big camera

I just got back home after visiting a friend who teaches art at a local high school and also has photography classes as well. While touring their well equipped darkroom and finishing area,he showed me a large plywood box about 24" square and said he'd inherited it when he took over the classes several years ago.After a little examination we discovered it was a pinhole camera,pretty well constructed and not worn looking at all.He asked and I couldn't tell him what size the pinhole should be for such a large camera.
We would appreciate any and all help we could receive to get this big old beast operating.
Thanks in advance,
Don

Sounds like great fun and just in time for WPPD!

If you can measure the distance from where the pinhole will be to the film plane, that is the most critical dimension. Then if you can estimate the size of film or probably photo paper that will fit, that would help too! Sounds like it might hold a piece of 16x20 inch paper, which could be a lot of fun.

You can go to a site like Mr. Pinhole and get most of what you need, but we might be able to do a little better if we know for example what kind of film or paper you'll use!

Hi Ned!
Thanks for your kind words(about the reflective enlarger)and offer of help with this pinhole camera.Most likely we'll be using Ilford multigrade paper,pearl or glossy( which ever we've the most of at the time).
I'll check out the "Mr.Pinhole" site soon,thanks again....

Hi Don,
With a focal length (= distance from pinhole to negative) of 24 inch I would use a pinhole size between 0.8 to 1,0 mm (= 0.032 to 0.04 inch), but not larger than 1.1 mm (= 0.043 inch).

If 24 inch are the outside measurements, it is quite well possible the focal length is shorter. If it is actually like 20 inch inside of the box, I would use a pinhole of 0.7 to 0.9 mm, but not larger than 1.0 mm.

To make a pinhole, just cut out a square from a soda can or use simple tin foil. For tips and guidance, see also: http://www.pinholeday.org/support/ or check some of the posts on my blog http://thetoadmen.blogspot.nl. There is also a Pinhole Photography & Camera group on Linkedin.

If you use photo paper as a negative, you can raid it as ISO 3 for starters. If you use a Windows computer, you could download a free program called Pinhole Designer to do the calculations for you (pinhole sizes, angle of view, exposure times). I tend to make my pinholes a bit smaller, than this program calculates, to get a bit sharper image. but if you follow its calculations, you'll be fine.

I made a 20x24 inch paper negative with a big pinhole camera made out of a cardboard box, similar to yours, for the previous MSA (cheap camera challenge) thread. To see how I did this, check:
http://www.apug.org/forums/viewpost.php?p=1608880
and
http://www.apug.org/forums/viewpost.php?p=1614832
and
http://www.apug.org/forums/viewpost.php?p=1617313
and the results:
http://www.apug.org/forums/viewpost.php?p=1617495



Above all: experiment and have fun! That's what pinhole photography is all about.

Bert from Holland
http://thetoadmen.blogspot.nl

Hi Don,

I want to add something to what Bert wrote, which is all great advice!

Pinhole photography does not need perfection and in fact imperfect pinholes and other details like the photo paper not being perfectly flat can add to the charm and uniqueness of the results. Maybe even the occasional light leak or flare!

I often make my pinholes like Bert is describing, with a general range of size in mind, and then just look at it under a magnifying glass next to a ruler. If it's close and does not have any obvious big burrs around the rim, it's fine! It will make a picture. My favorite coffee can camera has a pinhole that I never measured. I'm sure it is not precisely what a careful calculation would come up with, but it's still my favorite.

I'm going to write another post soon about this, because I've got a feeling that some people might think making a pinhole camera is more complicated or intricate than it really is. Some of us like to talk about the math, and about things that make small differences... and that could cause the impression that these things make more of a difference than they really do.

Ned

I totally agree with Ned!! Don't make it a too technical or mathematical exercise.
Pinholes don't have to be perfect, indeed. Imperfect pinholes may give beautiful images as well. Sometimes even better. Use the sizes I mentioned as a starting point, but also try a much larger and a much smaller pinhole to see what it does.
Sometimes I just use a sheet of tin foil, pinch a small hole with a needle and make a shot. I've even made landscape images with a pinhole camera handheld (no tripod) with an exposure time of 40 seconds.

It is good to understand (up to a point) the theory behind pinhole photography when you start with it, but take the opportunity to use it for your own creativity. Try even two pinholes next to each other, just to see what it will do. Smaller pinholes tend to be sharper, a bit larger pinhole may give a nice softness to the image.

When you make a test shot with a camera as big as yours, first try a smaller sheet of paper to test it. Like a 8x10" paper in the middle of the back of the camera. And if you can't find a larger size photo paper, just tape (use green Scotch tape) several smaller sheets next to each other. Also easier to develop as well

Thanks again guy's for the links and suggestions,I'm going to share them with my teacher friend and see if we can pursue resurrecting this old camera.
It may depend on whether the school will allow us to play with it (I suspect they won't care but he'll have to check it out).It would be great if he could liberate it while the school's on summer break.I would think showing the results to his students would be stimulating,we'll see how it goes......

Good luck Don - I am pretty sure you will teach the teacher.

Don and I have a common past, we are/were both Lisle Camera operators( there may have been a handful of us in North America doing complex photocomp in the 80's. What Don has forgotten about photography and film in particular is more than most can ever achieve with years of steady practice.
We are very lucky to have him join our ranks here on APUG and he is a resource extraordinare for all you younger workers, I visited him in Kansas back in the 80's and to see what he could do with photomontage well , simply outstanding.

Don I think you should look out for some big old film for that camera , lots of people here with knowledge on where to get it.


Bob

blindpig said:

Thanks again guy's for the links and suggestions,I'm going to share them with my teacher friend and see if we can pursue resurrecting this old camera.
It may depend on whether the school will allow us to play with it (I suspect they won't care but he'll have to check it out).It would be great if he could liberate it while the school's on summer break.I would think showing the results to his students would be stimulating,we'll see how it goes......

Click to expand...

WOW! Bob,
Thanks for the pat on the back,you and I do go back a long way and enjoyed then "cutting edge "photocompositing (really doesn't seem that long ago).Technical advances keep marching on and tools like Adobe Photoshop finally put the then highly specialized" photocomp" business in anyone's hands who'd take time to learn their process.
I would like to locate some large size continuous tone film,even outdated X-Ray (mammogram type as I understand it's only silver coated on one side) but trying to locate it on the cheap hasn't worked out so far LOL! Like you, later on carbon printing is on my bucket list as well as large pinhole stuff.....

I have purchased some different types of film lately, some very cheap and some very expensive, up to my old tricks and pushing the envelope with my laser device to see which film
gives me the results I want.

I will pass on any info I get later this year.

I have purchased some different types of film lately, some very cheap and some very expensive, up to my old tricks and pushing the envelope with my laser device to see which film
gives me the results I want.

I will pass on any info I get later this year.