How to differentiate crop vs. FF

[Lee Jay]

It's still mainly overall cost. You're correct that using the same lens for a distant subject, more VF magnification and more AF points on subject are an advantage. But unless you're already at 1200mm (600 II + 2xIII), you're still talking cost savings. 600/4 on FF will beat 400/5.6 on APS-C.

It's more complex if you need a zoom lens. A 100-400 will be better (for resolving power) on a 7D than on a 5D, and a longer option is either crazy expensive and narrow in range (200-400/4) or just becoming available from third parties (150-600s).

On the other hand, if someone prefers wider DOF...will find more advantages in APS-C.

There's an exception, in that if your lens is stopped down to its narrowest aperture, APS-C gives deeper DoF because you can't stop the lens down further. But by then, diffraction will be softening the images a fair bit, and that will be worse on APS-C at typical pixel densities, so in that case you're trading sharpness for DoF.

Because of that diffraction, there is another option - a wider framing. Moving back or zooming out will get you DOF without costing you resolving power because diffraction has eaten it all anyway.

 

[hsbn]

There's one big advantage of full-frame that a lot of people don't recognize - the variety of zoom lenses starting at 24mm.

Full frame:
24-105/4L IS
24-70/4L IS
24-70/2.8 II
Tamron 24-70/2.8 VC
Sigma 24-70/2.8
Sigma 24-105/4 OS

Crop:
15-85/3.5-5.6 IS

You can use all of those lens on CROP too. It will change the field of view but it doesn't change the lens quality. Actually, you can even say that "There's one big advantage of CROP that a lot of people don't recognize - the variety of zoom lenses starting at 10mm"

 

[Loswr]

There's one big advantage of full-frame that a lot of people don't recognize - the variety of zoom lenses starting at 24mm.

Full frame:
24-105/4L IS
24-70/4L IS
24-70/2.8 II
Tamron 24-70/2.8 VC
Sigma 24-70/2.8
Sigma 24-105/4 OS

Crop:
15-85/3.5-5.6 IS

You can use all of those lens on CROP too. It will change the field of view but it doesn't change the lens quality. Actually, you can even say that "There's one big advantage of CROP that a lot of people don't recognize - the variety of zoom lenses starting at 10mm"

Well, 10mm on APS-C is 16mm on FF, and there's a good variety of 16-xx zooms for FF.

The point is that 24-xx is a general purpose' zoom lens that covers wide angle to short tele. Still, while the difference between 24mm and 28mm is significant, there is a plethora of 17/18-xx zooms for APS-C.

 

[V8Beast]

I find the tonal range of FF images to be substantially better than those captured with a crop sensor. That said, I almost never recommend FF over a crop body for those seeking the most value per dollar.

 

[dak723]

Based on my experience, FF advantages are: better IQ, better in low-light, less DOF (when you want it), larger viewfinder. Advantages of Crop: more reach, more DOF (when you want it), uses the center (and better) part of lens, thus less vignetting, CA, distortion and overall sharpness. Much of the latter can be corrected on both FF and Crop, so may not be an issue.

 

[Loswr]

Advantages of Crop: ...uses the center (and better) part of lens, thus less vignetting, CA, distortion and overall sharpness.

Vignetting and distortion, yes. CA depends on the type (axial vs. lateral), and can be worse (the typically higher pixel density on crop means CA from the lens covers more pixels). As for 'overall sharpness', assuming you're framing the same with both, the FF wins hands down. Pick a lens and compare FF with APS-C on TDP's ISO 12233 crops, the difference in sharpness is substantial.

 

[YuengLinger]

Budget is the only reason to go with cropped.

Except maybe for the amazingly spec'd 7DII.

 

[LesC]

I think the difference between FF & crop IQ wise is not always that great - quality of the lens used is more important but there's a reason why most Pros use FF. And if money was no object, who wouldn't go FF

 

[FTb-n]

FF Advantaged:

- Better low light/high ISO performance
- Greater color depth
- Narrower DOF, which means better control of DOF
- Generally speaking, features in demand by pros more likely in FF (the 7D2 may buck the tide a bit on this)
- Sharper images given EF glass. This one surprised me. Check out the comparison of a 70-200 f2.8L II on a 1Ds Mk3 vs. a 60D
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&FLI=0&API=0&LensComp=687&Sample=0&SampleComp=0&CameraComp=736&FLIComp=0&APIComp=0
- Strengthens muscles if carried for 20 minutes every day.
- Simplifies one's bank account

 

[jdramirez]

A minor point, but one I think is worth mentioning, is the larger viewfinder with FF. I find it makes it easier to compose with and is just generally nice to have.

Obviously this becomes a moot point when referring to mirror-less cameras.

I was passing with a t1i the other day and the smaller viewfinder was killing me.

 

[dtaylor]

FF has less noise and retains more detail at higher ISOs. Given similar sensor tech levels it seems to be a good 2 stop advantage, sometimes a bit more.

There are lenses which do not have good crop equivalents. Canon's fast wide primes and T/S lenses are good examples, though this isn't a given (i.e. someone could make crop equivalents if they wanted).

In theory FF should have more DR (higher full well capacity) but Imatest testing doesn't always bear that out.

Crop gives you a built in 1.6x teleconverter with practically no downsides. Though, as others have pointed out, with the resolution of modern sensors this advantage is slim. For most subject/print size combinations you can just crop the center out of a FF file and have hardly any difference. The advantage now seems to be mostly in the viewfinder view.

Crop is cheaper, and some lenses are cheaper for the FoV and IQ because they're easier to manufacture for crop.

I know I'll get arguments on this, but...at ISOs where noise is effectively a "solved problem", and when all other factors are equal, there are no real IQ benefits to FF after processing. FF images are sharper OOC but the difference is well within the range of software (in camera or out) to correct. Human psychology being what it is people will claim to see differences when the labels are there and get totally lost when the labels are gone. I might say that you can still sometimes see a difference while pixel peeping...though that might be my own psychology at work...but in print it's completely lost.

I've tested this more times then I have wanted to when friends have challenged me on it, using both online test samples and in the field shots we have made. Even I am sometimes surprised at how much difference must exist before it's obvious to the human eye in print.

In the most recent test a friend and I downloaded the Imaging Resource ISO 100 RAWs for the A7R, A7, 5D3, and 70D. We converted using optimum ACR settings for each (noise and detail); scaled everything to the A7R dimensions; then applied sharpening in PS to try to optimize three of them (the A7R is pretty much optimal from the RAW converter in this respect). Next we took strips and made a 4-Up print at 200 ppi, roughly the same as a 24x36" print.

My friend predicted we would easily see the differences between all four. I predicted A7R and 70D would be obvious but not the A7/5D3. The first print showed no advantage any where. At all. Even I was surprised that with my nose on the print, no advantage could be seen any where.

For the second our strips included the chart with small type on the far right. In that print we could see a difference in the rendering of the smallest type and it followed my prediction, but no difference any where else. Whether or not that difference would ever be seen by someone who wasn't looking for it is another question entirely. It was exceedingly small, a difference in the quality of the rendering, and only on the tiny type.

We're going to try again at some point in the field with three of the cameras, but I suspect the results will not change.

 

[kphoto99]

One advantage of crop is that after buying the camera body you will have more money left over to but an excellent lens. The higher quality lens will have more effect on the quality of the image then the camera

 

[candc]

the key is under what conditions? using normal apertures under normal light there is really not much difference. i have done some comparison testing myself and found that to be true. ken rockwell says there is not much difference between the sl1 kit and the 5dii + 24-70ii. that's inflammatory hogwash right? not really.

http://kenrockwell.com/canon/comparisons/sl1-vs-5d-mk-iii/

that's not to say the sl1 combo is just as good as the 5diii one but in that example he is right.

how about this for a more extreme comparison.

http://petapixel.com/2014/10/02/zeiss-otus-85mm-f1-4-vs-two-year-old-pocket-camera/

i have seen your sample pics with the new lens and am really impressed. you know how to use it to its full advantage where nothing else compares but with medium apertures in normal light viewed at normal size? all the modern cameras even the cheapest do a good job.

i bought a 6d for using in low light where it is really much better than the crop cameras. you can use pretty high iso with the crop cameras in good light to get your shutter speed up but if the light is bad ff is the way to go.

also as everyone knows if you want that super shallow dof then you want a ff camera for it.

 

[sdsr]

One advantage of crop is that after buying the camera body you will have more money left over to but an excellent lens. The higher quality lens will have more effect on the quality of the image then the camera

Perhaps, but as a general rule, as Neuro and others have pointed out, any given lens (assuming you can attach it to both) generates better images on a FF body than it does on an APS-C body; I think it would be a shame to buy an excellent lens (let alone all the high-end lenses listed by the OP) and then restrict yourself to using it on an APS-C body.

(One could, in fact, make the opposite argument - that owning a FF body allows you to save money on lenses, at least in some circumstances (there's no FF equivalent to the remarkably cheap Canon 10-18mm, for instance), sometimes astonishingly so - there are some ridiculously cheap old manual prime lenses that make amazingly good photos when attached to a mirrorless FF body (perhaps they do on dslrs too, but mirrorless bodies make it incomparably easier to use such lenses). E.g. while everyone else has been getting worked up over the Sigma 50mm Art (which I'm sure is wonderful), I've been greatly enjoying using, on my Sony a7r, a Pentax/Super-Tak 50mm 1.4 (c. $90), a Minolta/Rokkor X 50mm 1.4 (c. $50) and a Nikkor 55mm 2.8 macro (but superb even at infinity - c. $100); but then I don't shoot sports, BIF etc....)

Anyway, in terms of sheer image quality, other things being equal, FF wins, for the reasons given by others (Sporgon's point is especially good). I have a couple of APS-C bodies, but I'm really not sure why. That said, whether the differences are of any significance, or are even noticeable at all, is another matter. It all rather depends on how the resulting images are viewed and how critical the viewer is (the same goes for differences in image quality among lenses, for that matter), and an APS-C body may make more sense for reasons unrelated to sheer image quality.

For me, the issue gets more interesting if you throw M43 into the mix, because that system, unlike APS-C, provides a big advantage over FF in terms of weight/bulk while providing image quality that rivals APS-C, albeit with a loss of shallowness of focus (plus, it tends to cost more than APS-C dslrs). Of course, it can't compare to FF at high ISOs (it's not much different from APS-C), but if you're not trying to freeze action, that's not an issue - thanks to the extremely effective IBIS in more recent Olympus M43 bodies (E-M5 and later), I have little difficulty in keeping the ISO at 200 most of the time, and, of course, since it's IBIS it applies to any lens you attach.

So there may not be an easy answer....

 

[FTb-n]

Interesting thread so far. My jump to FF wasn't that long ago. I still use my 7D, but in comparison, the 5D3 images have more pop to them. That's part of the key. After getting the shot, it is easier to see the difference between FF and crop when comparing two similar photos side-by-side. However, good crop bodies with good glass can produce great images that can be hard to discern from FF when there's no side-by-side comparison.

Every body has boundaries where getting the shot and image quality is challenged. For me, the FF 5D3 was a better choice when I realized that I pushing my crop 7D beyond these boundaries. That's the biggest difference. If you live within the sweet spot of a crop body, the advantages of a FF body are minor.

 

[dtaylor]

Perhaps, but as a general rule, as Neuro and others have pointed out, any given lens (assuming you can attach it to both) generates better images on a FF body than it does on an APS-C body;

Eh...it produces sharper images OOC and often images with more local contrast, but unless noise is a factor (higher ISOs) it's trivial to match this in post.

there are some ridiculously cheap old manual prime lenses that make amazingly good photos when attached to a mirrorless FF body (perhaps they do on dslrs too, but mirrorless bodies make it incomparably easier to use such lenses).

They generally do the same when attached to a crop body.

Anyway, in terms of sheer image quality, other things being equal, FF wins, for the reasons given by others (Sporgon's point is especially good).

At lower ISOs it's a wash. I've often said this, but my last FF vs. crop / higher MP vs. lower MP print test stunned even me, and silenced a friend who loved to debate this.

In fairness, it's a wash after post processing. But the differences are simply not that large to begin with.

 

[Helios68]

Pro FF:
+DR
+DoF
+Better high ISO performance (pixels are 2x larger on 5D Mkiii than on 70D for example)

Pro APS-C
+much cheaper in general

Crop factor 1.6x is not really an advantage. If your take just the center of the 5D Mkiii frame you get ~9.4MP which is enough to print A2 pictures without quality loss. But on the other side in good like conditions you can crop the image form an APS-C sensor too.

This brings me the following question. For wildlife which is better? APS-C or FF?

 

[sandymandy]

Well i love wide angle so APS-C is really not my kind. Wide Aperture + wide lense doesnt match a small sensor

 

[Lee Jay]

Pro FF:
+DR
+DoF
+Better high ISO performance (pixels are 2x larger on 5D Mkiii than on 70D for example)

Pro APS-C
+much cheaper in general

Crop factor 1.6x is not really an advantage. If your take just the center of the 5D Mkiii frame you get ~9.4MP which is enough to print A2 pictures without quality loss. But on the other side in good like conditions you can crop the image form an APS-C sensor too.

This brings me the following question. For wildlife which is better? APS-C or FF?

And when I want the center 30% of an APSc frame?

Crop wins for focal length limited situations.

 

[Helios68]

Pro FF:
+DR
+DoF
+Better high ISO performance (pixels are 2x larger on 5D Mkiii than on 70D for example)

Pro APS-C
+much cheaper in general

Crop factor 1.6x is not really an advantage. If your take just the center of the 5D Mkiii frame you get ~9.4MP which is enough to print A2 pictures without quality loss. But on the other side in good like conditions you can crop the image form an APS-C sensor too.

This brings me the following question. For wildlife which is better? APS-C or FF?

And when I want the center 30% of an APSc frame?

Crop wins for focal length limited situations.

Right but just when light is sufficient. And if you take the 30% in the middle even with a 22MP you will get a 2MP picture... which is quite small. Maybe you should have done something wrong with the focal length you choose...