Crop sensors better than full frame for macro photography?

[philmoz]

I agree, for macro photography, a crop sensor has the edge. Unless of course, you're a fan of focus stacking 10 or more images...which I'm not. A full frame sensor necessarily requires more focus stacking, unless you want your macro images with shallow depth of field...in which case either FF or crop are ok for that. I don't profess to be a macro expert, though...but I do know that a macro image I shot with an effective 270mm focal length at f/20 on a crop camera, would have needed to be at f/45 or smaller on a full frame sensor, and would have provided 1.6x less magnification to boot.

I'm not a macro expert here; but I think you're mistaken here.

I may be interpreting things incorrectly, or have the math wrong - apologies in advance if this is the case

My understanding is that for macro photography the DoF calculation is different and the lens focal length does not play a factor - only the aperture, sensor circle of confusion and image magnification are important.
See http://en.wikipedia.org/wiki/Depth_of_field (Close Up section).

By image magnification I mean the size of the object being photographed on the sensor compared to it's size in real life. So for 1:1 magnification a 1cm square object will occupy 1cm square on the sensor regardless of the camera sensor size.

The circle of confusion on the FF camera is 0.029mm and on the APS-C camera it is 0.018mm.
http://en.wikipedia.org/wiki/Circle_of_confusion

If magnification and aperture are the same then the FF sensor has a DoF that is 1.6 times larger than the APS-C camera (0.029 / 0.018).

Obviously the two cameras are capturing different images. At 1:1 magnification the FF camera is capturing a 36mm x 24mm area of the subject, while the APS-C only captures a 14.8mm x 22.2mm area of the subject.

You could get similar DoF on the APS-C camera by decreasing aperture by 1 1/3 stops, which would require a corresponding increase of ISO or shutter speed to compensate the exposure.

I would guess that most macro photographers want to maximise the size of their subject on the sensor to get the best image possible

In order to capture the same subject size relative to the sensor size we need to change the magnification for one of the cameras. For example if the subject fills the APS-C frame at 1:1 then we need to shoot at 1.6:1 on the FF camera in order to expand the subject to fill the frame. Conversely if the subject fills the FF sensor we need to reduce magnification to 1:1.6 on the APS-C camera in order to capture the whole subject without cutting off any parts.

Increasing the magnification on the FF camera to 1.6:1 will roughly halve its DoF.
Decreasing the magnification on the APS-C camera to 1:1.6 will roughly double its DoF.
In both cases the APS-C camera will now have more DoF than the FF camera by a factor of approximately 1.25.

Of course we can now decrease the aperture on the FF camera by 1 stop and it will again have slightly greater DoF than the APS-C camera.

In summary:
- At the same magnification the FF camera has 1.6 times more DoF than the APS-C camera
- If the subject fills the same percentage of the sensor then the APS-C has the DoF advantage by a factor of 1.25. A 1 stop decrease in aperture gives the advantage back to the FF camera.

Phil.

 

[Northstar]

Hopefully this is helpful for some folks following this discussion.

When using the exact same:

1. Focal length
2. Aperture
3. Distance to target

The following two images show what happens to the depth of field when using a crop vs a FF camera. I've compared a 5d3 with a 7D. Note that the crop camera has a shallower depth of field

For anyone following this post that wants to learn more about depth of field and how it changes with different apertures, distances, and focal lengths, then go play around with the following website. (Neuro referenced it earlier)

http://www.dofmaster.com/dofjs.html

 

[SambalOelek]

I have spent quite some time trying to find the best camera for macrophotography (handheld, >1:1 magnification). This is similar to being reach limited in conventional photography.

The 60D is a joy to use for this kind of photography, because of the articulated screen and the built-in Speedlite transmitter. On the other hand, using a large, clear (read: full frame) viewfinder makes the camera more stable.

I personally found that the "reach"/pixels on target advantage of APS-C didn't result in better overall image quality, because of the noise creeping in at low/moderate ISOs. But it does come close at ISO 400 or lower. In my opinion, the 60D/7D outperform the 5D Mark II, but not the Mark III.

The 1D Mark IV with its medium-density APS-H sensor performs really well, but loses out to the 5D Mark III at higher ISOs. The aging 1Ds Mark III is a joy to use, with its fantastic viewfinder, but noise starts to creep in really quickly, and the LCD is useless to determine sharpness at the pixel level.

Overall, the 1D X and 6D deliver the best quality, with the weak spot of the 6D being its viewfinder. Obviously, Wi-Fi is not that useful for handheld macro.

Best image quality:

• 1D X, 6D
• 5D Mark III
• 1D Mark IV
• 60D, 7D
• 5D Mark II
• 1Ds Mark III

 

[Marsu42]

When using the exact same:
1. Focal length
2. Aperture
3. Distance to target

Thanks, but I suspect most of us know about that, but just to recapitulate and not enter any mudslinging again the issue at hand is:

* same focal lengths just for the sake of discussion, but the different working distance for live critters is an issue

* not the same distance to target to have the same framing (I'd like the butterfly to fill my frame, no matter the sensor size). Given the specifics of a macro lens, this might also mean the effective f-stop differs even more than at standard distances.

* not the same aperture to reach a comparable dof, resulting in an iso shift

Overall, the 1D X and 6D deliver the best quality, with the weak spot of the 6D being its viewfinder

Um, what's wrong with the 6d vf? I've never come near a 1dx, so I cannot tell the difference and what you might refer to.

 

[Northstar]

When using the exact same:
1. Focal length
2. Aperture
3. Distance to target

Thanks, but I suspect most of us know about that, but just to recapitulate and not enter any mudslinging again the issue at hand is:

* same focal lengths just for the sake of discussion, but the different working distance for live critters is an issue

* not the same distance to target to have the same framing (I'd like the butterfly to fill my frame, no matter the sensor size). Given the specifics of a macro lens, this might also mean the effective f-stop differs even more than at standard distances.

* not the same aperture to reach a comparable dof, resulting in an iso shift

Overall, the 1D X and 6D deliver the best quality, with the weak spot of the 6D being its viewfinder

Um, what's wrong with the 6d vf? I've never come near a 1dx, so I cannot tell the difference and what you might refer to.

Marsu...I think you're right that many know about it, but I also think many don't and/or don't know it well enough. It's an incredible learning tool/website for those that don't, or want to learn more....which is why I posted.

It's much easier to learn about DOF when you manipulate the variables on a calculator and see actual results versus reading about the subject. And for macro work, DOF knowledge is critical.

As to the OP's original question, I think with good light it doesn't matter so much, but if you have golden hour light and need to work with higher ISO values then I would much rather have the FF.

 

[Marsu42]

Marsu...I think you're right that many know about it, but I also think many don't and/or don't know it well enough. It's an incredible learning tool/website for those that don't, or want to learn more....which is why I posted.

I didn't want to criticize, on the contrary, posting standard links now and again is a good idea since old threads obviously seldom get read ... speaking of which and concerning 1dx/6d/60 & ff/crop, I didn't post this link for some weeks now :->

Pro DSLR + Cheapo Lens vs "Cheapo" DSLR + Pro Lens

 

[SambalOelek]

Overall, the 1D X
and 6D deliver the best quality, with the weak spot of the 6D being its viewfinder

Um, what's wrong with the 6d vf? I've never come near a 1dx, so I cannot tell the difference and what you might refer to.

There is nothing inherently wrong with the 6D viewfinder, but the 1D X has a significantly larger image. The specs are 0.76x vs. 0x71x magnification, and ~97% vs. ~100% coverage, respectively. I think those numbers do not really tell the whole story, it is really a big difference. When trying to manually focus at macro distances, you want as good a viewfinder as possible.

On the other hand, someone coming from a xxxD would be blown away by the large, bright viewfinder of the 6D. It is a pity that Canon does not put 100% viewfinders in their entry-level cameras, as the optical viewfinder should be one of the main selling points of DSLRs these days. Even the cheapest Pentax DSLR has a viewfinder comparable to the 7D. But I digress..

 

[Northstar]

Marsu...I think you're right that many know about it, but I also think many don't and/or don't know it well enough. It's an incredible learning tool/website for those that don't, or want to learn more....which is why I posted.

I didn't want to criticize, on the contrary, posting standard links now and again is a good idea since old threads obviously seldom get read ... speaking of which and concerning 1dx/6d/60 & ff/crop, I didn't post this link for some weeks now :->

Pro DSLR + Cheapo Lens vs "Cheapo" DSLR + Pro Lens

No offense taken.

I've seen that video, I think Kai does some funny stuff from time to time...rather hit or miss though. I just noticed he posted a new video on how to shoot nude portraits that I'm sure some would enjoy....for learning purposes of course.

 

[Marsu42]

It is a pity that Canon does not put 100% viewfinders in their entry-level cameras, as the optical viewfinder should be one of the main selling points of DSLRs these days.

Even if I'll get flamed down (again) I'd like to mention I don't even want a 100% vf ... as I don't do stock photography where I'd need to sell the whole raw image, a bit of a safety margin is nice to have. I do agree about the magnification though, my good ol' film eos 620 has a *much* better vf than the modern and expensive 6d :-(

I've seen that video, I think Kai does some funny stuff from time to time...rather hit or miss though.

Actually this is the only video I like because he's very authentic as Mr. Ape with a "real man's camera" ... but I don't think his reviews are very useful, and certainly not his random camera/lens destruction. To me, he just seems to be a guy with too much time and money on his hands.

 

[dak723]

Though perhaps not strictly considered macro photography, I do a lot of photography of flowers. For many years I owned a crop camera (Original Rebel) and took many photos of flowers at distances of 2 to 3 feet on average. Since flowers aren't flat, having enough DOF to get a good percentage of the flower in focus is important - perhaps a DOF of an inch or so. This meant shooting at around f/11 with my Canon 100mm Macro (non-L) lens. Going to full frame and wanting to frame my photos the same, it becomes almost impossible to get the photo with a similar DOF. Again, this is trying to frame the photo the same - not crop - thus moving the camera closer to get the same shot and an adequate DOF. With the FF camera and the same lens, I now need to shoot at about f/20 to get the same DOF. Needless to say, if I need more than an inch of DOF, the lens apertures don't go high enough when using the FF camera. So, I don't know which is better - crop or FF sensor, but in my case, the crop camera did the better job.

 

[Marsu42]

So, I don't know which is better - crop or FF sensor, but in my case, the crop camera did the better job.

But, but, but it cannot be - ff is better, it has to be because it's more expensive this a is known truth :-> ...

... ok, jokes aside, you should do focus stacking in these situations - either via a tethered laptop or via Magic Lantern, this is exactly what it's made for. Closing the aperture too much kills the sharpness, and at the same time you don't get a nice/blurry background anymore.

 

[Loswr]

Though perhaps not strictly considered macro photography, I do a lot of photography of flowers. For many years I owned a crop camera (Original Rebel) and took many photos of flowers at distances of 2 to 3 feet on average. Since flowers aren't flat, having enough DOF to get a good percentage of the flower in focus is important - perhaps a DOF of an inch or so. This meant shooting at around f/11 with my Canon 100mm Macro (non-L) lens. Going to full frame and wanting to frame my photos the same, it becomes almost impossible to get the photo with a similar DOF. Again, this is trying to frame the photo the same - not crop - thus moving the camera closer to get the same shot and an adequate DOF. With the FF camera and the same lens, I now need to shoot at about f/20 to get the same DOF. Needless to say, if I need more than an inch of DOF, the lens apertures don't go high enough when using the FF camera. So, I don't know which is better - crop or FF sensor, but in my case, the crop camera did the better job.

What do you find almost impossible? Moving the full frame camera closer to the flower to match the framing? Stopping the lens on the full frame camera down to match the DoF? Raising the ISO on the full frame camera to compensate for the light lost by stopping down? The concept of equivalence means that after doing all of those things, you are getting the same picture in terms of framing, DoF, and noise. That's with sensors of the same generation, if you're comparing the image quality of a reasonably recent full frame camera to your old Digital Rebel, the IQ of the full frame will be significantly better.

The only time it's 'impossible' is if you're at such a narrow aperture on APS-C that stopping the lens down the extra 1.33-stops would exceed the minimum aperture of the lens (and in that case, as Marsu42 points out you're losing a lot of sharpness to diffraction and would be better off focus stacking with a static subject like a flower).

 

[Loswr]

But, but, but it cannot be - ff is better, it has to be because it's more expensive this a is known truth :-> ...

LOL.

I know you're joking, but in truth, in almost all situations from macro to wide angle to telephoto, a FF sensor will give you results that are either the same as or better than an APS-C sensor (the same when all factors are equalized to give the same picture, better if you don't need to match every aspect of the picture, and better if you need to use higher ISO settings…but worse if you need the full resolution of the smaller sensor for your required output). If smaller sensors were really better, then m4/3 would be better than APS-C, and the absolute best choice for everyone who shoots macro would be the Pentax Q with it's 5.6x crop factor.

Note that 'sensor' is an important point - when you compare cameras, other factors come into play - although not too important for macro, the better AF of the 7D vs. the 5DII is a notable example with which I have personal experience. System cost, as well as things like swivel screens, availability of Magic Lantern for particular bodies (trap focus would be enormously helpful for handheld shooting with the MP-E 65!), etc., are all factors to consider.

 

[Marsu42]

in almost all situations from macro to wide angle to telephoto, a FF sensor will give you results that are either the same as or better than an APS-C sensor

... It's good you're pointing out you're talking only about the sensor, not about camera bodies which might have features like a swivel screen, and not about other aspects like working distance.

So concentrating on the sensor, and assuming for the sake of argument that ff is "better" the question is: How noticeable is this difference, i.e. what export size, what audience, and is it worth the immense price difference for the camera and lenses? And until proven wrong I'd continue to insist that with macro photography, this difference rather small, if any.

But after going around in circles I admit at this point I'd really like to see some "same framing, same dof" examples of 20mp 6d vs 20mp 70d with 100L for different lens-object distances. I have my personal experience with butterflies and fireflies, but of course I cannot generalize that.

 

[Loswr]

So concentrating on the sensor, and assuming for the sake of argument that ff is "better" the question is: How noticeable is this difference, i.e. what export size, what audience, and is it worth the immense price difference for the camera and lenses? And until proven wrong I'd continue to insist that with macro photography, this difference rather small, if any.

Frankly, in many situations the differences are relatively minor (and as stated, for truly equivalent shots at relatively low ISO, the FF has no advantage at all - they are equivalent). What FF gives you is the ability to choose a thinner DoF if you want it, use a faster shutter speed if DoF isn't a limitation, have lower noise and greater post-processing flexibility, etc. The benefits of FF are most evident when pushing the envelope, so to speak.

Whether it's 'worth the immense price difference for the camera and lenses' is a decision everyone must make for themselves, based on need, want and/or budget. Is a Ferrari worth the immense price difference over the Subaru that I drive? Presumably yes, to the people driving them in stop-and-go traffic next to me on the highway commuting to and from work – but to me, no. Plus in certain, specific cases – such as driving on the highway when snow is falling at >2" per hour and the road crews can't keep up – I'd say my all-wheel drive Subaru is better than a Ferrari…at least, it was better than the Ferrari I saw spun off into the ditch on the side of the Mass Pike, that I drove past on my way home in a snowstorm a couple of weeks ago.

 

[mackguyver]

in almost all situations from macro to wide angle to telephoto, a FF sensor will give you results that are either the same as or better than an APS-C sensor

... It's good you're pointing out you're talking only about the sensor, not about camera bodies which might have features like a swivel screen, and not about other aspects like working distance.

Marsu, that is a good point - the swivel screen on my 60D rocked for macro and I miss it. I still think the FF ergonomic trade-offs are worth it for better IQ, but I spend more time on the ground than I did with my 60D. I often print at large sizes 20"x30" and up so the differences are noticeable, but for the majority of people that isn't a concern.

I will leave this post alone from now on, but in my opinion as someone who shots a lot of macro, all this DOF debate stuff is just a bunch of crap. Macro is hard, period, and a good macro lens and excellent technique are what matter most. The silliness I've seen in this thread won't make anyone a better macro photographer.

 

[Marsu42]

What FF gives you is the ability to choose a thinner DoF if you want it, use a faster shutter speed if DoF isn't a limitation, have lower noise and greater post-processing flexibility, etc. The benefits of FF are most evident when pushing the envelope, so to speak.

I know, that's why I put €1500 into a 6d though my 60d is still running fine. I was just surprised how little the (subjective) iq advantage is for macro and how much the loss of swivel screen & working distance hurts. The ff certainly gives you a different "look" for natural macro subjects, but that's more of a artistic advantage rather than something I could attribute to sharpness or noise.

The one thing I do continue to mention is the postprocessing flexibility you also mentioned, but if properly exposing & focus-stacking a mushroom I didn't find that to be really necessary. What I often really *would* need is simply more dr for highlights, but we talked about that and some fixes are available with bracketing or Magic Lantern dual_iso.

 

[BL]

I choose the M over FF most of the time for macro because of working distance.

 

[dtaylor]

I choose the M over FF most of the time for macro because of working distance.

Bingo. You can get the shot either way, but the smaller sensor will give you a little more room to work.

6 pages of people arguing tiny differences that make little or no difference in the real world or your final images. Sensors are so good now that there are only two categories where format seems to matter at all:

* Really low light stuff like astrophotography and astro-landscapes. FF tends to dominate here though you still see good work from APS-C.

* Wall sized landscape prints with incredible detail and zero noise/artifacts. You have to see these in a gallery to appreciate them, and they are all scanned and digitally processed LF film, or MF digital.

For everything else it matters little whether it's FF, APS-C, or 4/3. For some reason we love to pretend otherwise.

Looking over the best macros at a photo sharing site like Flickr, the key to top rated macro work is not format, but mastering focus stacking and lighting. Which camera do you choose? Whichever one appeals to your budget and desired features.

 

[eml58]

I was hesitant to make a comment here, but things seem to have calmed down a little.

I do a lot of Macro, albeit it's all Underwater Imaging, I have two set ups for Underwater.

1DMK IV in a Seacam Housing, I find the APS-H format just get's me closer and for my Macro Imaging works better than anything else I've tried (FF/APS-C), primarily it allows me to better utilise the 100f/2.8 Macro L IS.

For everything else I use the 5DMK III again in a Seacam Housing, FF seems to the wide angle Imaging better than the 1.3 Crop of the APS-H format.