# How to hollow out squared off cone for 4x5 camera.



## Whimsy (Oct 14, 2011)

Hello all,

Long time lurker and hoping to get some advise on a small project.

I'm a beginning woodworker and am trying to build a small 4×5 camera. I am trying to figure out a method of carving the cone. The rough dimensions are 4.5"x5.5"x2" and possibly 1/4 " thick.















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I don't have a lathe and am not sure that the interior could be made on one anyway.Any ideas would be appreciated. Also, for different lenses different cone lengths would be needed so a repeatable adjustable method would be cool.

Thanks,

Gerald


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## yrob (May 26, 2008)

I would not carve it. I would make a box with the arcs on the sides. I would then take 1/4" (or less) wood and do I would steam bend that upper piece and glue it to the box. Finally cut the circle hole and the rabbet around it.
For a different lens, all you would have to do is add an extra box with square sides underneath to increase the distance to focal plane.


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## awsimons (Apr 26, 2009)

Is there an optical reason that this piece has to be curved as shown? Why not just have a rectangular hollowed-out box that positions the lens in the proper place?
Alan


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## Whimsy (Oct 14, 2011)

@Alan S

Optically, it changes nothing. In fact a lot of diy pinhole cameras are simple boxes to avoid cutting complex shapes. Its more of a design preference. Since the image is projected in a cone the leading corners can be removed making it slightly less boxy.

Here are 3 examples of the type of camera I am trying to do. If posting others images are frowned on I will remove.

http://www.fotomancamera.com/product_list.asp?id=335









a similar diy version http://blog.makezine.com/archive/2006/12/darth-handy-homemade-came.html










and a diy version from a wooden flower pot. http://on-your-kitchen-worktop.blogspot.com/search/label/4x5


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## jeth (Aug 18, 2010)

You could make a router jig, similar to a planing sled but with curved sides so that the router travels in an arc.

That would work for the outside but might be tricky for the inside. The inside you could hog out the better part of the waste with the router or drill press and finish with a chisel/files.


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