Chamonix 45 as a pinhole camera

[bbarna]

hi,
I have a Chamonix 45n-1 camera and I'm considering to use it as a pinhole camera.
I need some advise on how large to make the aperture and how far to extend the bellows when shooting if I try to imitate a 55mm focal length lens.
Any advice are very welcome.
Thank you,
Barna

[Ari]

There are Skink pinholes on eBay, these are precisely drilled with stainless steel apertures. You could contact them for more info.

[Walter Calahan]

http://www.pinholeresource.com/shop/shop?page=shop.product_details&flypage=flypage.tpl&product_id=55&category_id=18

[Greg Lockrey]

http://www.lenoxlaser.com/index.php?dispatch=categories.view&category_id=17
There is a pinhole for just about any focal length you need.

[Jack Dahlgren]

For a 55mm focal length, extend the bellows 55mm from the focal plane.

The commercially made pinholes are pretty expensive. I've built my own using the following process.

Get a sheet of brass shim stock from a hobby shop.
Place it on a firm surface and using something with a rounded end and a hammer, make a small dimple in the center of it. This is just to thin the metal a bit more.
Using fine sandpaper, sand the back of the metal until the back of the dimple is flat with the rest of the metal.
Using a sharp needle, tap the needle in the center of the dimple until it goes through the metal.
Remove the needle and again using the sandpaper (400 grit would work well) sand the back of the metal to remove any burrs.
Finally using the needle in hand. Put it lightly into the hole and rotate it from both the front and rear sides to ensure a nice round hole.

Using black photo tape, tape this over the hole in any lensboard that fits your camera.
You can make a shutter with a flap of the same tape.

[Greg Lockrey]

For a 55mm focal length, extend the bellows 55mm from the focal plane.

The commercially made pinholes are pretty expensive. I've built my own using the following process.

Get a sheet of brass shim stock from a hobby shop.
Place it on a firm surface and using something with a rounded end and a hammer, make a small dimple in the center of it. This is just to thin the metal a bit more.
Using fine sandpaper, sand the back of the metal until the back of the dimple is flat with the rest of the metal.
Using a sharp needle, tap the needle in the center of the dimple until it goes through the metal.
Remove the needle and again using the sandpaper (400 grit would work well) sand the back of the metal to remove any burrs.
Finally using the needle in hand. Put it lightly into the hole and rotate it from both the front and rear sides to ensure a nice round hole.

Using black photo tape, tape this over the hole in any lensboard that fits your camera.
You can make a shutter with a flap of the same tape.

Now you see why they are so expensive.... ;) ;)

[Nathan Appel]

For a 55mm focal length, extend the bellows 55mm from the focal plane.

The commercially made pinholes are pretty expensive. I've built my own using the following process.

Get a sheet of brass shim stock from a hobby shop.
Place it on a firm surface and using something with a rounded end and a hammer, make a small dimple in the center of it. This is just to thin the metal a bit more.
Using fine sandpaper, sand the back of the metal until the back of the dimple is flat with the rest of the metal.
Using a sharp needle, tap the needle in the center of the dimple until it goes through the metal.
Remove the needle and again using the sandpaper (400 grit would work well) sand the back of the metal to remove any burrs.
Finally using the needle in hand. Put it lightly into the hole and rotate it from both the front and rear sides to ensure a nice round hole.

Using black photo tape, tape this over the hole in any lensboard that fits your camera.
You can make a shutter with a flap of the same tape.
that's how we made them in art school also!!! they work perfect that way.

[Jack Dahlgren]

Now you see why they are so expensive.... ;) ;)

With one piece of brass you can turn out a dozen different sizes in about half an hour.

[Greg Lockrey]

With one piece of brass you can turn out a dozen different sizes in about half an hour.

Those laser cut holes are so clean and precise for the focal length that images look like they where shot with a lens. My signature pic is a pinhole BTW.

[Jim Jones]

Any serious pinhole photographer should visit http://www.f295.org/. Another interesting site is http://home.online.no/~gjon/pinhole.htm. One engineer's look at pinhole photography is http://inside.mines.edu/~mmyoung/PHCamera.pdf (http://inside.mines.edu/~mmyoung/PHCamera.pdf)The standard reference is Pinhole Photography by Eric Renner.

The optimum size for the pinhole is more critical than many believe. It has been debated for over a hundred years. Perhaps the serious math in Lord Rayleigh's 1891 paper http://idea.uwosh.edu/nick/rayleigh.pdf has convinced some that it the best available information. Practical pinhole photography proves otherwise. For best on-axis resolution I use www.pinhole.cz/en/pinholedesigner/ with a user constant of 1.5. However, resolution and sharpness aren't the only significant criteria, as Verito users know. A slightly larger pinhole improves off-axis performance. Tilting the pinhole helps when raising the front on a view camera. The theory of pinhole photography should appeal to the engineer or scientist. The application verges on black magic.