6x17 roll film holder on 4x5 cameras?

[Juergen Sattler]

I see these 6x17 roll film backs advertised on eBay all the time for 4x5 cameras - see below

http://cgi.ebay.com/ws/eBayISAPI.dll...875586025&rd=1

How is this supposed to work on a 4x5 back, where you normally only have a groundglass that's about 9x12 cm? What am I missing? There's addtl. 5 cm here - where would the illumination come from? When you look at one of the picture in the posting it shows how the gg of the 6x17 is attched and there clearly is significant illumination fall-off beyond the 12cm.

Juergen

[Diane Maher]

I didn't think you could use 6x17 on 4x5.

[Juergen Sattler]

That's exactly why I am confused. So is this guy just making it up to sell his 6x17 holders?

[David Van Gosen]

Maybe the adapter is thick enough to allow the extra film width? Can't really say from the photos.

[David Van Gosen]

Here's a thread that mentions the 6x17 back:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00B0d6&unified_p=1

[David A. Goldfarb]

It works like a 5x7" expansion back on a 4x5" camera. There is an extra groundglass viewer for focusing. You focus with the 6x17 groundglassviewer and replace it with the back to take the picture.

Obviously, you need lenses that cover the format, and many 4x5" lenses do, like the more modern 75mm lenses, 90mm lenses with the coverage of a Super-Angulon or better, and most 150mm lenses, and you might need a center filter with an ultrawide lens to reduce falloff of illumination, but that is a function of the lens and the format, not the rollfilm holder.

[Bob Douglas]

Juergen,

Not having seen one in person other than the pictures. It appears as the adapter unit has it's own ground glass and effectively moves the rear standard backwards. This could be a problem for wide angle lenses . You would need to study your camera and determine if the draw can be collapsed enough.

Since we are on the thread, Keith Canham Cameras makes a wonderful 6x17 roll film back for 5x7 cameras. It has a motor wind and a led frame counter. http://www.canhamcameras.com/Roll%20film%20back.html I own one and it's marvelously engineered. I wouild suggest trying to rent one first as it requires an additional degree of finesse in handling the camera since it does add weight to the rear standard.

[David A. Goldfarb]

When you look at one of the picture in the posting it shows how the gg of the 6x17 is attched and there clearly is significant illumination fall-off beyond the 12cm.

In that picture, I don't think there's a lensboard attached to the camera. You're just looking at the light coming through the front standard onto the groundglass, not an image formed by a lens, so it does not indicate anything about falloff beyond 12cm.

[David A. Goldfarb]

Here are two threads on this back:

http://largeformatphotography.info/l...98.html#538394

http://www.apug.org/forums/showthread.php?t=10112

There are a few different configurations (some have a monocular viewer in addition to the groundglass) and it seems various brands of Chinese 6x17 back, Da Yi (which seems also to be sold as Shen Hao) and KangTai (which seems also to be sold as "Art Panorama," but not to be confused with the Japanese Art Panorama camera).

[paul owen]

I've submitted an early impression of this back on this forum - http://www.largeformatphotography.in...hao-6x17.html. I have just returned from using this back with an improvised fresnel screen - VERY impressed!!