There is a recurring theme in many Internet fora that there is a “look” to medium format (MF) images apart from their generally higher acutance and detail, even when shot with lenses and settings that are equivalent to their full-frame (FF) counterparts. The claim is that the look is so strong that it survives downsampling to web resolution.
I am not a believer. I think that the MF look derives from a combination of generally better lenses and generally better photographers. If you compare the images posted on the Facebook GFX group page with those of, say, a Sony a7x one, the images are unquestionably of higher quality. But I don’t think that’s because the GFX cameras imbue their users with super-photographer powers; it’s because most of those folks were pretty darned good before they ever picked up a Fuji MF camera.
But I’m an experimentalist and don’t like to have to trust my gut, so I decided to do some testing to see what varying the format, and prety much only that, would do. I started with a Fuji GFX 50S, which has a 33×44 mm sensor. I wanted to compare it with a camera that had a sensor with the same area as a FF camera – 864 square millimeters – but had a sensor with an aspect ratio the same as the GFX’s 4:3, making the sensor size 25.46 by 33.94 millimeters. It would be nice if that camera took the same lenses as the GFX 50S so that I could easily take images with both cameras without changing the camera position.
But where to find such an instrument?
Fortunately, I figured out how to make one. I call it the GFX 30S. You start with a GFX 50S and create a Lightroom preset for a centered crop to 4800×6400 pixels. Presto!
I put the 32-64/4 zoom on the GFX (both of them!) and did a trial run. As is often the case, there was an oopsie. The markings on the focal length ring of the zoom are far enough off that the field of view of the GFX 50S and the GFX 30 S was different even when I dialed in equivalent focal lengths. I tried to fix that by bracketing the focal lengths around the correct indicated value. It turns out that you need to match focal lengths quite accurately in order to make the comparisons look alike, and I never managed to gets sets of images that matched well enough to prove the point.
Another problem was setting equivalent f-stops. The GFX 30 S needs an f-stop that is somewhat over two-thirds of a stop wider than the GFX 50S, but well short of a full stop wider. Getting that difference set accurately proved to be as difficult as setting the focal length accurately.
As if that wasn’t bad enough, focusing turned out to be an issue. I initially told the camera to autofocus on Chauncey’s (that’s the name of the bronze bunny) nose. The focus from image to image turned out to be soo far off that it affected the far-OOF bokeh. I tossed all those shots and fell back to manual focusing. It’s not that the AF in the GFX is inaccurate, exactely, it’s that the AF area can’t be set small enough for this subject.
So, ultimately, I wasted most of a day and never did get a set of images that made the comparison I was trying to make. For what it’s worth, here’s one set of images with a focal length of 64 mm for the GFX 50S and 49 mm for the GFX 30S. It won’t take too much in the way of close inspection to see the differences created by lack of equivalency in focal length and aperture.
If getting equivalency right in demonstration shots like this is so darned difficult, it adds to my suspicion of sets of images taken with different cameras and different lenses from slightly different positions that purport to demonstrate the existence of the MF look’s insensitivity to downsampling.
This whole exercise hasn’t been a complete waste of time for me; I now have a much deeper appreciation of the level of matching of aperture and focus location that’s needed for these kinds of tests. As to focal length, I guess I had an intellectual grasp of the need to match it accurately, I didn’t understand that very small changes in focal length would make such a difference in the resulting match.
One thing I’ve noticed when comparing APS-C+85mm to FF+135mm is that the longer focal length on the larger format has more breathing at the same focus distance, both being unit focusing primes (though maybe exit pupil location matters). So while 85*1.6=136, extremely close to my 135mm lens, the end result has a significantly wider field of view.
Good point. There may be some distance where the FL markings on the 32-64 are more accurate.
Speaking of a “look”, I have a story.
Guy came to a Leica forum. Posted a bunch of shots. Everyone commented about the recognizable look of Leica lenses, “Mandler” glow, they instantly recognized the “look”. Guy revealed shots were taken with a Canon 10D and a 18-55mm kit lens.
Dpreview MF forum is the new Leica forum.
Erik Kaffehr says
I fail to see the failure. A very good demo. Variance in lens distortion combined with software correction may also play a role.
I downloaded your first two images and input as layers in photoshop. I also aligned those layers, which would eliminate most of the difference in lens distortion, I would guess.
Those image look pretty similar to me…
Jack Hogan says
GFX-30S? Love it!
Maybe your endeavour would have been easier with a GFX-25S? 😉
Tom Pietryka says
I do have to wonder if simply cropping a MF image is the best test of this – it eliminates variables like the different image processing engines or any sensor differences besides size/resolution. I would probably have compared the best of full frame, something like the Z7 with an Otus.
Nigel Danson recently did a comparison of the Fuji XT3, Nikon Z7, and GFX 50R on prints, and he concluded that the main difference was the lenses, with the GFX lenses being superior to the X-mount and F-mount lenses he was using, though he did note that his Z-mount 24-70 was super sharp, on par with the GFX.
I think that the best full-frame cameras today probably perform on par with the Fuji MF cameras, though I wonder if the Leica and Hasselblad do any better. The “medium format” look was probably more true in past years before FF caught up, but mainly I think it’s an idea carried over from the film days, when there was (and is) undoubtedly a major difference between 35mm film and 120 film.
And that was my intent: to see what changing the format, and only the format, did. Unfortunately, I couldn’t control the variables accurately enough.
Tom Pietryka says
I do think that your images are enough to conclude, however, that the size of the sensor alone does not result in a big enough difference to be called a different “look”. It seems to me the only inherent differences, assuming lenses and sensors that perform the same, are the differences of having different focal lengths for the same field of view – shallower depth of field and less distortion. Certainly MFT has a different look because the short focal lengths result in very little bokeh, but when comparing FF to MF or APS, the difference is more subtle.
I would have to agree with your initial theory that the main reason for any “medium format look” is generally better lenses, but lenses like the Sony G Master series and Nikon S-line are closing that gap (if they haven’t already).
Jack Hogan says
“…the main reason for any “medium format look” is generally better lenses…”
Right. Plus folks tend to evaluate lens performance in lp/mm. Even if both lenses had the same performance in lp/mm as setup, MF would typically ‘look’ sharper because it typically has more mm and more pixels. Same with ‘tones’. Hence the ‘more’ look.
Herb Cunningham says
How would Micro 4/3 compare in such a situation?
The difficulties of achieving equivalent conditions would be increased, since I’d have to change lenses to get the FL’s equivalent. There would also be fewer pixels on the GFX 7S, and that might affect the downsized resolution.
I enjoyed reading this post and the comments. I would agree with your conclusion that there is little to no discernable difference between GFX50s and GFX30s images. Simply using a smaller / larger sensor area does not define that mythical “MF look.” However, as you’ve already said, eliminating all other variables other than sensor size is an impractical endeavor. 🙂
I would go further and say that such an endeavor is a bit like trying to define an elephant by its one, most obvious feature, its trunk. Obviously an elephant is more than a trunk. Just as Fuji MF is more than a “larger sensor.” It’s the combination of all variables that add up to the special look that entices people to empty their wallets at the GFX booth.
I tend to feel that the quest for “equivalence” is not only difficult, but also irrelevant. The variables in question when discussing equivalence are generally sensor area, aspect ratio, dynamic range, resolution, native lens quality, focal lengths, apertures, and ISO noise performance. Even when you “equalize” as many of these variables as possible, you still have others like operational ergonomics, color rendition, size/weight, price, brand loyalty/customer serice, system accessories, and on and on. Even further, the GFX being a mirrorless system, allows for a virtually unlimited combination of vintage adapted lenses combined with the larger sensor and all the other variables that come along with it.
The enticing, indefinable MF look is the unique combination of many variables that simply don’t exist elsewhere. Is that something the marketing agents can use to induce money hemorrhage in all customer bases? Unlikely. For now, they are limited to unsuspecting neophytes and indefatigably discerning amateurs/professionals constantly searching for unique tools. 🙂
Oskar Ojala says
An interesting comparison and the difficulty of comparing is useful (and expected) in itself. When encountering something about the “MF look” on the Internet, it’s unclear exactly what is meant. I would think it primarily means the DOF and focus behaviour, since sharpness and tonality tends to be high with modern digital and one needs a relatively big reproduction to demonstrate a meaningful difference between MF and high quality 35mm.
That said, how to compare DOF and how the focus changes across the image? Sensors will be different, as will be lenses, making it questionable that a really objective comparison can be achieved. In the past, MF enjoyed a shallow DOF effect, but the much improved fast lenses for 35mm as well as digital MF being smaller than analog crucially narrows this gap.
Thus, I’m not convinced that there’s any other “MF look” nowadays than simply higher resolution, but that doesn’t show up in small reproductions.
If you want to see an extreme example of the MF look (for me), check out some 6×7 MF or 4×5 LF shots and their DOF. I’ve seen some incredible group photos taken with the Pentax 67 and 4×5 cameras, where the group of people are separated from the background with bokeh, even when it’s shot from a distance. With 35mm I’ve noticed that I have to use my Canon 85/1.2 to even get close to the feel of my Hasselblad (49mm sensor) when it comes to DOF. The MF look is very real.
I don’t think anybody is saying that you don’t get less DOF at the same stop with large format. I used an 8×10 for years, and I sure know that. So do the folks who were doing portraits with the Polaroid 20×24 camera. But at equivalent stops, defocus blur is the same in all formats.
1. Does the focal length not impact the image? There us much talk of lens compression. It should be more pronounced in close ups with such small differences in sensor size.
2. Does it mean that it’s only the distance to subject that plays a role in the “compression of image”?
It impacts the field of view and the depth of field. It does not impact the perspective.
Not sure quite what you mean by compression of image. Can you define it mathematically? I can tell you that images with the same field of view and the same subject distance and equivalent f-stops will have the same perspective, and the same DOF.
Erik Kaffehr says
If you use a longer lens you need to move back to cover the same subject. So, if you shoot a half length portrait with say a 100 mm lens at 3 m, you would need to move back to 6 m with 200 mm lens to get the same composition. So that gives you a different perspective.
Now, figure that you shoot the 100 mm lens on 24×36 and the 200 mm lens on 6×7, which about twice the width of the film. In that case you would be able to shoot from 3 m and have essentially the same composition as with 100 mm and everything related to perspective would be the same.
This video explains it pretty well: https://youtu.be/_TTXY1Se0eg
So the essence is:
A longer lens allows to shoot at a longer distance using the same film or sensor size.
Depth of field is dependent on the physical size of the aperture. So if you shoot at say f/2 on the 100 mm lens, it would have an physical aperture size of 50 mm, the 200 mm lens shot at f/4 would also have a physical aperture of 50 mm. So, if the camera would not be used depth of field would be the same.