[stevebrot]

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I do not want to hear an analogy that EMACS = FF and vim = aps-c. That would be a horrible analogy. (no-one should ever need anything more than vi, BTW.)


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EMACS = Masochism


Steve

(not particularly fond of vi, but terrified of EMACS......and I operate in that world for a living!)

[Emacs]

vi sucks

[stevebrot]

...
I hate comparison test shooting, but here's one image combo that gives you an idea of what you would start to notice (slight framing difference, same distance to subject though) :

35mm f/2.8 on aps-c, 50mm f/2.8 on FF


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There you go. One of the strongest arguments is about image isolation (pop from background). There was a recent post with video on the Medium Format section regarding shooting sports (snowboarding to be specific) with a 645d. The pro who was doing the shot made a strong point that the bulkier camera was worth it because the larger format allowed for better subject isolation at the working distances and framing that are typical for that type of shooting. Translation: He could not get the look he wanted from either APS-C or FF digital.

This rational is not immediately apparent to the newb and may not even be obvious to an experienced photographer. It all depends on the needs for your style of shooting and your experience with formats beyond APS-C. There is a reason why APS-C was sort of a flop when it was introduced for film and it was only partially related to larger grain. It might also be noted that wide-scale acceptance of 35mm over larger formats took several decades due to issues similar to those commonly raised in regards to APS-C. Eventually the benefits of convenience and compact kit along with introduction of faster lenses and better emulsions shifted general usage in favor of what were then termed "miniature" format cameras.


Steve

[DAZ]

To have a rational/logical discussion of the differences between formats it is advisable to understand and use the concept of equivalency. If one doesn’t understand and use the concept of equivalency the discussion inevitably descends into an anecdotal war of blind men describing an elephant. I.e. “they need to be blown up less in cropped sensor to achieve same size subject in a 8x10 print”. There is enough overlap between APS-C and 135 that if you hold all parameters equivalent you can produce an 8x10 print that is for practical purposes indistinguishable. Only near the edge of the syntax can one start to see the true differences.

Equivalency will not tell you what is the better format only help you understand the differences. When you understand the differences you can then apply the concept of “good enough” (the world for the most part is controlled by the concept of good enough) and make a judgment from the point of view of the buyer on what is “better”. Less DOF could be a good thing or a bad thing. The cost difference to the performance difference could be insignificant or the key difference. This applies from the smallest to the largest formats.

A lot more money is being made with some of the smallest formats even though it could be argued that the smaller formats may not produce the best technical photos. Because so much is being made with the smaller formats (and they can be helped the most) the smaller formats are getting the newest technology first. The makes it harder to use equivalency when comparing APS-C to 135 for example. If all parameters are held equivalent then there should be approximately 1.3 stops of noise (or DR) between the 2 formats. But because of the economics the APS-C is getting the technology before the 135 that ATT APS-C is pulling ahead 1-2 generations technology ahead of 135. This means that if one is looking to see the difference in performance you have to use an older APS-C to a new 135. If you use both new 135 and APS-C the APS-C will be about the same or a little better do to the technology not the difference inherent in the formats. So one of the things you must hold equivalent is the technology.

Because of the economics/“good enough” larger formats will continue to be more and more marginalized. There may be a time in the near future when even the APS-C format may become a small niche like large format film was. As economics/“good enough” squeeze more the intermediate steps will start to be squeezed out. This could mean that the 135 format between the APS-C that sells a lot and the new digital MF formats with the better technical photos could be what gets squeezed.

DAZ

[stevebrot]

When you understand the differences you can then apply the concept of “good enough” (the world for the most part is controlled by the concept of good enough) and make a judgment from the point of view of the buyer on what is “better”.

There is a saying in quality improvement circles:

"The ultimate enemy of good is better..."

I agree totally regarding the ultimate squeeze-out of the current FF digital by cameras such as the 645d and the Leica S. Unless FF digital bodies can be made in a more compact form to match the optics they support, they are pretty much doomed.


Steve

[normhead]

Thanks jsherman, a noticeable difference, which I expected, better DoF on the APS-C which I expected, In this case, I actually like the APS-C better, although there could also instances where I'd like the FF better as well. I went through the same thing with a Panasonic point and shoot and 35 (K1000) mm film cameras, really tough to get a nice bokeh with a point and shoot. My students really had to work on it. It's much easier on the film cameras (FF).

On another note..
How come you didn't get the kid to look at the camera in both pictures.. just kidding. Man I hate pictures of snow this time of year... I'll come back and look again in the summer, when it's 90 degrees.

[JohnBee]

35mm f/2.8 on aps-c, 50mm f/2.8 on FF.

Looks interesting...
Any chance of seeing 50mm from both in the same scene?
I'd be curious to see the FOV and OOF differences toe to toe.

[DAZ]

.35mm f/2.8 on aps-c, 50mm f/2.8 on FF.

Although interesting not equivalent. There should also be an aperture difference.

DAZ

[stevebrot]

Although interesting not equivalent. There should also be an aperture difference.

DAZ

That is the point. It is not possible to get reasonable equivalence.



Steve

[stevebrot]

Looks interesting...
Any chance of seeing 50mm from both in the same scene?
I'd be curious to see the FOV and OOF differences toe to toe.

To do the same focal length with the same framing would require either different camera position (resulting in different perspective) or cropping of the FF image. The FF image would then be equivalent to the APS-C image. Unfortunately, there is no way to work the magic the other way around.


Steve


(Went through this whole business about three years ago on the whole issue of perspective, DOF, focal length, etc with multiple comparison shots, though to be fair, the thread was not about FF vs. APS-C.)

[normhead]

Is there really a difference in FoV? Wouldn't you just have more magnification in your viewfinder to produce the same FoV? With magnification you should be able to have whatever size view you want.

There should also be an aperture difference.

I understand why you might say that, but I don't agree. I want to see them both at the same aperture. Compensating for better DoF on an APS-C so that it doesn't have better DoF but has a wider aperture, I'm sure you can make both images look the same but why? Once you change the aperture, now you're in to changing shutter speeds or ISO , possibly changing the amount of light available to the sensor, creating issues of reciprocity and therefore noise. If I'm designing this test, I'd use do it the way jsherman did, approximately the same focal effective length and the same aperture.

What would be the point in changing the DoF so they were the same if the difference in aperture meant there would be shots you could take with the APS-C that you couldn't even take with the FF because of low light?

[MPrince]

Sometimes it really annoys me, after these people insist there is no significant difference besides DOF between FF and APS-C, but then they do find 645D images much better than FF, although objectively that difference isn't near as large as between first two.

I don't even mention superior viewfinder, which really helps to choose better moments (for me, at least).

I don't generally read posts about FF, since Pentax has stated they have no plans to introduce one, but I was wondering if you would be kind enough to provide the name of one person on this forum (along with a link to the thread) who has made the above statement? I'd be interested in seeing the context in which the statement was made. Thanks so much.

[DAZ]

That is the point. It is not possible to get reasonable equivalence.
Steve

To get an equivalent photo you start by taking the photo from the same place. This keeps the same POV. Then you change the lens length to maintain the FOV. Next you change the aperture (for APS-C to 135) 1.3 stops. You would then have to compensate ISO or shutter speed. When you have all of this then (assuming the lenses and sensors have the same resolution) you will have an equivalent photo. It should look the same. What would be deferent is the DR but only if you exceeded the DR in only one of the photos or an increase in noise but only if the dark parts of the photo are below the noise. With the photo in question both DR and noise should not be visible. You could also possibly see motion blur from a shutter speed difference but again not in this photo. Where the problem could arise is at the edge of the syntax. Getting a lens for the APS-C system that has a small enough aperture in a wide lens. This is where there is an edge to the APS-C syntax but yet again not in this photo.

DAZ

[jsherman999]

Looks interesting...
Any chance of seeing 50mm from both in the same scene?
I'd be curious to see the FOV and OOF differences toe to toe.

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50mm from both cameras, taken from the same position and the same aperture? aps-c shot would have much less FOV and less DOF.

I always whip out Bob Atkins' excellent years-old summary in situations like this - understand these bullet points and you get it all (your question is answered in what I bolded.)


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• For an equivalent field of view, an APS-C crop sensor camera has at least 1.5x MORE depth of field that a 35mm full frame camera would have - when the focus distance is significantly less then the hyperfocal distance (but the 35mm format needs a lens with 1.5x the focal length to give the same view).

• Using the same lens on a APS-C crop sensor camera and a 35mm full frame body, the a APS-C crop sensor camera image has 1.5x LESS depth of field than the 35mm image would have (but they would be different images of course since the field of view would be different)

• If you use the same lens on a APS-C crop sensor camera and a 35mm full frame body and crop the full frame 35mm image to give the same view as the APS-C crop image, the depth of field is IDENTICAL

• If you use the same lens on a APS-C crop sensor camera and a 35mm full frame body, then shoot from different distances so that the view is the same, the APS-C crop sensor camera image will have 1.5x MORE DOF then the full frame image.

• Close to the hyperfocal distance, the APS-C crop sensor camera has a much more than 1.5x the DOF of a 35mm full frame camera. The hyperfocal distance of a APS-C crop sensor camera is 1.5x less than that of a 35mm full frame camera when used with a lens giving the same field of view.



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[rhodopsin]

Actually no. If you're looking at percent of the frame, yes but that is not actually how you measure DOF.

Its often misunderstood or mis-represented, but film/sensor size is not an aspect that affects DOF.

Crop sensor does just that... it crops.
Naturally, getting in closer to the in-focus area around the plane of focus will make the DOF appear larger within the frame... but in reality the same amount of the subject will be in focus.

Well, when talking about circles of confusion... sure there is a difference almost insignificantly and impreceptively... certainly not enough to cause someone to go from crop to FF to get a different DOF like most people talk about.

First case cameras equal distance from subject, correct, DOF does not change with sensor size.

Second case cameras framing identical, i.e. larger format sensor is closer, then distance is less, DOF decreases.

Larger sensor is capable of smaller DOF than smaller sensor, given identical framing -- THIS is the primary advantage of FF over APS-C, of any larger format over any smaller format.

"Its often misunderstood or mis-represented" -- Wow that can be said again and again over and over ad nauseum...