Fuji/Fujica GSW cameras -- question

[rdeloe]

Rob, the 50mm and 210mm lenses were later additions to the Mamiya 7 lens lineup, coinciding with the introduction of the 7II.

That's why that first chart omits them.

Ah, that makes perfect sense.

Someone out there probably has the 210mm chart in paper form, but I've never seen it in the wilds of the Internet. I'm quite keen to try this one because I want something a bit longer than my 150mm, but small and light. I have lenses in that focal length range but one is a monster (Pentax 67 200/4) and the other is still bulky and only OK (my re-housed Fujinon GX 210mm f/5.6).

 

[wallpaperviking]

I promised a quick report on the Mamiya L 65mm f/4...

It's early days with the lens I chose for 65mm -- the Mamiya L 65mm f/4 -- but so far I'm very happy with the choice. Bill Rogers from Mamiya Repair in Nevada locked the shutter open and removed all the extraneous bits I don't need.

My plan was to replace the Mamiya 7 lens mount with a Mamiya 645 mount I scavenged from an extension tube set. I already built the Mamiya 645 recessed lens board for my Arca-Swiss F-Universalis while I was waiting for the lens. It turns out that Mamiya re-used the basic design of the Mamiya 645 mount. A Mamiya 7 lens with all the electronic bits and levers removed will fit nicely on a Mamiya 645 extension tube mount with all its extra bits removed. The mount designs are not exactly the same, so the Mamiya 7 lens sits a bit loosely unless the springs in the mount are tightened. That was quick and easy, so now the lens mounts snugly.

Public Service Announcement: Please don't try to put an unmodified Mamiya 7 lens on a Mamiya 645 camera. You'll wreck one or both!

Best of all, this copy has a buttery smooth focus ring. The older Mamiya G lenses I use have stiff focus rings due to dried grease, which doesn't bother me because I only use them on digital view cameras where I focus by rail. I was hoping the 65/4 would have a good focus ring because I was looking forward to making a direct-to-GFX mount for it.

That mount project took a bit longer, but also worked out well. The combination of the GFX to M65 adapter, M65 helicoid and Mamiya 645 mount from an extension tube come just shy of the exact length needed for infinity focus. I'd rather be under than over, so this is ideal. Plus I now have a close focusing Mamiya 7 65/4. With its own helicoid, it only focuses down to around 1 meter, but with a bit of extension from the M65 helicoid when needed, I can focus to around 30 cm.

I won't comment much here on image quality because it's early days. I need to use a lens a lot before I feel confident about image quality. I can say that so far it seems excellent and I'm not seeing anything I didn't expect. For instance, the published MTF data gave me a head's up that the centre would be excellent at f/4, and the edges a bit soft, but by f/8 it would be excellent across the GFX frame. And that's exactly the case. I was also expecting 20mm of good quality shift in landscape because the lens was designed for 6x7 film, and that too is the case.

View attachment 200762
Mamiya L 65mm f/4. Top is on a direct-to-GFX adapter, and bottom is on an Arca-Swiss F-Universalis. Both adapters use a custom Mamiya 645 mount (which is an almost perfect fit for a 'stripped down' Mamiya 7 lens).

Rob, you are a pioneer! Good work!

Would this modification work on any of the wider Mamiya 7 lenses? Would the BSI of the 100S mitigate the colour cast and/or smearing?

Thanks!

 

[rdeloe]

Rob, you are a pioneer! Good work!

Would this modification work on any of the wider Mamiya 7 lenses? Would the BSI of the 100S mitigate the colour cast and/or smearing?

Thanks!

I think the word you were looking for was "lunatic" rather than pioneer!

I don't know for sure if this would work with the 50mm and 43mm lenses. I say that only because I haven't tried. However... I've studied them from pictures, and I don't see why not. But there's a huge "but" here. Both have long rear lens groups that project well beyond the flange. If you're not planning to shift or tilt the lens, that won't matter in terms of the mechanics of the mounting. If you are shifting, before you put your money down you should calculate how the rear of the lens will interact with the camera. For example, on my F-Universalis with Rotafoot and GFX camera, these lenses are pointless because they will be inside the Rotafoot. That's a shame because based on what I'm seeing in the MTF charts, they look spectacular.

As to the colour cast issue, again, I haven't used the lenses, and I don't have a 100S. I have seen a sample full resolution image with the 43mm on an older Phase One back. There was colour cast. I haven't seen a sample from the 50mm for Mamiya 7, but I would expect colour cast because the light is coming out the lens very close to the sensor. I think it should be reduced at least on a BSI sensor like the one in the 100S, but I have no personal experience with that.

This is where the Mamiya G 50/4 really wins for me. Not only is the rear lens group much smaller, which means it clears the Rotafoot and allows as much movement as the image circle permits, but also there's no colour cast on shifting on my GFX 50R until you get outside of the image circle that covers 6x6. When I bought the lens, I had to take the chance that there would be colour cast even with small shifts because the changes made to the lens were not reversible; it was either a great lens, or a cautionary tale paper weight. I was delighted that it performs so well. The G 50mm for Mamiya 6 has no faults that matter to me, and only strengths, so I'm not concerned that I can't use the Mamiya 7 50mm.

Hope that helps.

 

[wallpaperviking]

Yes, thanks so much! Love ya work!