I get asked this question a lot; so often that I’m going to write a general response. This doesn’t replace the personalized advice that I have given and will continue to give, but it will add to it.
For whom is this article intended? I’m thinking of someone who already owns an interchangeable lens full frame (FF, or 24x36mm), and has at least several years’ experience in using that gear. If all your previous photographic experience is with your cellphone, this piece isn’t for you, and a full frame digital camera will probably be a better fit for you than a medium format camera.
What’s a medium format digital camera? The term “medium format” comes from the film era, and traditionally referred to formats larger than miniature format (24x36mm, 24x32mm or 24x18mm negatives or transparencies on 35mm film stock) and smaller than images on 4×5 inch sheet film. Today, when referring to digital cameras, it almost always means any format with sensor image dimensions of greater the 24x36mm. Medium format cameras are thin on the ground when compared to FF ones, and almost all of the medium format digital cameras currently being manufactured use 33x44mm sensors made by Sony. Pentax still makes a single lens reflex camera that uses a 33x44mm sensor, but their product line has been stagnant for years, and I don’t expect further MF DSLR developments from them. As far as I know, there are no fixed lens 33x44mm sensor cameras being made, and no other MF DSLRs. Thus, the main choices for a newly manufactured MF camera boil down to either the Hasselblad (X series) or Fujifilm (GFX) mirrorless interchangeable lens cameras (MILCs).
What do you get when you lay down a FF camera and pick up a medium format one? I will generalize, ignoring some cases:
Greater resolution. You can buy 50 MP GFX and X1D cameras, but you’ll be missing out on some of the greatest benefits from the format if you’re already using a 40-60 MP full frame camera. The 100 MP resolution of the GFX 100x and X2D cameras can not only allow more detail but serves to mitigate aliasing. Cameras with greater resolution can allow more cropping for the same print size than cameras of lower resolution, but my position on cropping has always been: if you often crop your images in both directions, you are either using the wrong equipment for the subject, or you’re not planning the shoot as well as you should.
Dynamic Range. Current CMOS sensor technology provides effective full well capacities of about 3000 electrons per square micrometer. If you use FF equivalent focal lengths and f-stops with your MF camera, and can double the time your shutter stays open, you will have a signal to noise ratio (SNR) in same size prints that’s about half a stop better than you’ll get with a full frame camera. If you are limited to the same shutter speed, you’ll see about the same SNR.
Better lens performance at equivalent apertures. This is by no means guaranteed, but all else equal, it’s easier to design and manufacture slower lenses than fast ones, so there is likely to be less vignetting and higher resolution off-axis on the MF lenses.
4:3 aspect ratio. Whether this is a plus or a minus depends on your esthetic choices. I like 4:3, 4:5, and 1:1 aspect ratios, so a 4:3 aspect ratio lets me use more of the capture than the 3:2 aspect ratio of a FF camera.
Leaf shutter. The Hasselblad XCD lenses all have leaf shutters, with can have advantages when using strobe lighting, but can also suffer from strange bokeh at high shutter speeds.
What do you lose?
Lens selection. If you’re using a mirrorless camera like the Hasselblad X series, the 907X, or the GFX cameras, you can use many third-party medium format lenses, and even quite a few lenses made for FF cameras. With the Hasselblads, you’ll be stuck with the very slow scanning electronic shutter, but with the GFX cameras you can use the EFCS or fully mechanical focal plane shutter. But you won’t be able to use lenses made for mirrorless FF cameras, and you will usually loose autofocus entirely or suffer with decreased AF performance. With a camera like the Sony alpha 1/7/9 series or the Nikon Z-mount cameras, there are many more lenses you can use.
Autofocus performance. Modern stacked-sensor FF cameras are miles ahead of medium format ones when it comes to properly focusing dynamic subjects like birds and sports. They’re also better for active children.
Frame rate. Some modern medium format cameras are capable of frame rates that full frame cameras would have been proud to be able to do a few years ago, but stacked sensors in full frame cameras have raised the bar so high that MF cameras can’t get there. There are currently no consumer stacked-sensor medium format cameras.
Lack of a mechanical focal plane shutter. The Hasselblad X-series cameras have no focal plane shutter, which means that you are likely to get rolling shutter effects when adapting lenses with no leaf shutters to the camera.
Weight, size, cost. Usually, but not always, medium format cameras will be heavier, larger, and more expensive than comparable full frame cameras.
Where do the medium format advantages become significant?
The most important place is when making large prints. You’re not going to see much difference between, say, a GFX 100S II capture and one from a Nikon Z8 displayed full format on a 4K monitor or even in a 16×20 inkjet print. But in a 30×40 inch print, with the right subject and good technique, you’ll see a difference. For most web usage, equivalent images from the two systems will appear virtually identical. There is a future-proofing argument to be made here; you may not make large prints now, but you may want to do that someday. You may not have a 16K monitor now, but you may get one someday.
For a great many people, the full frame camera is the way to go. You’ll save some money, get a much larger lens selection, enjoy snappy response and responsive autofocus. But for those who want the ultimate image quality, print large, have deep pockets, and can live with medium format limitations, they can be great cameras.
Dear Jim,
a well reflected and founded argumentation.
I for myself see 2 other points to add:
– flexibility for cropping, maintaining the described advantages
– specialising in different applications:
-“static objects”: for architecture, landscape or even some streetscapes I prefer the super- solution and “clear and lucid” MF-raws without any moiree and aliasing at 102 mp
-“moving photographer and targets”: if I travel etc. or am targeting people or something moving, I use a FF cam, because of its smaller size etc.
(i bought most items second hand, the only way I can afford this dual strategy;-)
best, Tom
You skipped over the Phase One offerings which still include an SLR style body and up to 150MP resolution with a full size 645 sensor. Leaf shutter lenses also allow high shutter speed flash synch. The price does limit its reach though.
If you’re considering a P1 IQ4 150, you’re probably knowledgeable enough that you don’t need an article like this one.
I would argue that you lose a decent amount of the resolution advantage on Mini-MF (GFX and X series) cameras due to the slow aperture of most of the lenses. In FF f/2.8 zooms and f/1.4 primes are standard where as most Mini-MF standard lenses start at f/3.2 or 4 with telephotos lenses starting at f/4 or f/5.6. If you look at lens simulations from patents available here, allot of those don’t perform well wide open an actually benefit from stopping down. This puts you at f/5 or 5.6. At that point you’re heavily diffraction limited on the 3.76um pixels and this just gets worse with the next generation of sensors at 3um.
The lens simulations can be found here: https://www.zhihu.com/people/xgordon
Also you generally have worse low light performance as the larger sensor size doesn’t make up for smaller aperture lens.
On axis, at optimal apertures, I have not found a GF lens that can’t lay down detail (in many cases, a lot more detail) than the 101 MP sensor can properly resolve. The lenses are far from what’s restricting MF resolution.
At 550nm, the first null in the airy disk of a f/4 and f/5.6 lens are 5.4/7.55um. So you’re already suffering pretty badly from diffraction as your pixels are 3.76um, this is only going to get worse with 3um pixels.
First off, you shouldn’t be looking at the first null, but at 70% encircled energy radius. Second, what’s more important in my thinking is the spatial frequency at MTF10 for the lens. That’s more important for aliasing.
I feel that the first null (~84%) is pretty decent approximation. Even if we use 70% encircled energy, you’re still heavily diffraction limited at f4/5.6.
If you’re diffraction limited and your spot sizes are on the order of ~6um, your spatial frequency for MTF10 is not going to be as high either. Aliasing doesn’t really bother me and likely allot of other folks, as aliasing on non-repetitive patterns isn’t too apparent. Either way there’s still tons of actual information to extract there.
Finally as much as I dislike this, ML based demoiascing is already used on iPhones for increased resolution and reduced aliasing, and it’s only a matter of time before that comes to lightroom and similar raw processors.
I use the FF Canon EF 35mm F2.0 with little issues on my GFX100S. Good AF for street photography. The tiniest hint of vignetting. Here is the full jpeg file. No Crop. Massive Rolling Shutter effect here … which I like! https://images12.fotki.net/v1681/filejDUQ/a/4/43793/4909192/05221920.jpg/+/0522%201920.jpg
I am sure MF can show me more detail than my Nikon Z.
Still as you say the difference is seen in prints larger than 20inch wide.
Nikon and others has a pixelshift mode that can be used on static objects in static light conditions.
In that case it can resolve far more detail and accurate color with some of the new lenses and even old ones.
This mode can be used for reproductions for instance and even architecture in some cases.
I make a lot of panorama’s ; Also a way to increase the amount pixels. These methods can even be combined in some cases.
Then a FF-camera is faster – resulting in very fast focus-shift photography of about 8 frames/sec to get more DOF.
All in all – the group of people that really benifit from MF is getting smaller.
Thank you for this terrific summary. The only item that could be worth reconsidering – but possibly only in terms of one medium format camera – regards autofocus performance. The Fuji GFX 100S II, which I’ve now been shooting with since its release in June, offers remarkable autofocus performance, given its subject detection capabilities. I’ve shot fast flying and erratically moving birds and wildlife against complex backgrounds with this camera to great success. The autofocus performance ranges from very good to jaw dropping amazing when coupled with the subject detection options. The GFX 100S II may not yet match smaller FF autofocus capabilities, but it’s certainly not miles behind. And as I’ve better understood its strengths and limitations, my sharp capture rate just keeps going up. The GFX 100S II indicates that the gap between autofocus capabilities of FF and medium format more generally will quickly close in the near future.
I moved to 100 megapixel GFX from 36 megapixel FF. A big leap on paper. In practice, I find that even at 40″ print sizes, the best prints from the small camera can mostly equal the GFX camera. Differences start showing up consistently at bigger sizes.
I find that with the GFX camera it’s much EASIER to get that great 40″ print.
Also, every GFX lens is excellent. Only some of my FF lenses were.
I should mention that for the work I do, diffraction is typically working as an equalizer. I usually need to use f16 or f11 for depth of field. Also I have no experience with the best current FF mirrorless systems.