Some people shoot full frame lenses on crop sensor cameras. More people should shoot medium format lenses on full frame cameras.
If you are like me, you have held on to some of your film photography gear. Though I have been working through selling/giving away most of it, I intend to keep at least two 35mm cameras (my Nikon FA that I fell in love with after reviewing it and my Nikon F2 that I trust will still be working for decades to come), one medium format camera (my trusty Mamiya 645 Pro-TL), and one large format camera (Intrepid 4x5 Black Edition). Otherwise, I intend to stick with and expand my digital lineup. For a while, I thought for sure that when the day comes that my Mamiya 645 stops working and is beyond a simple and expensive repair, I will pick up a medium format digital camera – likely a camera from the Fujifilm GFX lineup. It has been my thought that anything less would waste the image circle of my 645 lenses. And please keep in mind, I have many 645 lenses at this point (a total of eight to be precise). Of all the photographers who are currently or have previously been heavily invested in film gear, this is a pretty normal situation. That is to say, when film gear was cheap, it was difficult to say "no" to a new lens or anything else when you see a piece of gear show up at the local shop or on KEH.
Even if the above situation does not apply to you, you may still be happy to hear that medium format lenses are still in many cases less expensive than their new, manual focus counterparts intended for full frame cameras. As you may know, I am a big fan of employing vintage, manual focus lenses on my Sony a7R II — so much so that I still find myself shooting these lenses about half of the time. While it is true that you can find some really terrific lenses that meet this criterion and are cheaper than medium format options, they typically embody the shortcomings of vintage lenses without always offering other qualities to make up for those deficiencies. It is the "other qualities" that I just mentioned that I’ll be focusing on in this article as I believe that they are the reason you should at least consider shooting these lenses on your modern camera.
There are several strengths of these lenses that can essentially boil down to one thing: the larger image circle. For those readers that do not know what I mean, let me explain. Every camera lens, from those intended for sensors in our phones to those intended to expose an 8x10 negative (or positive!), there is an image circle cast onto the sensor or film which in ideal circumstances provides sufficient light and sharpness out to the corners of the image. In circumstances that are less than ideal, there can be heavy vignetting and a pronounced loss of sharpness as you move away from the center of the frame. It is here where the greatest benefit to medium format lenses is observed. That is, less vignetting when shot wide open and significantly better sharpness out to the most extreme corners compared with their full frame (/35mm) counterparts.
Inner rectangle represents 35mm/full-frame whereas the outer rectangle represents the 6x4.5 negative and the outer circle is the image circle
Let us take for example the above image which was made to convey this concept. The circle provides an example image circle that just covers a 6 cm x 4.5 cm negative. As you can see, the larger format is covered by the image circle but there is some vignetting and loss of sharpness as you move towards the outer edges. In this example, the smaller negative corresponds to the size of a full frame sensor (35mm negative). Given that the full frame sensor is so much smaller than that of a 6 cm x 4.5 cm negative, there is little to no vignetting and the center sharpness extends to even furthest corners of the full frame sensor. If you are a landscape photographer, this should be particularly appealing to you for telephoto lenses.
Left: full image, uncropped; Right: very most bottom left crop
Another strength is one that I personally have not taken advantage of much but would like to change that soon. Given the larger image circle of medium format lenses, you can easily use tilt-shift adapters. For mirrorless systems, there are very limited options for tilt-shift lenses and they are wide to very wide. If you open up to SLR lenses, there are more options, some of which are longer focal lengths. With that said, the least expensive option for any tilt-shift lens longer than 50mm is $1,399 (the Canon TS-E 90mm f/2.8 Tilt-Shift) which is considerably more expensive than buying a vintage medium format lens and a tilt-shift adapter (e.g., FotodioX Pro TLT ROKR Tilt-Shift Adapter).
There are still some pretty significant limitations to using these lenses which may end up making them less appealing to you, should you be on the fence about it at this point. Most importantly, unless you’re using a relatively modern lens, the vintage medium format lenses typically do not have coatings that can keep up with the best lenses today. True, there are some limited exceptions, and not all modern lenses have the same level of advanced coatings but still – overall, this is the case. Secondly, the medium format lenses tend to be pretty heavy and pretty large. Lastly, for some lenses, there is a bit of a reliance on the larger formats to do a lot of the heavy lifting when it came to sharpness. That is, not all of the lenses were not as sharp as some of their contemporaries because they didn’t need to be – when you’re printing an 8 x 10 or 11 x 14, there was such a big difference between 35mm file and 645 or larger than even a relatively soft MF lens would still result in sharper, better enlargements. Lastly, MF lenses tended to be 45mm or 55mm on the short end with most lenses being 80mm or longer which may not appeal to everyone.
This was taken with my 80mm f/1.9 which, as you can see, isn't the sharpest lens but it can still make beautiful photographs.
I have had some great luck with retrofitting medium format lenses on my Sony a7R II (my relatively inexpensive adapter can be found here) and I don’t see myself stopping anytime soon. In fact, I mostly digitize all of my negatives using my Sony with my Mamiya 120mm f/4 Macro A M lens. In addition, the Mamiya 150mm f/2.8 A remains one of the best lenses I own. The legendary Mamiya 80mm f/1.9 is a bit softer than the aforementioned two lenses but renders images in the most beautiful way such that I won’t stop using it either. When I get the chance to try out the tilt-shift adapter more, I will be using my 45mm and 55mm f/2.8 as well as the 80mm a lot. Should you have access to any medium format lenses, I highly recommend trying them on your digital camera – particularly for landscapes.