New here

[maxernest]

Hello, I'm new in this forum and somewhat new in analogue photography. I have a few years of practice with my beloved olympus om10. I try to carry it everywhere I go. I had a few personal projects that started but never came to an end. Now I find myself attracted to the possibilities of double-exposure and all that this can bring. I decided to join this forum to ask a relatively physics-related question, hopefully someone can answer it. I couldn't find the "correct" subforum, so here it goes:

I want to to take a photo in which half of the final image is covered (black). I've been doing some reading and found out that, somehow counter-intuitively, if you cover half the lens with a black sheet, you don't hide what's behind it, but just make the image less bright. This is due to that even though there are some light rays covered, some of them still arrive to the lens through the non-convered part. Link for diagram and further explanation: http://www.physics.usyd.edu.au/super/physics_tut/activities/Waves_and_Optics/Half_a_Lens.pdf

My question is, how do you actually cover part of the image with a sheet in between what need to be covered and the camera? Is this dependent on the objective's focal length? I am currently using a 50mm objective.

Thanks,

M.

 

[Konical]

Good Morning, Maxernest,

It's probably not practical with the OM-10. With view cameras, what I think you're trying to accomplish can be done with partial dark slides inserted. It would be a lot easier to do this in the darkroom with half the print covered and uncovered as needed.

Konical

 

[Sirius Glass]

Welcome to APUG

 

[fotch]

Hello and welcome to APUG.

 

[mike c]

Welcome maxernest, I do not understand your question, I can see what they are doing on the link and if you are duplicating just hold a black card close and halfway up to the front of the camera lens.

 

[papagene]

Hello and welcome to APUG!