LF pinhole camera building

[andreios]

Hi,
I think this is my first post here, but I've been lurking around for some time soaking the know-how available here, but there are still some questions that I seek answers for.
I am regularly shooting BW with small format, using my OM gear and rangefinders, developing my film and occasional prints in the bathroom, but I still want something larger and slower. I decided to try large format to be able just to contact print the negatives (both from film and from paper negatives), and I intend to built my pinhole camera using the DIY method to get into LF processing before investing in a real LF camera.

Now to the questions - when building a camera - is it necessary to paint/cover the inside of the camera with a black non-reflective layer? (supposing the camera is built from heavy cardboard or plywood)

For the film pinhole I have ordered some filmholders from ebay - how can I ensure there are no light leaks in the opening for inserting the filmholder? Can I use some rubber sealing-thing I used recently for isolation of my windows?

How do you attach a DIY camera (a box, essentially) to a tripod?

Is there any method how to "compose" with a pinhole camera - supposing the "focal lenght" is not wide but more of "normal"?

Thank you in advance for all tips and answers.
regards
andreios

 

[Jim Jones]

It is certainly desirable to paint the interior black to prevent unwanted reflections. Also, some cardboard and thin plywood are not completely opaque. There are many ways of eliminating light leaks around the filmholders. One way is to design your camera like the backs of other large format cameras, using their light trap methods. T-nuts, available from most hardware stores, can simplify making tripod sockets. Tripod sockets on two sides of your camera permit it to be used in both portrait and landscape orientation. Composing is often done with lines drawn on the sides and top of the camera that show the angle of coverage. More elaborate viewfinders can be improvised.

Your questions may have already been answered in more depth on sites like http://www.f295.org/Pinholeforum/forum/Blah.pl? or Dead Link Removed.

 

[Christopher Walrath]

As far as composition, I would place the camera in a dark area (room, under a blanket, etc). Aim it at a brightly lit subject area and cover your back with a sheet of tracing paper or some such. Let your eyes adjust and you should just be able to make out some features in your subject area and through comparison between the projected image and your subject area what your coverage will be, albeit only roughly. PH is very much point and guess until you become familiar with your camera.

 

[jon.oman]

Here is a photo of a 4x5 pinhole camera next to an 8x10 inch camera. I built both, using plywood. You can see the 'sight' lines on the cameras to determine what the image will cover. For the tripod mount, you can see what I did on the 4x5 camera. It is a simple steel plate with a 1/4 inch hole tapped into it.

 

[jon.oman]

Here are a couple more images of the 4x5 camera:

Here is an image I made with it:

 

[andreios]

Jim, I've never held a "regular" LF camera in my hands, I think I'll have to find and study some pictures.. Thank you for pointing out those sites.
Chris, I think the point-and-guess might be a nice challenge - I imagine it like a "lottery" similar to "hip-shooting" I am trying from time to time with my old barnack rangefinder.
Thank you Jon for the pictures, they might prove very helpful! I've been thinking about something very similar. (And I hope that I'll also manage to take such a nice image as yours).

 

[Christopher Walrath]

Oh, I love the point and guess myself. Every once in a while I will break down and make myself a matchbox pinhole camera for 35mm film and just go out and have people gawk at me. I once had someone call over a police officer when I laid down this matchbox with two 35mm film cartridges black-taped to its sides and walked away. Not far away, but I was 'acting suspiciously'. Fortunately, the police officer was, of all things, a film photographer in high school so it did not take long to convince him I was not Osama binLaden.

 

[grahamp]

I have some construction details for a 5x4 pinhole made from a wooden cigar box here http://grahampatterson.home.comcast.net/~grahampatterson/grahamp/pinhole/index.html

I used a nut for the tripod socket, and various materials for light traps. Nothing as professional as jon.oman's, though.

Graham

 

[bobwysiwyg]

Here are a couple more images of the 4x5 camera:

Jon, nice job on the camera. I like the way you secured the holder, clever idea.

 

[andreios]

Nice job, Graham!
Few days ago I saw a similar box while visiting a friend and the idea of making a camera struck me as well. But to make it a bit easier I've been thinking about using a paper negative in it - it was just too beautiful to spoil it with making a hole for the film holder..
But thank you for the tip for tripod mount - seems quite easy.

 

[Joe VanCleave]

Regarding the inside of the camera, I'm fond of using black adhesive craft felt, found at craft stores in the US like Michael's or Hobby Lobby.

For making the camera back, be sure to include a shallow groove, along the side of the opening where the film holder goes, that mates up with the raised ridge along that side of the film holder; this provides the crucial light seal along that side of the holder. The other three sides of the film holder/film back mating surface should be protected by an overhanging ledge from the camera body, preventing direct light from hitting the mating surface. I like to cover the camera back mating surface with adhesive black craft foam, again available at craft stores -- with the caviate that it works well for pinhole lenses, less well for refractive lenses that require a very accurate focusing distance be maintained between lens and film holder; the craft foam is a bit squishy.

~Joe

 

[glarsson]

I've made several 4x5 pinhole cameras from foamcore and a glue gun using dimensions given here: http://pinhole.stanford.edu/foamcore.html. I used flat black spray paint inside the camera and covered all the joints with black electrical tape to prevent light leaks.

I tried using weatherstripping to make a light tight seal against the film holder but it didn't work for me, I still got light leaks. Now I just use black electrical tape to seal the edges where the film holder meets the camera. It works great and I can reuse the tape 6-8 times. Then again I'm doing IR pinhole with 20 minute exposures so a few extra seconds to seal up the film holder is no biggie.

To mount the camera to a tripod, I sunk a T-nut into a piece of scrap wood and attach the camera to the wood with big rubber bands that sometimes come wrapped around the mail. Changing the orientation of the camera is easy, portrait or landscape or even laying the tripod on its side for a low shot.

 

[andreios]

Thank you for another great ideas - particularly your tripod mount, glarsson, sounds like a great thing - to make a tripod base to use with several pinhole cameras might really do the trick!