Useable lenses for Horseman Woodman and 6 x 17 back

[mikestacey]

I'm just about to receive a 6 x 17 back for my Horseman Woodman and am

wondering if my present 90mm Nikkor SW F8.0 lens will work OK. It

seems like there may not be enough movement left in the standards to

get proper focus? Anyone had experience with this?

[leonard_evens]

The Nikor 90 mm f/8 lens has an image circle of 235 mm. That should be more than enough to cover the diagonal of the 6 x 17 format, which is under 180 mm, including a reasonable amount of movement.

 

I'm not sure what the question is about focusing. If you can focus now, you should still be able to focus even with the new back. But perhaps I don't understand which camera you have. The Horseman Woodman 45 is a 4 x 5 camera and I don't see how it would accomodate a 6 x 17 back.

[michael_briggs2]

There is a new 6x17 roll film back that positions the film well behind the position of the 4x5 ground glass. With many lenses, the light can pass through the 5 inch gate and still cover a 17 cm length, because of the greater depth. But it means that it impossible to focus really short lenses because you have the minimum separation of the standards plus the depth of the back. There was an article in View Camera magazine that reported on this back and usable lenses -- also some previous posts here.

[michael_briggs2]

<p>One post the way the 6x17 back works, and usable lenses, is buried in this thread: <a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00B0d6">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00B0d6</a>. Kerry Thalmman estimated that the shortest usable lens would be from 75 to 90 mm, depending on camera, which doesn't answer the specific question about the Horseman Woodman. Mike, perhaps you could report after you receive your back and try it out?</p>

[mikestacey]

Thanks Michael for your input. Your right, the problem is the fact that there may not be enough rear movement along the rails to get good focus due to the extra 47mm for the film plane of the 6 x 17 back. The back should arrive soon and I will repost here with all the info about wheteher it works or not. Meantime I'll scour the threads here for more info.

 

Thanks again.

[michael_briggs2]

Is the extra depth 38 or 47 mm? From Kerry Thalmann's article in View Camera magazine, I thought it was 38 mm. You could make an advance estimate of whether the back will work by focusing your 90 mm on infinity with the 4x5 back, then measuring and seeing how much closer you can move the standards together, after removing the 4x5 screen as if you had installed the roll back.

[mikestacey]

Yes you're right Michael, it's 38mm. I was reading about a different one that had 47mm, can't remember, it may have been the Shen Hao? Anyway it looks like I can get the front standard no closer than 75mm from the ground glass meaning, with the 6 x 17 back installed, I will have a minimum distance of 75 + 38 = 113mm. This wont be enough to focus the 90mm lens to infinity I don't think. I'll need a recessed len panel with about 25mm of recess. Does this all sound correct to you?