Pinhole body cap exposure

[LifeIn35mm]

So when I started my photo class back in January our first project was to take photos with pinhole cameras and photo paper. Now I would like to get a pinhole body cap for my Nikon F3 (and maybe my K1000) but I was wondering if this is a good idea or not. I like the looks of pinhole but I am not the best at exposing it - when we where using the oatmeal box pinhole cameras I underexposed all my photos. I am not sure of any techniques on how to expose the 35mm film. Does anyone have any suggestions?

 

[DWThomas]

The "focal length" (pinhole to film distance) divided by the pinhole diameter gives an f-stop. Then you have to figure out an exposure time to work with whatever film and f-stop you have. For very long exposures, the time generally has to be further increased because of reciprocity failure of the film for long exposures.

There are websites and calculators to deal with some of this, and there should be some previous threads in this forum.

I will say that from what I've seen, the smaller formats tend to be less sharp than the larger ones like 4x5 and 8x10, but the desirability of using them depends on what you want results wise.

 

[summicron1]

calculate your exposure, then double it ... I've found it's a lot harder to over-expose in pinhole than you would imagine, but fairly easy to under-expose.

Keep in mind that the smaller the format for pinhole, the less definition to your image.

Really, if ur looking for certainty with pinhole, ur looking the wrong place. Pinhole is all about experimentation and learning and constantly being surprised.

 

[Ric Johnson]

Both my Mamiya & Nikon cameras use a body cap as a "pinhole". As easy as pie, but remember really really small pinholes. Then just shoot a roll of film. Take two exposures: first as double the time, second as triple the time. Then take notes so you can create your own chart. I need to double what my meter tells me on a normal and/or bright sunny days, triple the time in shade or cloudy days, four times as much in room light.

 

[DWThomas]

(Was a little busy earlier) A little more ...

There is (there was a url link here which no longer exists) discussing pinhole size. The size is dependent on the film format size, so it needs to be appropriate for the particular pinhole to film plane distance ("focal length" but not really!)

And TheToadMen started a thread with (there was a url link here which no longer exists) to pinhole related info, more toward the inspiration end.

The Worldwide Pinhole Photography Day folks have a page of resource information.

If you run Windoze, there is Pinhole Designer which can help optimize or analyze designs and also provide some exposure tools. It even generates reciprocity compensated tables for some films, but has not been updated for a long time so some of today's films are not covered.

There is Mr Pinhole with a web-based calculator. His predictions for coverage angles have seemed pessimistic, but I've not found what criteria he uses.

Fuji Acros has a good reputation for low reciprocity failure which makes it nice for pinhole work.

I say read up, wade in and experiment, that's what I do!

Further edit ... The pinhole itself needs to be in the thinnest material you can manage, so it would be typical to drill a large hole in a body cap and attach a thin pinhole plate over the hole in the thicker cap material.

 

[John Koehrer]

I had a tendency to use/misuse(?) the 35m pinhole almost as a lensed camera, it took a little while to overcome that habit.
Get closer dammit!