Some love for the Fuji GX680III so big!

[Martin Konrad]

Thanks!!!

 

[Nokton48]

Std Maki 120-125mm lens group by Nokton48, on Flickr

A Duo of 125mm GX680 lenses on my Makiflex Standard The one extreme left is the HOT 125mm F3.2
On right is 120mm f6.8 Schneider barrel Angulon. On Maki is the 125mm F5.6 GX680. Low priced lens very good!

Plaubel Peco Jr recessed boards fit inside the Maki Standard. Will not fit my Maki Autos. The GX680 Finder completes the Maki Std

 

[Martin Konrad]

I read through all 20+ pages of the Makiflex thread yesterday regarding the GX680 lens conversions.
I was hoping the lever next to the lens was a manual aperture lever which would have been a lot easier...
Waiting for the first lens to show up to see what can be done but sourcing Seiko shutters is going to be the
most annoying part of the project.
How did you establish the corret distance between the two lens elements, or did they just screw on the shutter either side
and your are done?
I wonder if lens adapters with buid in aperture could work, they are easy to find.
Do you have the seiko 1 diameter? some sellers only go as far as "seiko shutter + screw size"

thanks

 

[Nokton48]

I have bought broken RB67 lenses which contain the correct Seiko shutter to directly screw in front and back. No additional collimation; mine seem to work OK so far. Electrical contact tabs (look at the close ups) can be attached to even the stock electrical shutters with JBWELD metal epoxy. If I remember correctly I was buying bad glass ugly 250mm f6.7 Fuji. I think it was the WS lenses I would look at the auction pictures and compare the photos there are different versions so be careful. A couple of lenses are still in the original electronic shutter I was able to carefully remove the shutter blades completely, the iris will still function. I'm not done, I need more Plaubel Peco Jr recessed lensboards. I'm still looking for the 115mm F3.2

 

[grat]

If you're electronically inclined, there are service manuals for the GX680 on learncamerarepair.com. Included in there is a wiring diagram, and signal information on how to control the shutter via the contacts in the lens. Shouldn't be hard to wire up an Arduino to control the shutter (at which point the aperture lever would be functional).

 

[Martin Konrad]

so do I understand that right, the lever next to the lens operates the aperture but needs power supplied by the camera?
In that case there would be a chance to make a lens board with a battery to supply power via the contacts.

 

[grat]

That's the theory.

 

[Danner]

On the other hand, I would never replace my smaller 6x7cm Mamiya RB67 for a larger 6x8cm Fuji GX680.


Saanich-20120407-00050 by John Roberts, on Flickr

That's quite telling. Would be interesting t see a Bronica GS-1 in there too. The RB67 makes the Bronica look small.

 

[itsdoable]

The stop-down lever on the GX lenses are mechanical, the aperture closes mechanically when you close the lever. It is spring loaded, so it returns to full open when you release it. If you remove the spring, it may stay closed. No power is needed to stop down the lens.

 

[Ernst-Jan]

View attachment 233534
And another quick shot : Sky under the stairs - Fuji gx680iii 100mm f4 6x8 film - Kodak portra 400.

What a detail! How did you scan those?
The Fuji GX680 looks very tempting, but nah, it's not really a "walk around" camera, the RB67 is already big enough for that...

 

[Martin Konrad]

The stop-down lever on the GX lenses are mechanical, the aperture closes mechanically when you close the lever. It is spring loaded, so it returns to full open when you release it. If you remove the spring, it may stay closed. No power is needed to stop down the lens.

Thanks for your response!
I got an 80mm today, so effectively there are two levers, one for aperture another to stop down.
So all I have to do is blocking the stop down lever.
I probably won't attempt any lens surgery, I am worried the plastic housing holds the lever mechanism in place, I might be better off getting an Arca board with a GX lens mount and leaving the lenses as they are.
I will update if I get closer.

 

[Martin Konrad]

If anyone has a broken GX680 I am happy to buy it of you, only need the front plate to make a lens mount!