Camera Conversion


TPF Noob!
Mar 10, 2012
Reaction score
Tallinn, Estonia
Can others edit my Photos
Photos OK to edit
Hey everyone!

Recently, I managed to drop my GoPro camera off the roof of a car. Basically, the optics got smashed, but all the electrical stuff still works.
So, I came up with an idea to build a new housing, that would fit an M42 lens. The problem is, that the films on original M42 cameras were a lot bigger than the GoPro's sensor. Can anyone tell me, what to do in order to somehow get more of the light to the sensor?

Kaspar Kalmer
It's not getting more light on the sensor that you need to worry about, it's the focal length of the lenses in question. The gopro has something like a 5mm focal length, good luck finding an M42 replacement for that.
OK then.
But is there maybe some other way to use GoPro's sensor with interchangeable lenses?

Kaspar Kalmer
What matters is the image circle the lens projects, and the flange to image senror distance. Most DSLR cameras have a reduced size image sensor, and the camera makers make lenses that project a reduced image circle to accommodate the image sensor size.

How will you handle focusing, and the lens aperture control that interchangable lenses have?
The flange to sensor distance shouldn't be a problem, but I guess the image circle that most lenses create is too wide/big for GoPro's sensor and that's exactly, what I'm worried about. Is there any way to make it smaller?

And I'll probably just set focus and aperture manually, shouldn't be a problem.

Kaspar Kalmer
Having too large an image circle isn't usually, in itself, a problem. You can mask off the unused parts of the IC to reduce the amount of stray light in the sensor box. The problems are usually more to do with lens resolution (the smaller the IC, the easier it is to design lenses with high resolution), angle of view and the accuracy and parallelism required because of the shallow depth of focus (not depth of field) of short lenses.
So, my question now is, how can I get the GoPro's sensor to work well with some kind of lenses (preferably M42)?
Basically, how can I make the image circle smaller? Adding a lens between the lens mount and sensor probably?

Kaspar Kalmer
Why do you want the image circle to be smaller? Hasn't this question already been answered?
Well, a big image circle and a small sensor put together would probably give me an angle of view of maybe some 10 degrees which is exactly what I don't want.
And no, there's no answer on how to make the image circle smaller.

Most reactions