Quote Originally Posted by Steve Smith View Post
That would work. One Dioptre is a common size for supplementary close up lenses (it looks like that is what you are using already) the most common being the Canon +1 lens with a 58mm thread.

They seem to be available in 1, 2 and 4 Dioptres but not 3.

The adding of Dioptres method technically only works for lenses very close together but I think all of yours will be close enough for it to be a good approximation.

Something I learned here was that if you put a positive and negative lens together, you can create a degree of zoom by moving them apart.

Ah, the close up lense I have are +1, +2, +4 and +10, could those be the Dioptre values? I wanted to keep the lenses together for ease of focus, however I could look at having a front element and then move the back elements for focus rather than the whole assembly.

With regards to stopping the lens down, I had a Kodak autographic brownie which had the aperture iris in front of the lens rather than behind, I might look into this option as it would allow for the DIY camera to be set up slightly easier than having stops in the middle of the lens.