Alright Linhof, fess up! (GS film back adapter)

[abruzzi]

Did you actually make these or was it an idea that never came to fruition?

I have never seen one in my years of owning linhof 6x9 cameras (Including TK23S) and Bronica GS-1, and given that I have a GS with 4 or 5 backs, I would actually find something like this kind of useful. Has anyone see something like this in the flesh? It looks like it doesn't put the film plane in the exact same spot because it says a "focus corrector slide" was part of the package.

 

[abruzzi]

OK, after two year of thinking this was a impossible to find "Unicorn" I now have a brand new one. I'll use this thread I started two years ago to post some info on it to make the info available to others. I'll get some photos up soon, but first is the instructions were in german, and not english. this is a touch more complicated that I originally thought. I've attached a PDF scan of the two page instructions. Below is the english translation using google translate:

---

Operating Instructions for Back Adapter
Linhof / Bronica 001685

• Turn the transport wheel (1) until the hole (2) is visible. Insert the enclosed pin (3).
• Unscrew the transport wheel (1) counterclockwise and replace it with the enclosed transport wheel (4).
• First, hook the cassette into the two retaining plates (5), then press it down. It locks automatically.
• Unlocking and removing the cassette by pressing the button (6) is only possible when the cassette slide is inserted.

Film Advance with Adapter

Insert the film as usual and, with the cassette closed, turn the film advance knob (4) clockwise until the number 1 is visible in the window (7). The film advance will automatically stop. Press the lock button (8) before advancing.

---

Reviewing the instructions and the parts provided, replacing the Bronica wind knob with the Linhof one is not something you will change mid roll as it requires opening up the back. Turning the knob will as-is will work for me since the kit only provided once replacement knob and I have 4 GS backs. I might look at possibly 3d printing a larger knob, but for now I won't install the knob on any of the backs to see if the Bronica knob will be ok for general use.

Another thing not mentioned in the instructions is an additional piece. It is clearly a spacer meant to go where a film holder normally goes, under the ground glass. Unsurprisingly the mount doesn't place the film at the same plane as the ground glass so this piece pushes the glass back a couple millimeters to match. At least that is what I assume, since there are no instruction on using that piece. I expect I will be able to run a roll through this weekend. I'll make sure that one or two of the shots are focus tests.

One small issue I already discovered is that it doesn't fit the TK23S (and presumably the earlier TK23) in landscape orientation because of where they placed the button to release the Bronica filmholder from the back. To do landscape, you need to mount it upside down. Not difficult just slightly unexpected. I'll post of aphoto of this when I get a chance. My cell camera is dead at the moment so I'll dig up a camera to take pictures of the parts, but it might take a few days.

 

[abruzzi]

A quick point to add--the landscape issue I suspect is only a problem for the Technikardan because of its L shaped standards. I checked my Technika and it fits fine. Mine is a Technika III so I can't guarantee other models won't have an issue, but I don't expect that they will.

 

[mpirie]

So Unicorns do exist?

Did you get the adapter from Linhof or from the auction site?

How did you find out the adapter existed? Old Linhof documentation?

Mike

 

[abruzzi]

So Unicorns do exist?

Did you get the adapter from Linhof or from the auction site?

How did you find out the adapter existed? Old Linhof documentation?

Mike

I initially found out about the adapter from a Technikardan bruchure that had an array of the all the TK accessories in one large picture. There was no info except that photo plus a caption I found that two years ago, afterwards I spent some time looking and found almost nothing. (I did find a listing on KEH, suggesting that they had one for sale once.) My initial search did include a few emails to Linhof dealers, who didn't even know the item existed. I gave up, added some search notification to eBay in case one ever popped up.

A few weeks ago there was a discussion here about roll film backs for the baby technikas (which take the same backs the Technikardan 23 uses) so in a response I mentioned the GS back. That caused me to do a search to add some info to my post, but in the search I found a page from a dealer in Hong Kong that was clearencing out some Linhof stuff they had. They listed this item with some pitctures that suggeted they actually hade one. I emailed them and they actually had it for clearance proce of HK$680 (about US$90). So I wired them money and it arrived yesterday.

 

[mpirie]

Fantastic, your patience and persistence paid off, well done!

Mike

 

[reddesert]

Neat. I suspect that as a temporary-permanent hack, you could just stick a small handle onto the top of the Bronica back wind knob, using double sided foam tape, to make it easier to turn.

The larger Linhof knob may foul the Bronica GS prism if you try to then move the back over to a GS. I'm not sure of that, it's just something to consider.

 

[abruzzi]

Yeah, I will defintiely continue to use the backs on the GS-1, so whatever I come up with shouldn't make the back unusable on the GS-1.

So I took some photos to provide details. Some of the photos may look a bit wonky--I adjusted contrast to make things visible (photographing black on black loses a lot of visible detail, so the adjustments were to make distinguishing features clear.

First the box, with part number:

So here is the basic device. The Bronica backs have two hooks at the top you slide under the two silver pieces at the top, then pivot the base of the back down to lock the base. The protusion on the lower left (1) is the button to release the lower latches to remove the back. The lower mount also has to press a pin to allow removal of the dark slide.

All the 2x3 graflok roll film backs have a release somewhere to allow advancing to the next frame. The GS backs don't have this since it is normally handled by the camera body. On this adapter there is a big chrome button (2) that takes that function.

Here is a picture of the side that mates with the Linhof. Nothing much interesting here:

Here is a shot showing a back mounted:

I mentioned in a previous post that there is a piece that spaces the glass back to match the Bronica film plane. The silver headless screws are the actual spacers since they stick beyond the black frame on both sides. I didn't measure them yet, but they are in the ballpark of 3mm.

And the other side for completeness:

So I mentioned a fit issue in a previous post. The Technikardan uses L-shaped carriers. There is a piece (that moves with the frame, not the L that directly conlicts with the back release button (1) shown in the second photo above when in landscape orientation.

Here I tried to hold the back at the approximate position to see how they conflict:

The solution is for landscape to mount the back upside down. The has a weird benefit. If you've owned a GS-1 and other 6x7 cameras (I also have a P67), you probably know that most of them roll the film from left to right. This has the benefit that when you develop the film and cut the negatives, you have to flip the film to make the images upright, so the images read cronologically left to right, older to newer. Its the same with most 35mm cameras and other roll camera. The mostly roll left to right.

The GS-1 backs roll the film right to left. So when I shoot a roll develop and sleeve the film, if the images are upright in the sleeves, then I have to read the negatives chronologially from right to left. With the flipped back on the linhof adapter, I'm flipping the film when taking it effectively moving the film left to right, so when I sleeve a roll shot on the Linhof it will read chronologically left to right--i.e. normal for most of us. (as a drawback, if I shoot some frames on a single roll with the linhof, and some with the Bronica, then some frames will be upside down compared to others.

And of course there are no issues shooting in portrait. It could in fact mount in either orientation in portrait mode. The TK23 doesn't allow full rotation on any backs (not just the Bronica adapter), but in a Technika 23 you would have the ability to use portrait, landscape or any other angle you want since those cameras have no protrusions to stop rotation.

I'm still waiting for the weekend to give this a run through. I'd have been happier if Linhof made a 2x3 Graflok back, since I have a lot of horseman backs, and I prefer 6x9 over 6x7. The did make a 2x3 Graflok back for their 679 cameras (also works on the Techno I think). But I'm happy to at least have found this.

 

[itsdoable]

So... cool!