Prototype box camera

[Dan Fromm]

When I made mine out of cigar box, I didn't even consider keeping lens stage exactly parallel with the film stage...I am to stupid to live.

I'm not sure about that. You certainly aren't paralyzed by perfectionism.

[Jac@stafford.net]

I'm not sure about that. You certainly aren't paralyzed by perfectionism.

So true. I know how crippling it is to be a perfectionist. Nothing is ever finished, but worse, it is never good enough.

'Adequate' is my mantra now.

[Randy]

Well, I can tolerate uniform softness, but out of focus on one side, sharp on the other is unacceptable. But I guess that will only show up if shooting the face of a building at wide aperture...I guess.

[Jac@stafford.net]

Well, I can tolerate uniform softness, but out of focus on one side, sharp on the other is unacceptable. But I guess that will only show up if shooting the face of a building at wide aperture...I guess.

Compromise is not necessary if you make the camera right.
.

[bobbotron]

When I made mine out of cigar box, I didn't even consider keeping lens stage exactly parallel with the film stage...I am to stupid to live.

I consider my camera to be a the holga of 4x5 cameras, I am not so concerned with this. :P I am having a heck of a time developing Arista 400 as anything but a muddy mess, but I can focus it now. Pretty happy with how my ground glass turned out.

[bobbotron]

This is a super neat idea, I like it Jac!

Make the box a little too short. Then cut straight through it. Place a large, compliant rubber/composite band around the slit. Using three 1/4" (or smaller) bolts and t-nuts on the outside; bridging the slit will give you a means to expand the band, adjust the back plane on three axis.

The bridge parts can be wood parallel to the slit, just large enough for T-Nuts on one side. A washer under the bolt head protects the wood. ROUGH DRAWING. Ignore scale.

Attachment 154855 j

[bobbotron]

Compromise is not necessary if you make the camera right.
.

I distinctly set out to make camera #1 without worrying about perfection, this was just a fun way to spend an afternoon and workout some basic concepts in my head. I have a lot of various wood and sheet goods, some more attention will be paid to camera #2.

[Jim Jones]

Unfortunately not, Dan. Shims only work when the rest of the standards is plan parallel. Therefore independent fine tuning of the OP's design works better. It is the common practical problem when building this kind of cameras - the box needs some means of continuous fine focusing at infinity, otherwise it's all a try and guess game. Amateurs often forget this point and come to it when all the measuring and cutting is practically inefficient.

What is more, even if you managed to build the box with its standards exactly plan parallel (almost impossible when the box is made with nails and wood) it is very impractical to measure the exact thickness needed for the shims. It's just a trial at best.
One who has been there and knows, yours sincerely, Pfsor.

Shims work fine. I suspect some very precise cameras with high speed lenses set infinity focus with shims. As for plane parallel sides to the box, a table saw with a true running blade and a firmly mounted fence take care of that. If the sides are cut a trifle long, after assembly the same set-up can take the box length down to size a few thousands of an inch at a time. Finger joints are great if one uses fine wood for the sides. Plywood, screws, and glue seem more logical although less elegant. Please, no nails unless you are a Holga fan.

[Pfsor]

I consider my camera to be a the holga of 4x5 cameras, I am not so concerned with this.

Shims work fine. I suspect some very precise cameras with high speed lenses set infinity focus with shims. As for plane parallel sides to the box, a table saw with a true running blade and a firmly mounted fence take care of that. If the sides are cut a trifle long, after assembly the same set-up can take the box length down to size a few thousands of an inch at a time. Finger joints are great if one uses fine wood for the sides. Plywood, screws, and glue seem more logical although less elegant. Please, no nails unless you are a Holga fan.

Sounds like someone paralysed by perfectionism
It's not that shims could not do the job. It's that measuring their required exact thickness is nearly impossible for an amateur and a guess and try approach doesn't work well when comparing sharpness on the gg with different shims used. Try it if you don't believe me.

But you know what? Make a camera yourself with the advice you give and tell us then how it worked. That's what I do. But first look at the screws the OP uses to assemble his camera box with before you start to look down at nails on Holga fans cameras.

[Jac@stafford.net]

Sounds like someone paralysed by perfectionism
It's not that shims could not do the job. It's that measuring their required exact thickness is nearly impossible for an amateur and a guess and try approach doesn't work well when comparing sharpness on the gg with different shims used.

Use aerial focusing rather than ground glass. The camera was all alloy, plane parallel, measured with good instruments. Of course it was easiest in this case because it was a sky camera focused to real infinity. To finesse focus to correct for different ambient temperatures, a fine focusing helix does the trick, although it's over-the-top.

But you know what? Make a camera yourself with the advice you give and tell us then how it worked.

After you, Sir.