The Fujifilm GX617 is a manually operated camera with a leaf shutter in the interchangeable lenses.

There are two ways for firing the shutter

  1. Via cable release connected directly to the lens' leaf shutter
  2. Via the shutter button on the body (which electromagnetically fires the same leaf shutter).

The electromagnetic shutter release is powered by two CR123A batteries. According to here and this review here the batteries are used solely for the shutter release, and according to the first link can't be used for Bulb releases. Just read a PDF of the manual here, and it says (on page 11):

enter image description here

There is no in-camera metering or anything electronic at all, and according to reviews I have read I believe that the camera can be operated without the batteries.

But if you look at the body of the camera (image taken from the review mentioned above, but red box added by me), there seems to be an inordinate number of electrical contacts on it. This seems to be far more than required to simple trigger the shutter.

enter image description here

Why would there be so many contacts?

I can imagine that it needs:

  1. Ground signal
  2. Shutter release command
  3. Sense that the lens is not in Bulb mode

But that doesn't explain 6 contacts.

  • \$\begingroup\$ Is it possible an autoexposure, or at least open-metering system was intended in another body at one point? It would make sense to transfer aperture information over additional pins since there seems to be no linkage for that. If I recall at least one MF SLR used a set of electrical contacts to indicate max aperture. \$\endgroup\$
    – davolfman
    Commented Jun 17 at 17:36
  • \$\begingroup\$ @davolfman This camera is more akin to a large format or medium format camera that takes sheet film. It wouldn't make sense to me to transfer information that wouldn't be used. \$\endgroup\$
    – Peter M
    Commented Jun 17 at 17:52
  • \$\begingroup\$ @Peter_M a moot point since there's an answer. I was mostly speculating that if they had planned another model that somehow crammed a meter in there (by a pellicle mirror or something), you'd need aperture info to do anything more advanced than stop-down metering. \$\endgroup\$
    – davolfman
    Commented Jun 17 at 20:30

1 Answer 1


I have an original sales brochure for the GX617, and this is explained in the brochure.

scan of sales brochure

Lens/Body connection

There are six electric connectors, which comprise 2 banks of 3 connectors each. If one bank fails to operate, the remaining bank automatically begins to operate. This results in a stronger, more reliable product.

  • 1
    \$\begingroup\$ In other words, Redundancy. \$\endgroup\$
    – Michael C
    Commented Jun 18 at 8:55
  • 2
    \$\begingroup\$ @MichaelC Or it could be marketing speak used to cover up the fact that at the time Fujifilm could only source electrical contacts that came in pairs. It should simply be two contacts wired parallel. The use of "automatically" in the quoted text smells greatly of BS to me. \$\endgroup\$
    – Peter M
    Commented Jun 18 at 13:00
  • \$\begingroup\$ @PeterM If that were the case they could have gotten away with using only two pairs and left one contact unused. Notice they said two banks of three, not three banks of two. \$\endgroup\$
    – Michael C
    Commented Jun 20 at 1:24
  • \$\begingroup\$ @MichaelC It all depends on the parts that were available at the time, the cost of them, what the semantics used to describe them were, and the issue they were trying to solve. Yes, the mechanical and electrical configuration of the contacts is redundant. But if at the time they could only source such contacts in pairs, then I'd be looking for ways to play that up myself. You also have to consider the language the sales brochure was developed in. A native English speaker will phrase things differently to translated Japanese. And some of the other language in that brochure is awkward. \$\endgroup\$
    – Peter M
    Commented Jun 20 at 13:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.