The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

adapting GFX 100S to Alpa with movement?

cuida1991

Member
Hello,
From the Alpa website, there's an adapter with which we can use GFX 100S as a "digital back" of Alpa. However, what's the limitation of this system, in addition to the lack of ability to focus at infinity for wide-angle lenses such as HR32, 43XL, etc? When using with longer lenses such as 90HR, 60XL, etc, does it allow full movement as long as the image circle allows? Has anyone tried this combo and how does it work?
Thank you so much in advance!
 

rdeloe

Well-known member
Imagine a hole in the ground with a mirror at the bottom. If you're walking towards the hole, there will be a point at which you can see the hole and not the mirror, then part of the mirror, and then the whole mirror.

That's the issue. The sensor in any GFX camera is deep inside a "cavity" (hence the 26.7mm flange distance of the system). Thus, there's a point at which the edge of the hole blocks the light path.

To illustrate, on my setup, I have several lenses that have enormous image circles that would allow vastly more shift than is actually possible with my 50R. The edge of the "hole" containing the sensor blocks the light path, causing a hard vignette. As a result, the maximum possible shift I can do is around 25mm, maybe 30mm depending on the lens.

Whether it's an Alpa or something else does not matter relative to this problem.
 

vjbelle

Well-known member
I believe (open to correction) that only a Fuji 50R can be used on an Alpa 12 camera. This is due to the fact that the grip is much more shallow than a 100s. There are lens limitations which exclude all of the wide angle lenses due to the distance of the sensor being too far from the FFD necessary to reach infinity.

If you want to use a 100s as a digital back I suggest you look into a Cambo Actus which allows full movements on all/most lenses 70mm and beyond.

Victor B.
 
True test by myself.

The Alpa adapter for GFX system is only for Alpa SB34/SB51 lenses, like Alpa HR50/90/138/180, or Alpa SK SB34 120AA/180/210/250.

And for GFX 100s, you can mount this adapter with the camera on 12TC/STC/SWA/Max, even Plus.

Test on 12 TC, it's no limitation, but no movement, of course.

12 STC, vertical/horizontal should be ok.

Test on 12 SWA, vertical side is ok, and horizontal side can be mounted, but the front dial button will be compressed and sticked to the back panel, due to the large grip.

Max is the same issue as SWA.

Test on 12 Plus, due to the newly structure design, you can not mount the adapter and the 100s on it directly , but can add a 17mm spacer, then with the adapter and 100s, and this way is ok for SB51 lens, so only HR 138/180 lenses are left for this combination.

And i believe GFX 50R should be ok on 12 SWA/Max with no front dial button issue, hoping Fuji will release a GFX 100R someday.
 
Top