Building a FrankenCamera.. Choosing a lens

[ibcrewin]

I have been practicing making some bellows because I saw a post on Makezine.com. So I've decided I want to make LF pinhole camera. Then I thought well how about a FrankenCamera! I have a lens from a Ansco viking I could use.

I have the feeling it will not work since the lens was probably designed for a fixed focal lenth. So my question is, can I use MF lens on bellows camera and use it for anything besides it's desinged focal length?

Ivan

 

[bmattock]

I have been practicing making some bellows because I saw a post on Makezine.com. So I've decided I want to make LF pinhole camera. Then I thought well how about a FrankenCamera! I have a lens from a Ansco viking I could use.

I have the feeling it will not work since the lens was probably designed for a fixed focal lenth. So my question is, can I use MF lens on bellows camera and use it for anything besides it's desinged focal length?

Ivan

A bellows, as you know, is used to vary the distance between a lens and the recording media, thus changing the focus.

You don't need a bellows for a pinhole camera, because it has an effective 'infinite' depth-of-field, so no 'focus' is possible. That's why pinhole cameras are always simple boxes (or other interesting devices, like soup cans, etc).

A camera lens, on the other hand, has a focus point. If you want to put it on a bellows and use it to focus, no problem. You just have to find out where it focuses to infinity and then make that the farthest position away from the film. Any closer, and you are focusing closer.

As to using a lens designed for medium format on a camera of another type, that depends upon the image circle cast by the lens in question. Most medium format lenses are going to cast a smaller circle than you need for large format. Some few of them might cast an image circle that would get you to 4x5, but no larger. And most would not. You could use them, but you'd get a circle of an image, with the corners of the film being unexposed.

 

[ibcrewin]

You don't need a bellows for a pinhole camera, because it has an effective 'infinite' depth-of-field, so no 'focus' is possible. That's why pinhole cameras are always simple boxes (or other interesting devices, like soup cans, etc).

But wait.. Aren't there optimal pinhole sizes for various focal lengths? Maybe it only makes a marginal difference?

 

[Whisper]

What lens is in the shutter?
A 105mm just might sneak to the edges of a 4X5 film.

 

[wpb]

A bellows on a pinhole camera will allow you to change the focal length. There are "optimal" pinhole sizes but it is all really relative to your expectations.

 

[venchka]

Hey, wait a minute

Hey, wait a minute

I already bought the FrankenKamera 2 weeks ago and returned it last Monday.

Said FrankenCamera was a Kodak 4x5 Master View Camera. The "lens" provided was a Prinz 150mm f:4.5 barrel lens with threads at the rear of the barrel. It bore a striking resemblance to a friend's Spiratone Macrobel lens originally sold as a macro lens for use on 35mm camera bellows. The shutter was an oldish Prontor Press dial set model. The thread diameter on the lens was smaller than the thread diameter of the shutter. No worries. A previous owner had stuck the lens in the shutter with some type of sticky goo resembling plumber's putty.

If that doesn't qualify as the FrankenKamera, I don't know what does. 😀

 

[MartinP]

quote from Bill "You just have to find out where it focuses to infinity and then make that the farthest position away from the film. Any closer, and you are focusing closer."

If you put the lens any closer to the film-plane than the infinity focus position, the nothing will be in focus. As the subject gets closer to the camera, the lens has to be further from the film-plane to stay in focus. I am sure you know this, but the typo won't help the original poster 😉

Nice project idea btw. The tricky bit is a practical home-made way of holding, and reloading the film, unless you use commercial film-holders.

 

[bmattock]

quote from Bill "You just have to find out where it focuses to infinity and then make that the farthest position away from the film. Any closer, and you are focusing closer."

If you put the lens any closer to the film-plane than the infinity focus position, the nothing will be in focus. As the subject gets closer to the camera, the lens has to be further from the film-plane to stay in focus. I am sure you know this, but the typo won't help the original poster 😉

Nice project idea btw. The tricky bit is a practical home-made way of holding, and reloading the film, unless you use commercial film-holders.

Sorry, you are absolutely right. The infinity mark is when the lens is CLOSEST to the film plane. MY BAD!!!