Film for pinhole camera

[Stillwater]

So after seeing the pinhole pictures posted by fstop23 earlier today, I'm hooked. I've been researching them all day, and am planning to make one tonight after I get off work. But I have a question about the films i could use in a pinhole camera, or what I could possibly use.. I shoot 35mm film, but I'm a poor college student and its getting expensive. I don't have the equipment to develop film myself, so what kind of film could I use that wouldn't require developing (if possible) or very little to none. Could I throw a polaroid in there? If so, how would I keep it from exposing when I removed it later?

 

[JamesD]

I don't have the equipment to develop film myself, so what kind of film could I use that wouldn't require developing (if possible) or very little to none. Could I throw a polaroid in there? If so, how would I keep it from exposing when I removed it later?

In general, you'd want to load and unload pinhole cameras in a dark room, preferably a darkroom. Failing that, a changing bag. Failing that, I dunno. I've been known to use a buttoned-up coat, with my arms in the sleeves, and the neck and bottom folded up. I do this in a dark closet.

As for film, there's no reason you shouldn't be able to use Polaroid. Personally, I prefer paper negatives.... easily an order of magnitude cheaper than film, and it develops in Dektol, substantially cheaper than most film developers (especially when you dilute 1+5 or 1+10 for the paper negatives, like I do). I develop my 4X5 paper negatives in trays which are cut-out bottoms of plastic milk jugs. And a bathroom works just fine... a little light leaking around the bottom of a door has never hurt my work, and actually helps me see what I'm doing when I don't have a safelight installed.

Note that you're likely to encounter some reciprocity failure (you may have difficulty getting an image in other than sunlight), so some experimentation will be necessary to find the optimal exposure by means of experimentation.

Good luck, and be sure to post some results!

 

[PaulBennett]

Could I throw a polaroid in there? If so, how would I keep it from exposing when I removed it later?

I'm not recommending you use one, but Polaroid has/had a special 4x5 adapter and file soas to take Polaroid test shots in a 4x5 view camera. The Polaroid film has a self-contained dark slide envelope and the adapter allows pullout-processing. IIRC it's model 545. Cost is prohibitive for your present conditions but you should be aware of it's existence.

I went to your listed site and didn't find any specs on that pinhole camera. Are details posted anywhere? The shots are interesting but a bit soft for me. Not knowing how the camera is made, I can't figure where the aberation comes from. Certainly not the lens material.

tks

 

[JamesD]

The only real specifications for a pinhole camera are pinhole diameter (aperture), distance from aperture to film plane ("focal length"), and dimensions of film plane. You can calculate f-stop the usual way, by dividing "focal length" by aperture diameter.

The images formed by pinhole cameras will essentially never be sharp. If you imagine a ray of light coming from anywhere in the scene, traveling through a single infinitesimal point, and continuing on, you can easily see that the ray of light will be a single line.

The pinhole is not infinitesimal, however (or else no light could get in). It has a specific diameter, and so there's an area of uncertainty as to specifically where the ray of light is coming from. The ray essentially takes the form of a cone, with the points at the position in the scene from whence the ray of light is originating, and sides defined by the edges of the pinhole.

There's an infinite number of rays, though, so there's an infinite number of cones of light. Consequently, the bases of the cones overlap on the film plane. The radius of that cone is basically the limit of resolution. IIRC, this is called the circle of confusion. The net result is a fuzzy image.

Smaller pinholes will refine the cone and, in theory, increase resolution. However, two factors come into play. The first is that smaller aperture means longer exposure. (Infinitely small aperture results in an actual linear ray and infinite resolution, but also means infinite exposure time). The second is diffraction. The edges of the aperture actually bend light rays, causing ray spread and a larger circle on the film plane, further reducing resolution.

Finding the optimal pinhole diameter is kinda tricky. You have to balance exposure time, ray separation, and diffraction--diffraction itself is dependent on the thickness of the aperture and (again, IIRC) a few other factors.

But that's part of the charm. Find the right dimensions, experiment, and get the medium to work for your purposes. Beating the medium into submission is great fun! :mrgreen:

Hope that all makes sense.

 

[Stillwater]

I'm definitely going to go for the polaroid as my film medium I've decided. But now I have to figure out to release the reagent after exposing the film.. Oh well one thing at a time right?

Well, I'll post pictures of the camera PaulBennett and probably the process of making the camera too, so hopefully it turns out alright.

 

[Greedoe]

Stillwater, did you try using Polaroid? Did it work?

 

[astroNikon]

In a film class here, when they get around to creating/making Pinhole cameras they use a light sensitive paper. I've never looked into it but that might be an option - disclaimer - I've never seen the results from this. It's a photography class and they go to 35mm film cameras and digital cameras throughout the class.

 

[Greedoe]

Astro Nikon, I'm doing this as a project for a couple of students (middle school) interested in photography. They are making pinhole cameras using Altoids tins. I'm hoping to get some of those new, little polaroids and puncture the solution caps and roll the solution across the film (in a dark room) with a dowel rod or a pencil. Wish me luck lol

 

[limr]

Astro Nikon, I'm doing this as a project for a couple of students (middle school) interested in photography. They are making pinhole cameras using Altoids tins. I'm hoping to get some of those new, little polaroids and puncture the solution caps and roll the solution across the film (in a dark room) with a dowel rod or a pencil. Wish me luck lol

Well, you won't be using a cigarette packet, but the concept is all still the same
Lomography - Pinhole Passion: Instant Pinhole Camera in a Cigarette Pack

The procedure | Instax without Instax | Flickr

Also fyi, they just came out with Instax Mini in black and white. I'm still waiting for them to make b&w in the Wide format.

Good luck!

 

[snowbear]

I remember making one for 126 film cartridge (remember Instamatics?) using a 35mm film box - talk about a fusion product.