Which is better, cropping a full-frame image or using a crop sensor?

I regularly do bird photography. With a 100-400 lens on my Canon 6D mII. And then cropping. Under certain lighting conditions, it gives a better result than using the crop factor on my 70D to zoom in. So it depends on your camera, your lens, the lighting conditions and the subject. Personally, I am very satisfied with this way of working, but it is not a black-and-white fact that one is always better than the other.

It depends on the subject. For bird photography where you are always short of reach, I prefer to use an APS-C (21MP). To photograph mushrooms or landscapes and portraits, I use a FF (24MP). If I were to use the FF for bird photography, I would throw away a lot of image information and have far fewer details left. The Nikon D850 would be a nice compromise because it is a high-density sensor camera with 46MP on FF. If you crop these images, you still retain (virtually) the same information as that of the APS-C with 24MP.

So it depends on the number of MP per surface area, or rather the photosite size, and whether you can photograph the subject filling the frame.

Donald Willemsen wrote on Tuesday 18 August 2020 at 11:23  | reply

I’ll stick with my crop cameras, otherwise I’d have to replace my EF-S lenses and I can’t afford that. If I still had to buy lenses now, I would of course buy lenses that can also be used on a Full-Frame.

I want to address the term crop (crop means cropping), because what do cropping and full image (full frame) actually mean. For that, we have to go back in time, to the time of film rolls. (they are still available, by the way). The term FF, or full image, comes from the fact that the 35mm negative was taken as the standard, and the sizes derived from that are smaller and are therefore called crop, depending on the crop factor compared to that 35mm film. But 35mm itself was once also a crop compared to the film formats commonly used at the time. Those included, with roll film: 6×4.5, 6×6, 6×7, 6×9 and 6×17, and with sheet film, all kinds of sizes including 4×5" inch. It also took some time before the professional photographer of the time dared to switch to 35mm film. So yes, what do you take as the standard?

I have a Canon 6D, 7D, 5DIII and a Sony A7RIII at my disposal, all with Canon L glass. Detail reproduction with the Sony after cropping is very nice, but actually you really have to be a pixel peeper to properly notice the differences. or view it at 400 percent in your editing program. Really focusing carefully and using a tripod gives much more quality result, than FF or crop... is my idea...

FujiFilm-X cameras are APS-C cameras. My previous Nikon D-7000 was also an APS-C camera. Yet I am much more satisfied with my FujiFilm-X camera, because the lenses are lighter and have smaller filter sizes. The lenses, all FujiFilm lenses, for those cameras are really designed and calculated for that APS-C system. There are some heavier and more expensive primes and they do not have the disadvantage of the consumer zooms, because they are much faster and therefore wonderful for close-up and portrait photography with beautiful (un)sharpness transitions.

4BYE wrote on Tuesday 18 August 2020 at 13:57  | reply

I've been using Sony for about a year now after having used Canon for 40 years (always an FF and APS-C body). After purchasing the A7 III, I wanted a second body as a backup. I spent a long time hesitating between the A6600 (the newest APS-C) and eventually took advantage of a great deal on the A7R III. With the 42MP, I can crop myself or use the 18MP crop mode beforehand. I have some difficulty with the very small Sony APS-C body and the fact that the viewfinder isn't in the middle and that it therefore lacks some buttons and functionality. Moreover, I can now work with practically two identical cameras. I can only endorse what I just read. The A7R III will indeed start to suffer from noise a little sooner, but with DxO PhotoLab I get very nice results anyway, even at higher ISO values. The Sony cameras are very good at that.

I assume that in my case, with the A7R III, cropping afterwards and using the 18MP crop mode give the same result?

And then the following: I also own an Olympus OM-D E-M 1 II with a 60mm macro and, since recently, a second-hand 300mm F4. In practice, the latter is a 600mm 4.0 that focuses sharply from as close as 1.4 meters. In good lighting conditions, a nice option for focus stacking and PreCapture. Options that aren't available on the Sony. I also suspect (I'm not technical enough) that those options are only possible because it is a Micro 4/3 system due to the smaller sensor and MP. For my other photography, I mainly use Sony FF. In my opinion, Sony has a better AF system for tracking and picking up action.

So my motto (I stole it from the man who pointed me to Olympus for macro) is "different tools for different jobs". After all, you always have to weigh up what ultimately gives the best result.

@lauran
because you can't always get close enough to your subject.

Nando, beautiful article.
Because I am mainly interested in nature photography and landscapes, I am rarely or rather never found in a studio or at a wedding or christening or sports event.
Walking and photographing in nature does, however, mean 'lugging equipment around'. That is why I chose micro 4/3. A huge saving in weight and size, not so much for the body but certainly as far as lenses are concerned … and … money. I chose Olympus without hesitation.
My latest acquisition, an E-M1X, has 21Mpixels on the crop 2 sensor. Olympus has come up with something for this camera to increase the photo resolution ‘without’ increasing the number of pixels on the sensor (I don't know whether several brands use this system?): namely, high-resolution shooting, so with a resolution higher than that of the sensor.
The camera takes a series of photos while the image sensor moves and combines these images into one single photo with a high resolution … without any loss of sharpness, on the contrary, with ‘increasing’ sharpness. Details that are normally not visible, even at high zoom ratios, are captured. My Olympus micro 4/3, crop 2, thus produces handheld photos of up to 50Mpixels (8200x6132) max ISO1600 and up to 80Mpixels (10400x7792) on a tripod, max ISO6400.
I have already tried out this technique, but have not yet needed it in nature.

What I'm missing is a clear answer, so at the same moment a photo with APS-C and full frame under the same lighting conditions and then assess the cropped photos, if necessary in the lab...and what is better then..that answer is what I'm missing

@ André
I obviously mean that a focal length of 300mm on crop 2 is equivalent to 600mm FF. In other words, much stronger telephoto performance for a cheaper price, smaller size and weight. So much better handling.

Paulussie wrote on Tuesday 18 August 2020 at 18:53  | reply

You’ve written such a clear piece, and there are still people who misunderstand it.....

I’ve had Nikon Dx cameras since 2007, the D80 first, 10 MP, later switched to the D7000, not for the pixels (it has 16 MP) but for the possibilities, and for the past year and a half the D500, again for the possibilities, mainly the viewfinder.
This one has 20 MP. So I also have a lot of specific Dx glass, especially wide-angle, and for Dx that ranges from 10 to 24 mm, so on FF 15-36. It can be even better, because Sigma has the 8-16, which is 12-24.
So the wide-angle argument isn’t entirely valid.
At the telephoto end, however, Dx has a big advantage with the one-and-a-half-times magnification. I don’t have bags of money lying around somewhere, so I’m very happy that a telephoto lens brings so much less into the frame. And my macro. 105 becomes 160, and then 1:1, wonderful, and my Sigma 150-600, which gets a range of 225-900.....try getting that with FF.
But for portraits I can imagine having an FF, with the 24-70 or the 80-200.

You write that the new full-frame cameras have 45 to 50 million pixels on the sensor. This is not correct. A photograph consists of pixels. The sensor has receivers on it.

@ Robert Lerou
Technically speaking, they are indeed 2 different hardware data points. The sensor receives, the image projects (and when you print, they are in turn dots).
But even 'all' camera manufacturers (at least the ones I know) use the term pixel for the sensor. So let's just stick to pixels, including for the sensor.

@ Jacques Klarenbeek.
You state unequivocally: “Of course you have an advantage with a Full Frame camera.” Well … for me that would mean a huge ‘disadvantage’.
First, a few facts that a priori have nothing to do with this article by Nando but are more than worth mentioning.
Know that I am a lover of nature, landscapes and macro.
1. Weight and size. As a 67-year-old with some physical limitations, a reduction in size but mainly in weight means a huge advantage: less pain, walking farther.
Moreover, everything becomes bigger and heavier, just to name one: tripod (to guarantee the same stability). A tripod that you will need much sooner, so indispensable to take along.
2. Budget. The price difference is not always in the body (one of my micro 4/3 bodies also costs €3000) but in the much higher cost of FF lenses when you want to achieve the same low F value. And it doesn’t stop there: for example, much larger and more expensive filters.
Now the actual question: “What is better, cropping a full-frame image, or using a crop sensor?”
I use micro 4/3 and will make the comparison with that. (I am not taking actual size and working size into account.)
FF sensor size: 864mm²
Micro 4/3 size: 225mm²
Ratio: 864/225 = 3.84
Let us assume a sensor that can generate 24 megapixels. Obviously, with a FF you can go to more pixels when you put the necessary EUR next to it.
To crop the FF to the same size as micro 4/3, you therefore retain 24/3.84 = 6.25 megapixels, while the micro 4/3 has 24 megapixels. What a difference. So cropping with a FF: negative result.
Yes, but I can already hear many saying: NOISE.
Well, over the past 5 years I have not taken 10 photos with an ISO higher than 6400 as part of my hobby. I always photograph in RAW, in JEPG the following story may be somewhat different.
(Chromatic) color noise (caused by temperature and length of exposure) is distracting but, up to ISO6400, not noticeably present even in the darkest parts of the photo and can easily be removed with good editing programs (which you can then still apply locally), and … with minimal loss of sharpness.
Monochrome or luminance noise can also be easily removed. And I don’t always find that distracting. Sometimes I don’t remove it or only reduce it minimally.
My conclusion: noise, no longer a problem with a 4/3.
I also photograph close-up and macro 1/1 and higher (2/1, …). What an advantage with a 4/3! I can stay much farther away from my subjects and still get them just as large in my photo as with an FF.
General conclusion (for my applications): “Of course you have an advantage with a crop camera.”

That is indeed the dilemma I am struggling with.
I like photographing in nature (wildlife) at the edges of the day and preferably in the forest: Always too few mm's and too little light. With my Sigma 150-600S at F6.5, therefore often a lot of noise and motion-blurred photos on my 7D mkII. So I am now considering a (second-hand) 5D mkIV.

Hello Nando,

I will soon be the proud owner of an EOS R6, that is, if it gets delivered.
This body has 'only' 20.1 MP, which is exceptionally low, but the pixel size is 6.56µm.
It is not only the max resolution that matters, but also the pixel size. Is this correct?

Guido

My take is:
With a comparable number of MP and the same generation of sensors, a FullFrame sensor has the advantage when you can get the subject fully in the frame. Your image will then have a higher dynamic range due to the larger photosites (pixels) and therefore capture more information (less noise). As soon as your subject covers less than 2/3 of your image, the APS-C will have the advantage because more details are retained. If you often have to crop with an APS-C, then don't switch to an FF either (the exception is a high pixel density FF such as the D850, but that is not comparable either.