Options for 6x17 backs on 5x7 cameras?

[Michael Mutmansky]

Folks,

I'm looking around to find out what my options are for 6x17 backs that will fit 5x7 cameras. I'm not interested in the 4x5--->617 adapter backs as these pose too many compromises for what I would like to do.

I'm aware of the Canham, the Horseman and the Shen Hao backs. Are there any other options out there?

I'm familiar with the operation of the Canham, and use similar 6x9 Horseman backs so those should be no surprise. I have no experience with the Shen Hao or similar backs, but I have used red-window film advance in the past, so that should not be a problem. Are there any users of the Shen Hao out there that can specifically address what they like or dislike about the back?


Thanks,


---Michael

[Nick_3536]

I just got the SPC617 with my Shen 8x10. I haven't had it long enough to have any dislikes or likes really. The red window is lighter then my older 612 back. I did a worst case test with some 120 film that has black backing paper. I managed to load it just fine. I can't really do that with the 612 back. With more common 120 film I'm thinking loading etc will be even easier.

Is there any thing in particular you want me to check?

[Michael Mutmansky]

Nick,

I guess I'm interested in whether the light trap works properly, and whether the body is made well enough to avoid light leaks anywhere along the seams. If I were testing the back, I'd place it in the direct sun at different angles to see if it gets any penetration into the film. Especially when the darkslide is pulled.

That's the rigorous kind of test that would tell me how much the back needs to be babied to avoid leaks. If the Shen Hao back is a well designed back, it won't show any problems under normal operation. I can live with some cosmetic issues, but functional issues would be a problem for me. That would eliminate it from consideration.

---Michael

[Nick_3536]

If I leave it mounted with the dark slide pulled doesn't that end up being a test of the bellows eventually?

It's a three piece back. The outer shell is two pieces plus the internal bit. There is a fair bit of metal around the thing.

I've had it loaded with film in normal room light for quite a while now. If I can find the time I'll mount it on the camera and leave it the rest of the week before firing off the four frames. I really need to do that but have been too busy. No promises but I'll try.

[Ken Lee]

Just a thought: You could cut up a dark slide, and get 2 images per 5x7 (if my calculations are right). That would allow you to develop sheets independently, to control contrast, etc.

Another, slightly more expensive thought, is that you can currently mask your 5x7 back any way you like, with some simple blue painter's tape, to give you any ratio you like: 3 x 7 inches (http://www.kenleegallery.com/html/gallery/daffodilswide.htm), 2.6 x 7 inches (http://www.kenleegallery.com/html/gallery/amarwide.htm), 4x7.. etc.

The money you save by not buying a holder, along with the greater visual flexibility, might balance out the cost of shooting 1 sheet per shot.

[Nick_3536]

From the factory the 6x17 holder is about $350ish IIRC. The main reasons I think for the roll film holder is colour film. Plus the ease of processing 120 versus 5x7. IIRC I think some body commented that the pay market liked 6x17 more then some of the other formats.

[David A. Goldfarb]

I use the half-darkslide option on 8x10", and it can work if your camera has sufficient rise/fall (and shift for verticals) and if the bellows is amenable, but an attraction of a rollfilm back is that it's centered in the normal viewing field, so you don't need such extreme rise/fall to get a centered image.

[Michael Mutmansky]

Nick,

With the darkslide pulled, it will be a test of your camera if there are leaks, but it will also be a test of the lighttrap in the darkslide area, which is what I am interested in.

Ken,

I don't intend to shoot much 5x7 with the camera, mostly 4x5 Quickloads, so I'm not interested in the half-darkslide options. Besides the problems getting film emulsions, there are issues with centering the effective area when using a split darkslide. While I can see that approach for an occasional user, that's not my idea of a good time when wide format is intended to be used a considerable amount.


---Michael

[Nick_3536]

Nick,

With the darkslide pulled, it will be a test of your camera if there are leaks, but it will also be a test of the lighttrap in the darkslide area, which is what I am interested in.


How long? If the weather is okay this weekend I can likely set it up in the garden for a bit. Unless it rains

[Michael Mutmansky]

Nick,

Probably only need to test for a few minutes. The extreme test would be to have the DS pulled, and have the sun almost directly aiming down the DS slot. Leave that for 5 minutes or so, and you'll know if there's a leak in the DS light trap or not. In most cases, you can protect the slot with the focus hood, but it is nice to know it it's even necessary to go to that measure.

Think about the situations where you pull the DS and then have to wait for the wind to die down or something similar. In those times, the holder is somewhat susceptible to light leak problems. That's the kind of testing I will generally do, except a bit more extreme so that any issue can be readily seen in the test sheets/roll.

Any chance you can take a handful of good shots of the holder? The two images I've seen are not terribly instructive to how well the holder is made or functions.


---Michael

[Nick_3536]

The only digital thing I have is the scanner -)

On mine the only cosmetic issue is the leatherette. The guy who glued it didn't hold it down in a couple spots. So the leatherette is peeling. Considering I'm not a fan of leatherette that might be a bonus. It seems well machined.

Loading was pretty obvious. Nothing fancy there for anybody that has loaded a MF camera before. To mount you remove your 5x7 graflok back and put the rollfilm holder on. I don't know if the other camera makers using the same fitting. How standard are 5x7 graflok backs?