.com/ewhalen

 

[Dan62326]

No, what you said was "the 85 1.2 is better."

I went back to see what I wrote and you're right. What I meant when I said that was that you could use F1.2 on the 85.

 

[Dan62326]

Pretty close. A 35 MM lens means you need to get rather close for a
full face shot like that.

How do you find time to switch to so many primes? Do you have other photographers covering stuff while you shoot these types of shots?

Not sure on that shot, but when shooting at such large apertures I
often use an off center point to avoid OOF due to focus and
recomposing.

I see. Were you using a 5D or a 1Ds?

 

[Dan62326]

I did even less testing than Ken, but I'll tell you my experience. I
went from a 30D to a 5D and immediately noticed that my lenses
performed better. They were sharper on the 5D. I didn't analyze the
corner performance because the overall improvement was apparent
enough. I don't know if the 5D shines because of a low AA filter or
because of big pixels, but it was a clear step up for me.

Did you notice a change in DOF?

I also
feel that Capture One 3.x brings out the best in Canon DSLR files,
particularly those from the 5D.

How would you rate the 5D out-of-camera JPG's to your capture one files?

 

[Radio Denver]

There is no difference between the 30D and the 5D depth of field, if you are standing in the same spot, shooting the same scene with the same lens at the same aperture. It gets confusing and a lot of folks think there is a difference. Just think of the 30D as having the outer 3rd of the image chopped off (crop) What makes a difference is when you move in or out with either camera to approximate the same field of view as the other camera.

The JPG's out of the 5D look okay enough, but personally I don't shoot JPG very much. The converted raw files are excellent though.

I did even less testing than Ken, but I'll tell you my experience. I
went from a 30D to a 5D and immediately noticed that my lenses
performed better. They were sharper on the 5D. I didn't analyze the
corner performance because the overall improvement was apparent
enough. I don't know if the 5D shines because of a low AA filter or
because of big pixels, but it was a clear step up for me.

Did you notice a change in DOF?

I also
feel that Capture One 3.x brings out the best in Canon DSLR files,
particularly those from the 5D.

How would you rate the 5D out-of-camera JPG's to your capture one files?

--
Visit me at

http://www.have-camera-will-travel.com

 

[Ominous]

Pretty close. A 35 MM lens means you need to get rather close for a
full face shot like that.

How do you find time to switch to so many primes? Do you have other
photographers covering stuff while you shoot these types of shots?

2 camera bodies...and perhaps someone else with a zoom.

Not sure on that shot, but when shooting at such large apertures I
often use an off center point to avoid OOF due to focus and
recomposing.

I see. Were you using a 5D or a 1Ds?

5D

--
http://www.pbase.com/ewhalen

 

[Amin Sabet]

Did you notice a change in DOF?

I did. Using the Sigma 30 on a 30D could not give me as shallow a DOF as using the Canon 50 at f/1.4 on a 5D, for example, at a given output size, field of view, and perspective.

I also
feel that Capture One 3.x brings out the best in Canon DSLR files,
particularly those from the 5D.

How would you rate the 5D out-of-camera JPG's to your capture one files? I almost never shoot JPEGs with the 5D. C1 gives me better detail/noise and color.

--
http://aminphoto.blogspot.com
http://aminsabet.tumblr.com

 

[Amin Sabet]

No, what you said was "the 85 1.2 is better."

I went back to see what I wrote and you're right. What I meant when I
said that was that you could use F1.2 on the 85.

I too went back and had a look at some samples from the 85L on the 30D and 135L on the 5D. In fact, I believe the 85L may render nicer bokeh when DOF, perspective, and FOV are the same. I put one example in a blog post today. It's very limited, but you might find it interesting -> http://aminphoto.blogspot.com/2007/12/canon-lenses-on-full-frame-vs-crop.html

 

[Dan62326]

There is no difference between the 30D and the 5D depth of field, if
you are standing in the same spot, shooting the same scene with the
same lens at the same aperture.

Why would one do this? If you shoot the scene that way, either the 5D image will be too wide or the 30D's image will not cover the entire scene.

It gets confusing and a lot of folks
think there is a difference.

What's confusing other people is what you're saying. There is in fact a difference in DOF, but you make it sound like there isn't.

Just think of the 30D as having the
outer 3rd of the image chopped off (crop) What makes a difference is
when you move in or out with either camera to approximate the same
field of view as the other camera.

And of course you're going to do this. If my tripod is a certain distance from the subject and I switch from a 30D to a 5D using the same focal length, you bet I'm going to move the camera so that the subject correctly fills the frame.

 

[Dan62326]

So what did you mean when you said that the bokeh was a wash on the 85?

I too went back and had a look at some samples from the 85L on the
30D and 135L on the 5D. In fact, I believe the 85L may render nicer
bokeh when DOF, perspective, and FOV are the same.

 

[emorphien]

Ken is a great blogger, he says a lot of absurd things with a scattering of factual information in a format that people fall for. But if you really read a lot of what he has to say, it's largely useless.

--
If it makes sense, its probably never going to be done.