amfoto1 Loc: San Jose, Calif. USA

Today's "crop sensor" cameras are darned good and capable...

In fact, I'd wager that a lot of people who feel the need to "upgrade" to full frame actually get little or no benefit from the larger format.

Full frame AND APS-C format (like your 80D) each have advantages... and disadvantages.

Generally speaking, compared to the smaller format a full frame camera will have a "less crowded" sensor with larger pixel sites, which in turn allows for higher ISOs to be used before digital noise is a problem. The reason for this is that due to the less crowded sensor there is less "cross talk" between adjacent pixels, as well as less heat gain. Both those lead to noise in images.

Just for example, a 20MP, APS-C Canon 7D Mark II and a 50MP, full frame Canon 5DS camera have almost identical "pixel pitch"... nearly the same size and density of pixels on their respective sensors. Your 24MP APS-C 80D has a slightly more crowded, sensor. The new 32.5MP APS-C 90D has a significantly more crowded sensor! (If that sensor were scaled up to full frame with the same pixel size and density, it would be about 83MP!) A 30MP full frame 5D Mark IV or a 26MP full frame 6D Mark II have substantially lower density than 7DII or 80D.... and a whole lot lower density than 90D!

Interestingly, a 7D Mark II and your 80D each have a native ISO range from 100 to 16000. (This is the non-expanded range... I avoid the expanded ISOs because they simply get too noisy, but have used my 7DIIs at their 16000 setting with reasonable success.) The full 5DS-series have a native range of 100 to 6400! But the full frame 5DIV has a range of 100 to 32000 and the full frame 6DII has a range of 100 to 40000.... one stop or more higher than either of our APS-C cameras.

All these ISO ranges are MUCH higher than was possible with cameras in the past. The 6MP, APS-C Canon 10D I bought in 2004 I'd use no higher than ISO 1600. The same with the 8MP, Canon 30D that replaced them. With my 15MP Canon 50D I'd use as high as ISO 3200 at times, but never higher than that. The pair of original 7D that replaced those, I'd push to 6400 at times. And the 7DII I use now can equal the quality of those images at 12800 or even 16000. It's still brand new and we'll have to wait for more thorough reviews, as well as any firmware updates and software improvements that effect high ISO performance, but the 90D appears to have high ISO noise pretty similar to your three year older 80D... in spite of the fact that the 90D has a 35% boost in resolution (32.5MP vs 24MP).

Another example, years ago I added a 21MP Canon 5D Mark II to my kit, to some extent for it's high ISO abilities. I was able to use it up to 12800, for my purposes. That was one to two stops higher than I would use with the APS-C cameras that served for most of my work. I continued to use the 21MP full frame 5DII until I got my 20MP APS-C 7DIIs. Those are equal to or better than that older full frame camera. So some day I'll need to upgrade it, though I really don't have a lot of need for any higher ISO (so far).

So, while full frame can still have some high ISO advantages... Both APS-C and full frame have improved and advanced with each successive generation of sensors and processors. Image editing software has some role in this, too, as more and better noise reduction has become available. The difference in ISO performance is still about a stop or a little more, all else being equal. But both are capable at such high ISO now that I can't help but wonder how high ISO people really need!

The next difference between the formats has to do with depth of field (DoF). A full frame camera can potentially render both shallower and deeper DoF. Let me explain a little. It isn't actually the difference in size of the sensor alone that makes for this difference. DoF only changes due to three things: distance, lens aperture, and lens focal length. However, if you photograph a subject and want to frame it the same way, with full frame you will either need to get closer or use a longer focal length lens... either of which will give the effect of shallower depth of field at a particular lens aperture. Because of this full frame has the potential for about one stops worth of stronger background blur effect, compared to APS-C.

At the other extreme it's similar. Again, it's indirect factors that allow smaller lens apertures to be used on full frame. Diffraction is an optical effect that reduces image quality when using small lens apertures. A full frame camera can be used about one stop smaller lens aperture than APS-C, before diffraction becomes an issue. The reason for this is magnification. When you make a print of any given size, you need to magnify the original more with an APS-C camera, than you do with full frame. For example to make an 8x12" print with a full frame image calls for approx. 8X magnification, while to make the same size print from and APS-C image will mean approx. 13X magnification (both assuming the image isn't cropped). The higher magnification of the APS-C image will make any loss of IQ to diffraction.

For example, with my 20MP APS-C Canon 7DII cameras I know there's a "diffraction limited aperture" of f/7.1. In comparison, the DLA of my 21MP full frame Canon 5DII is approx. f/10. That's about one stop smaller aperture, before diffraction begins to occur with the full frame camera (also assuming an 8x12" print viewed from "normal" distance). These don't mean I can't use smaller apertures.... it's just the aperture at which diffraction begins to occur and it's very little at first, increases as smaller and smaller apertures are used. I'll shoot with my 7DII at f/8 and f/11 without much concern... maybe f/16 at the very smallest. In contrast, I'll use f/11 and f/16 with the 5DII, and maybe even f/22.

So, it can be argued that full frame has a "wider usable aperture range"... stronger effects with large apertures, better image quality at smaller apertures, although in neither case is it directly because of the difference in sensor size.

Someone who is planning to do a really large print, who is going to be magnifying their image a lot, will want the larger sensor format. But with the capabilities of modern APS-C cameras, up to 13x19" and maybe even 16x24" there won't be a whole lot of difference to be seen from normal viewing distances. Note that magnification also can be a factor when it comes to the appearance of noise in an image.

Disadvantages of full frame cameras include a more limited selection of lenses.... they basically require full frame capable lenses, while an APS-C camera can use both crop-only lenses and full frame capable lenses equally well. And full frame capable lenses tend to be bigger, heavier and more expensive. (They are separate subjects, but very high resolution cameras in either format are also more "demanding" to work with. They will show any lens flaws more obviously, so require better corrected, higher resolution, premium quality lenses. Very high resolution cameras in both formats also are more susceptible to camera shake blur problems, calling for more careful technique, using higher ISO to allow for faster shutter speeds and employing image stabilization whenever possible.)

Basic rules of thumb should be that folks who use telephotos a lot will usually do better to use APS-C cameras... while photographers who use wide angles more frequently may find full frame beneficial. Folks shooting sports, wildlife and some other action subjects may benefit from faster shutter continuous shooting rates, faster flash sync speeds that may be possible with the crop camera. People putting cameras on tripods and taking scenic shots, portraits or macros may find full frame fit their needs better.

I do a lot of sports photography (and some wildlife) using telephotos. I'd much rather hand hold my sub-3 lb., $1300 300mm f/4 lens on an APS-C camera, than haul around an 8 lb., $9000 500mm f/4.... and a tripod to sit it upon... that's necessary to "have the same reach" with a full frame camera!

OTOH, when I'm shooting a landscape with with my 20mm that lens can only show it's full capabilities on a full frame camera (another reason I have both formats in my kit).

The DSLRs themselves in both formats are almost identical in size and weight. The lenses they each call for are vastly different.

I would argue that today's APS-C cameras are more than good enough for most peoples' uses. There are very likely a lot of people who have spent extra $ for full frame and appropriate lenses... who haul around a bigger and heavier kit of gear... who actually get little to no benefit from it. They don't print large enough to really see any difference. When is the last time you made a print bigger than 13x19"?

I suspect part of the reason people think they need a larger format camera is the way they handle their images after they take them. They take them home and view them on their computer monitor. And, they often do so "at 100%". With a 24MP camera like your 80D, on most computer monitors 100% is like making a 60" x 40" print, then viewing it from only 18 or 20" away! Even if you do plan to make a five foot by three and a half foot print.... you would need to step back several feet away to actually view it!

They're evaluating and judging their images at far higher magnification than necessary... far larger than anyone else will ever see them! By the time the images are resized for printing at more "normal" print sizes... or reduce resolution and size even farther for online display and sharing.... chances are a lot of that "full frame goodness" they briefly saw on their monitor will disappear. When it comes to evaluating images on your computer monitor for sharpness, noise, focus accuracy, etc. a magnification of 33% will render a much more realistic view. It's fine to use high magnifications like 100%, 200% or even higher for retouching and to check for artifacts so as to not over-sharpen images, and perhaps some other careful post-processing work.... But makes no sense for overall image judgments.

Think long and hard about it... before "going full frame". It just isn't necessary or beneficial for most people. The quality today's crop cameras are capable of are more than enough! In fact, they might be better served buying better lenses for use on their APS-C camera, rather than going to full frame and having a more limited selection.

Heck, why stop with full frame? If you're actually going to need the capabilities of a larger sensor, maybe that won't be enough and you should be looking at medium format cameras, which in recent years have come down in price considerably at the same time they've seen improvements in autofocus systems, frame rates and other ways. At the other extreme, if you're traveling and need to lighten your load a lot, you might want to consider formats smaller than APS-C, such as Micro 4/3 or even 1" (aka, "CX"... however i don't think anyone is making interchangeable lens cameras using that format now, since Nikon dropped their mirrorless line that used it several years ago).

PHRubin Loc: Nashville TN USA

I don't understand!

I only have APS-C or smaller sensor cameras. I really don't understand how a 24MP full frame is better than my 80D for landscapes. Yes, your 20mm lens is wider on a FF, but my 11-20 can give me the same AOV and you can't use it at the lower zoom levels without vignetting. To me, the significant difference is noise levels which is not a concern in bright daylight. Another difference is DOF which for a crop sensor for the same AOV, a smaller focal length is required giving greater DOF. So am I mistaken? Other than noise, all else being equal including MP count but not lens used, isn't the crop sensor just as good or better for landscapes?

Bill P

PH,

You are missing the point here. A FF camera makes the owner think a certain part of his anatomy larger, just like big SUV's and pickups do.

PHRubin Loc: Nashville TN USA

But that won't show in the photo

CHG_CANON Loc: the Windy City

There is nothing deep down inside us that can't be fixed by a larger sensor.

kbk

There is a good you tube video on this subject comparing full frame vs crop cameras. Remember the math;
50mm lens on FF ÷1.6= 30mm on CF Camera gives equivalent focal length views

FF camera aperature = aperature ÷ 1.6 in a CF camera will give equivalent bokah or focal depth,
But if you change the aperature in the CF camera, to get the same exposure, you will have to change iso or shutter speed.
The video also goes into the math about equivalent iso settings between CF and FF.
The video shows how with both cameras you can obtain equivalent pictures and therefore you do not need a FF camera. The problem is that manufacturers do not make equivalent lenses for CF cameras. For example you can buy a 50mm lens for FF but not a 31.25mm lens for CF camera, you can get a 30mm lens which is close enough or use a zoom lens which can get you close to 31.25mm...

Bill P

I certainly hope.

SuperflyTNT Loc: Manassas VA

Probably not without a macro lens. 😜🤪

DaveyDitzer Loc: Western PA

amfoto1,
Thank you for the time you put into your response. I appreciate it.