Plans for a 4x5 pinhole needed.

[Robert Kennedy]

I am thinking of making two cameras. One a pinhole. And one a modified pinhole that takes a holga lens and shutter on the front and takes 6cmx9cm plate holders.

Thing is, I nee to figure out how to build a back. The front and sides are the easy part after all. But to get a working 4x5 back system in place is a bit trickier.

Any help would be greatly apperciated. I figure a simple 4x5 pinhole owuld be my first attempt, with the Holgahole coming later.

 

[removed account4]

for the 4x5 you could check out how they do backs on the leonardo at the pinhole resource. it is pretty simply done - a cut-out in the back of the camera/box and lined with light-block and 2 sliding blocks to secure the film holder. i think the cameras made by the lensless camera company ( santa barbara camera company ?) are done the same way.

http://www.pinholeresource.com/agora/agora.cgi?cart_id=&xm=on&product=Cameras

good luck!

 

[jimgalli]

What about 3X4 Polaroid packfilm? I have at least one back half of a Polaroid CU-5 out in the garage. Nice packfilm back already there, all you have to do is cobble the pin hole on with some tape. Gives you about 4" on a 3X4 which is kind of normalish. I may have 2.

 

[Robert Kennedy]

I figured 4x5 since I already have a bunch of holders, film, a Polaroid holder.....

 

[Mongo]

If you don't need GG viewing, how about just holding the film holder in place with two big rubber bands?

If you do need a GG, you could build a simple frame that holds a GG at the same plane as the film holder (you might even be able to scavange a bad film holder to make this), and use the rubber band trick to hold that in place before swapping in the film holder.

 

[ElrodCod]

4 X 5 Pinhole Camera

Robert,
Check out the camera I'm building here. It might be just what you want. If you check again this evening there'll be some new pictures posted. PM me here or at f295 if you have any questions.

 

[127]

I've attatched my "plans" that I used to build the back for my 45 camera. They're a little rough, and clearly show signs of use, but they actually work pretty well.

There are two parts: the inner back(ib) top left, is basically a square with the 45 aperture cut in it.

The outer back (ob) has the shape of the holder cut in it, as a U shape, so the top of the holder pokes out the top.

They fit together,as shown at the bottom. This leaves a bevel all of the way round (6mm- the whole thing was constructed from 6mm mdf) where the sides of the camera fit in to form light tight corners. Youl need to cut a slot on each side of the inner back which the ridge at the top of the dark slide fits into.

I tried to build it square so I could fit it to the front in both landscape and portrait, but my tollerences weren't good enough. In retrospect I would reduce the width, as it serves no purpose.

The results are quite light tight but could probably be improved by the lining the area around the darkslide with velvet type material.

For focusing I simply cut a rectangle of cardboard, and taped some greaseproof paper to it - worked great. I intend to build something more substantial using a translucent plastic milk carton as the viewing screen (I've tested this and it works really well). I was able to focus with this simple arrangement to pretty decent accuracy.

Ian

 

[Robert Kennedy]

Thank you all for the plans and info. I'm probably going with the "Elrod Design" for sheer simplicity. Although knowing how to do a real 4x5 back could be useful for my Holga project.

 

[tpersin]

pinhole camera plans

here are some plans from popular woodworking that may help you.
i've built 2 cameras using these plans and it accomodates most 4x5 film holders, as well as a polaroid 545.

http://www.popularwoodworking.com/features/fea.asp?id=1048

Tom
--------
http://f295.tompersinger.com