BS: Pinhole Cameras

Subject: RE: BS: Pinhole Cameras
From: Ernest
Date: 18 Apr 05 - 02:16 PM

Lily where are you? My girlfriend told me this morning there is an exhibition about pinhole photography in Montreal right now (includes a big one you can wealk in....)
Regards
Ernest

Subject: RE: BS: Pinhole Cameras
From: Bardford
Date: 18 Apr 05 - 02:03 PM

We turned a teacher friend's classoom into a camera obscura by blacking out the windows (I think we borrowed some big black garbage bags from the custodian)and taping white paper to the opposite wall. Or perhaps we used a portable board on wheels to experiment with the lens/filmplane distance. It was a while ago.

We used 'lenses' of various sizes - just circular cutouts in black paper, I think the dime-sized aperature worked best. We had a nice inverted view of the traffic on the highway outside the room.

I've also used 4x5 inch sheet film holders sheet film holders
in a wooden camera built to fit . Polaroid film holders will give you instant results.

There is a product called Liquid Light Liquid Light that you can coat onto various surfaces to make them light-sensitive. I've known people who make pinhole cameras from empty eggs using this stuff.

As far as exposure times - I used the Mississippi method - keep the shutter open for 3 or 10 or 20 or 60 Mississippi's, depending on your apeature and film speed.

Subject: RE: BS: Pinhole Cameras
From: JohnInKansas
Date: 18 Apr 05 - 01:10 PM

The pinhole effect has been known for quite a long time. The "camera obscura" name isn't generally used unless there's a lens (or mirror) involved; although one probably shouldn't be too fussy about it.

If the classroom has a small closet - or you can come up with a "wardrobe box" or something similar in size, creating a "sit in the camera" demonstrator could be a fun part of the lesson, especially for small students. Putting one kid in the "camera" and asking him/her to identify things placed outside by the others perhaps?

As mentioned, "blueprint" paper or the "whiteprint" paper commonly used to reproduce drawings can be used. It is relatively insensitive to low ambient light so that you can handle it without keeping it in total darkness if exposure is kept short and lighting reasonably dim.

Long exposures probably would be needed, but once exposed putting it in a "can" with a bit of ammonia should "develop" the image. You can probably just "wipe it" with a very slightly dampened ammonia swab for quicky use.

With "blueprint" paper the unexposed areas turn white and exposed and developed areas blue, making a negative.

With "whiteprint" paper the exposed areas turn white and the unexposed parts remain the original color (pale yellow, usually). With bright light or long enough time for exposure, you can look at the "exposure" in subdued light to "see if it's done." Exposure to ammonia or ammonia fumes turns the "yellow" to a permanent blue. You should be able to see the picture (in yellow) before developing it, but it will fade fairly quickly if left in the light before being developed.

There will be virtually no "gray-scale" to the prints. It's either white or blue in the finished picture. It's more practical really for "shadow pictures" where a leaf or other object laid directly on the paper and exposed. The image can be "fixed" after the exposed part turns decently white. It could work quite well in a pinhole setup for pictures of line-art posters, perhaps; although "real scenes" will likely be pretty "muddy."

Of course ammonia is quite toxic, but that's true to some extent of nearly all photo chemicals - especially if used with youngsters.

Youngsters may be quite happy with "negatives," in which case precut b/w print paper may be a lot easier to handle in loading, unloading, and developing than most films.

Almost any film or print paper can be "reversed" during development to make direct positives. You "partially develop" and then "flash" with a controlled light exposure to make a "negative of the negative" using unexposed photo grains behind the ones that developed on the surface; and then complete the "development." This is a very touchy process and not recommended for the inexperienced. Extra credit maybe - when they get to Senior Chemistry.

John

Subject: RE: BS: Pinhole Cameras
From: GUEST,Allen
Date: 18 Apr 05 - 11:58 AM

Stilly, that's a camera obscura basicaly.

Subject: RE: BS: Pinhole Cameras
From: Micca
Date: 18 Apr 05 - 11:45 AM

Lily, when we did this at a school where I worked(I am a Science Technician) we found that the cleaner (and within a cerain range of small sizes)and more circular the hole the better and cleaner the image, we solved part of the problem by making a larger hole in the container and gaffer tapeing a piece of aluminium foil over it and made the hole in the foil using a needle, NOT a pin, as the profile of the point on the needle is better. a focusing screeen was also very useful we made one from a piece of tracing paper stretched on a frame and placed in the position the pahotographic paper would occupy. We also had a supply ( I dont know from where) of photographic paper that produced a positive image on developement so there was no need to make a negative first. it was fun and

Subject: RE: BS: Pinhole Cameras
From: Stilly River Sage
Date: 18 Apr 05 - 10:31 AM

I used them in elementary school. As an observation for those with interestingly placed closets: I used to take the phone (ages ago, when the phone was still on a long cord) and sit in a hall closet where I would be undisturbed when talking to friends. This long narrow closet had a door on either side of it, and the doors had keyholes. The door on the side that went into our library used to have a pinhole effect through the keyhole. I'd sit in the dark closet and look at an upside down image of the library windows on the wall opposite the door.

SRS

Subject: RE: BS: Pinhole Cameras
From: GUEST,Allen
Date: 18 Apr 05 - 09:52 AM

We made them for photography class in school out of coffee cans. Great fun and some crazy results.

Subject: RE: BS: Pinhole Cameras
From: The Fooles Troupe
Date: 18 Apr 05 - 09:05 AM

My post seems to have got lost - but you should find info on some of those "Science is Wonderful" web sites around.

Subject: RE: BS: Pinhole Cameras
From: EBarnacle
Date: 18 Apr 05 - 09:00 AM

If you go to the Museum of Modern Art in New York, you can see a series of photos shot from the start of rebuilding to the end. There are, I believe 4 different angles and the shutters were opened at the start and closed at completion. The way the process of building is shown as part of the completed object is absolutely fascinating. Go see it. Although I don't believe the work was done with a pinhole, the effects are similar.

Subject: RE: BS: Pinhole Cameras
From: Duane D.
Date: 18 Apr 05 - 08:49 AM

If you use the oatmeal cannister, you might consider the idea of two usable film planes. You could have one pinhole on one end and a second one on the side with removable covers depending on which one you are using. By using the pinhole on the end, you'll get a normal looking image, but by using the pihole on the side, you'll get special effects, tends to look like a wide angle effect. Many years ago a co-worker of mine was experimenting with pinhole cameras using the film for a blueprint machine. It required very long exposures, but the film was developed by running it through the blueprint machine. Have fun.

Subject: RE: BS: Pinhole Cameras
From: Keith A of Hertford
Date: 18 Apr 05 - 08:27 AM

No focal lengths to worry about, but the hole-film distance will effect the field of view.

Subject: RE: BS: Pinhole Cameras
From: Rapparee
Date: 18 Apr 05 - 07:54 AM

It's been a long, long time! I remember that the tinier the hole, the sharper the image (within limits, of course). Also that you have to set the focal length, but right now I can't remember how.

Subject: BS: Pinhole Cameras
From: LilyFestre
Date: 18 Apr 05 - 07:38 AM

Good Morning Everybody!

    I am wondering if any of you have ever made or used a pinhole camera? I am working on a project for school and I have decided to focus in on pinhole photography. I have found several resources online describing how to make a pinhole camera out of a variety of items (I am partial to the oatmeal canister), how to use the camera once it has been built and then, of course, how to develop the photos.

   As for my own experience, I made one as a child and rememeber having LOTS of fun with it. I believe it was made out of shoebox and the photos tended to have a dreamlike (foggy) quality to them.

   I'd love to hear from any of you who have built or used a pinhole camera and your thoughts on them!

Thanks!

ML