I just completed a series of quick tests mounting a bunch of Pentax FF glass to my new Fuji GFX-50R and thought I would share my preliminary results here. Not posting pictures because they were all handheld high ISO low quality jpg shots just to figure out which lenses might work on the GFX platform. I did not test all apertures, just wide open, a mid-range or two, and stopped down. The good news is all but one appear to be useable at least in some parts of the range. I was surprised that in the shorter focal lengths vignetting was more pronounced wide open than at the smallest apertures. I will try to post more detailed reviews with pics in the forum as I learn more about how these lenses work on the GFX.
Here’s the quick rundown of what I found:
Near full coverage – mild to no vignetting at all apertures: FA 43 Ltd f/1.9; FA 77 Ltd f/1.8; 85 Soft (original version); SMC-M 100 f/4 Macro; SMC-M 200 f/4; Lensbaby Composer,
Very useable – some dark vignetting in corners at extreme apertures, but easily cropped and goes away as you move away from the extremes: FA Ltd 31 f/1.8; SMC-M 50mm f/1.4; SMC-A 50 mm f/1.7; FA 135 2.8
Somewhat useable – dark corners at all apertures but still has significant useable coverage: FA 24 f/2.8, Laowa 12mm Zero-D f/2.8 (with hood removed), FA* 300 f/4.5, Tamron 70-200 f/2.8 (better at longer focal lengths)
Unuseable – Full circle requires crop to near 35mm form factor – FA 20 f/2
A couple notes on adapters. The prior posters probably know this already, but leaving this for the next newbie GFX shooter that comes along
:
You need to enable “shoot without lens” in the GFX menu for them to work. Took me a while to figure out where that was hidden (the Fuji menus are not nearly as logically labeled or laid out as Pentax).
All of the adapters are dumb, in that they don’t transmit any information between the lens and the camera; no AF, aperture control or EXIF info. Through a combination of ignorance, impatience and dumb luck I ended up with three K-mount to G-mount adapters – the AF and Regular adapters from Fotodiox and the adapter from K&F Concepts. Out of the box I preferred the K&F adapter to the others. All fit pretty snugly, but K&F uses the standard lens release button on the Pentax side that we are all familiar with, while Fotodiox uses just a metal pin that you have to press on. The K&F seems to go on a little smoother as well, and is much cheaper than the others. Be forewarned, however, that they are slow to ship and do not respond to most customer inquiries about order status. They did not mark it shipped until after I initiated a refund request, and did not actually ship it until after I opened a paypal dispute. YMMV.
All of my tests but one were using the K&F adapter, though I expect the Fotodiox will perform the same. I tested the Tamron using Fotodiox’s autofocus adapter because it lacks an aperture ring. Despite the name and the hefty price, that adapter does not permit the lens to AF; it just has an extra metal ring that provides 8 stops of aperture control for modern AF lenses that do not have aperture rings. It was shipped to me by mistake after I figured that out and cancelled the order, so it is going back. Being able to test it confirmed that I don’t need it because the glass I want to use all has aperture control rings.
Last edited by EstimatedEyes; 05-12-2020 at 01:39 PM.