Shen hao 617 Filmback Lightleaks

[Emanuel Schi]

Hello everyone,

About half a year ago, I bought a used Shen Hao 6x17. Since the beginning, I’ve occasionally had issues with light leaks. Unfortunately, my most recent roll was so badly affected that I really need to find a solution now.


I always remove the darkslide completely from the holder, and I’m careful when advancing the film to avoid exposing the window to direct sunlight. Strangely, on the same roll, some photos are perfectly fine while others—taken just a couple of minutes apart—show light leaks running from left to right.

Any tips or suggestions would be greatly appreciated!

Thank you

 

[Emanuel Schi]

Pictures taken 2 minutes apart:

 

[MTGseattle]

Sorry. Is this regarding the purpose built 6x17 camera or the Shen Hao 6x17 roll film back? If it's the back, does it seat tightly and/or lock securely to your camera? Is there any slack in the graflok or other style clips that hold the accessory backs in place?

 

[Emanuel Schi]

I have the purpose built 6x17 camera. With the matching film back. The back sits pretty tight.

 

[djdister]

I recently bought a new TFC617-A but sent it back because it had a slight light leak (not as bad as yours) between the camera and the film holder. With the film back on there was just a little bit of play between the film back and the camera back - I could push in the back just a bit when it was fastened on the camera, but I could not find any way to tighten it and did not want to add new light seal foam on a new camera body.

 

[Emanuel Schi]

I recently bought a new TFC617-A but sent it back because it had a slight light leak (not as bad as yours) between the camera and the film holder. With the film back on there was just a little bit of play between the film back and the camera back - I could push in the back just a bit when it was fastened on the camera, but I could not find any way to tighten it and did not want to add new light seal foam on a new camera body.

Hmm, I might need to check that again and maybe add some foam The film back I have only has something I can call "black fur" on the edges.

 

[Dan Fromm]

I always remove the darkslide completely from the holder,

Don't.

 

[MTGseattle]

The "black fur" should be felt strips and is pretty common as light seal material in cameras. There are multiple sources for the appropriate stuff. 3M 300LSE is one type that is used in some kits.

 

[djdister]

Don't.

Dan,

Are you advocating to never fully remove the dark slide in all cases (including typical 4x5 and 5x7 film holders), or just in the case of the Shen Hao film back as in this specific case?

 

[Dan Fromm]

Dan,

Are you advocating to never fully remove the dark slide in all cases (including typical 4x5 and 5x7 film holders), or just in the case of the Shen Hao film back as in this specific case?

All cases. Remember that the film holder's gate will be fully exposed before the dark slide is completely out. Since that's the case, why take chances?

 

[djdister]

All cases. Remember that the film holder's gate will be fully exposed before the dark slide is completely out. Since that's the case, why take chances?

I get your point. Adding to the issue with the Shen Hao 6x17 rollfilm back is that the end of the dark slide has this odd scalloped shape to it, instead of squarely cut like normal sheet film holders. I wonder why they did that?

 

[Dan Fromm]

I get your point. Adding to the issue with the Shen Hao 6x17 rollfilm back is that the end of the dark slide has this odd scalloped shape to it, instead of squarely cut like normal sheet film holders. I wonder why they did that?

No idea.

 

[Besk]

When the darkslide has been completely removed and is reinserted back into the back it contacts the felt not all at once. That reduces the stress on the felt/back interface (which is glued into place )and reduces the chance of the felt being torn from the holder.

Not the first time I have seen this.

 

[djdister]

So here's a comparison between the darkslides of the Canham 6x17 automated rollfilm back and the Shen Hao NSH617 rollfilm back. I've never had a problem with the Canham 6x17 RFH, even removing the dark slide entirely for each shot, whereas I've had minor light leaks (between the frames) at the end where the darkslide comes out with the Shen Hao back.

 

[reddesert]

Many roll film holders have slightly scalloped ends of the darkslide. For example, Mamiya RB67, Mamiya Press, and (slightly less scallop) Bronica ETR and SQ. It's presumably for easier insertion. For example, https://ianbfoto.com/product/mamiya-rb67-dark-slide-3/

I don't have any experience with the Shenhao 6x17 back, where there is an issue, it might have to do with the design of the light trap, but the darkslide end shape is not prima facie flawed.

 

[djdister]

Many roll film holders have slightly scalloped ends of the darkslide. For example, Mamiya RB67, Mamiya Press, and (slightly less scallop) Bronica ETR and SQ. It's presumably for easier insertion. For example, https://ianbfoto.com/product/mamiya-rb67-dark-slide-3/

I don't have any experience with the Shenhao 6x17 back, where there is an issue, it might have to do with the design of the light trap, but the darkslide end shape is not prima facie flawed.

Thanks. I got out my Horseman 6x12 back yesterday and was surprised that it's darkslide was scalloped very much like the ShenHao back, so I guess Mr. Canham's 6x17 darkslide is the exception for rollfilm backs. I do think the ShenHao light trap/darkslide "slot" is a bit wider than other rollfilm holder slots.