4x5 readyload in 4x10 camera

[jetcode]

if I use a black plastic bag or focusing cloth to cover the ground glass of a 4x10 do you see why there would be any reason a 4x5 sheet in a ready-load would not expose properly?

thanks,
joe

[Kerry L. Thalmann]

Joe,

Whether this would work depends on the camera. Assuming you can get a good light tight seal and prevent any stray light entering from the back of the camera (not a trivial task), there is also the issue of the t-distance.

Most 4x10 cameras are built to the Canham film holder standard. The one exception is the Wisner, which was based on some old, long discontinued and nearly impossible to find 4x10 x-ray holders. The Canham holders are made from 8x10 parts Keith gets from Fidelity. So, they have the same thickness (0.594") and t-distance (0.250") as standard 8x10 holders. They are also wider (5.312") than 4x5 holders (4.765") due to the larger 8x10 components. Think of them as skinny 8x10 holders.

The x-ray holders Wisner based his camera on could be thought of as long 4x5 holders. They have the same width (4.765"), thickness (0.520") and t-distance (0.197") as 4x5 holders - they're just longer.

So, what this means is unless you have a Wisner 4x10 camera that hasn't been modified to take Canham style 4x10 holders, not only will you have problems with potential light leaks, you also won't be focusing on the correct plane. A 4x5 reducing back would be a much better, trouble free solution.

Kerry

[jetcode]

Hi Kerry,

Thanks for that answer. I just purchased a Shen-Hao 4x10 which takes Canham style holders. Assuming I can get a light tight fit is it possible to adjust the focus by the differential of the t-plane, i.e. compensate for the focal t-plane difference?

Thanks,
Joe

[Kerry L. Thalmann]

Joe,

Assuming you can get a light tight seal - not a trivial matter given that the Reayload holder will be shorter (obviously), thinner (front to back) and not as wide (side to side) as the 4x10 Canham style holders - you could potentially move the rear standard forward 1.3462 mm to compensate for the different t-distances after focusing on the ground glass. Do you think you can achieve this level of precision on a consistent, repeatable basis with your Shen-Hao? Will you remember to do it every time? If not, you may end up with a lot of images that lack sharpness due to slight focusing errors.

Also keep in mind the image area will be shifted all the way to the right end of the GG. This means you'll be using the edges your lenses image circle, rather than the center sweet spot. You might not notice this on the film, and maybe not on the prints unless you make big enlargements, but lenses perform better in the center than at the limits of their coverage. You will also have less IC left over for movements since you've already introduced 2½" of shift by placing the 4x5 film area all the way to one side of the 4x10 opening. It looks like you could get part of this back by shifting the front standard all the way to the right. Too bad there is no rear shift on the Shen-Hao as that would have allowed you to center your lens on the 4x5 image area of the Readyload holder. This probably isn't a show stopper, as most of your lenses will cover 4x10 anyway, but could prevent you from using shorter wide angle lenses with smaller ICs on the 4x5 format.

Since your Shen_Hao has a removable back, why not just make a 4x5 reducing back for it. If you pick up a 4x5 back on eBay (Speed/Crown Graphic backs are plentiful, but Cambos and Toyos also show up regularly), all you need to do is make a wooden rectangle of proper dimensions to fit the back of your camera. You can make this out of plywood, or you can get fancy and use walnut (or stained pine) to match the finish of your camera. This would give you a back that centers the 4x5 image area relative to the lens position, would automatically address the problem of getting a light tight seal around the Readyload holder and would place the GG in the right position for proper focusing. It would also allow you to use roll film backs, a Polaroid holder, possibly a reflex viewing hood, etc. From the photos I've seen of the Shen-Hao 4x10 it looks like the back is of sufficient size that you could even use a rotating back (like Toyo or Cambo) as the basis for your reducing back. This would allow you to shoot 4x5 vertical images without turning the entire camera on its side.

Kerry

[jetcode]

Hi Kerry,

I was thinking of carrying a precision measure that goes to 4 places when measuring millimeters, along with a big bottle of aspirin. It might work maybe, but is far more hassle then loading 4x10 color film and shooting that. Now I have to see if I can locate a lab to cut some color film for me because I surely don't want to do it at this time. Anyone think of starting a film cutting service? I'm sure someone could make some money keeping people in fresh cut film. Thanks again for your ever so valuable advice and knowledge. If you ever teach a workshop let us know. My guess is that my entire vocabulary of LF experience will never be the same.

Take care,
Joe

[Nick_3536]

It's not colour but Fotoimpex shows 4x10 film last time I checked their website.

Why not try cutting paper first? 4x10 is just one cut not that scary.

[jetcode]

Problem solved! Shen-Hao is making me a 4x5 back for my 4x10 for $195. I just ordered the camera and it's coming in Burma Teak.

[C Henry]

Jetcode,

Will the 4x5 reducing back be constrained to one orientation?

As that is the way the 5x7 reducing back works on the 410 camera.

[jetcode]

Jetcode,

Will the 4x5 reducing back be constrained to one orientation?

As that is the way the 5x7 reducing back works on the 410 camera.

Yes. The camera is light and can be rotated in a tripod. While certainly not as convenient as a rotating back it will be consistent with all verticals for this camera.

[C Henry]

The only drawback is that the front swing and shift are controlled by the same lever (under the standard), which is fine and dandy when the camera is horizontal.

When composed in portrait format and one wants to include 'front tilt' (with the swing), the shift invariably will frustrate the precision of focusing..... unless there is another method.