Thickness of 6x17 Da Yi or Shen Hao rollfilm backs

[Roberto]

Hi all,
In order to find out if my Wista 45SP is able to accomodate a short enough wide lens (e.g. a 90mmm ) in combination with the 6x17 rollfilm back I need to know what is the exact thickness of the Da Yi (or Shen Hao) 6x17 Rollfilm back. I have googled a lot about this topic but did not find something accurate , other tan a "couple of inches" approximate indication . If indeed the back puts the plane of focus behind by 2 inches , then I won't be able to accomodate a 90 mm on my Wista (the wista can reach 65mm w/ a recessed lensboard hence the minimum focal lenght for infinity focus will be 115mm ).
Any help would be appreciated!
Roberto

[Jesper]

I think it will work with a 90mm but I will check that when I get back home.

Are you thinking about buiyng one?
I bought one from a guy who had only taken a few rolls with it. I got it and apart from the two test rolls I took I haven't had any use for it. It is simply too bulky to carry around and I need the same size of bag for that as I do for 8x10" (and then I have 25cm wide negatives instead).
Try borrowing one before you buy or you might end up like us.

Jesper

[Jesper]

The Da Yi builds 44mm, but the 4x5 back builds 5mm so the film will be 39mm further back than usual.
With bag bellows and recessed board you should be able to use a 90mm.
Hope this information is useful.

[Roberto]

Hi Jasper,
yes your info has been very valuable. I am not sure about the 90 (the 65mm figure is already considering recessed board) but at least the 110XL should be OK...

[Jesper]

If you look at the third lens board from the top at http://www.photax.se/kmrr/storformat...tikplattor.htm you will see the lens board that I meant (should be used with bag bellows)
With that combo you can use a 75mm lens with the Da Yi 6x17.

[karl]

On a flat lens board I find even the 110mm Super Symmar is challenge with the DaYi 6x17/Linhof Technika combo. The back seems best suited for lenses around 150mm. Though I do use a 210 with it occasionally.

With my old Canham DLC45 the 110mm was no problem.

Here are my shots with the DaYi 6x17 back:

www.flickr.com/photos/summicron2020/tags/da

[Roberto]

If you look at the third lens board from the top at http://www.photax.se/kmrr/storformat...tikplattor.htm you will see the lens board that I meant (should be used with bag bellows)
With that combo you can use a 75mm lens with the Da Yi 6x17.

Yeah I know that board. To be honest I never liked it, it requires bag bellows which means disassembling the rear part of the camera and replacing the bellows, a real pain...
In addition to handling the 6x17 back it means that the whole procedure becomes too awkward. But it is good to know that the solution does exist... thanks!

[David A. Goldfarb]

I posted about the DaYi 617 back when I had one. Check this thread--

http://www.apug.org/forums/forum186/...html#post98112