Ground Glass Info
 

Hi everyone, I have done a lot of reading about peoples plans on how to make mini35s and it's a pretty simple idea from what I understand, the only problem is that this "ground glass" that everyone is trying to make.

I read that you can do it by sanding down a UV filter with sandpaper or you can use wax, but why can't you just buy a focusing screen and use it? If you can could you not just buy a cheap one like the one at the following link: http://www.bhphotovideo.com/bnh/cont...ughType=search

I know it's a stupid question and I'll probably get bashed but someone please enlighten me.

Thanks,
Cory Cone

Hi Cory!

The big reason not to use a focusing screen from a camera is because most of them have markings...and if you find one without markings (like the one posted), it still likely won't have a fine enough grain.

The first couple of ground glasses I made were from UV filters. Then I learned I could use 50mm glass from 99 cent picture frames just as well...and I saved a bunch of money.

The best results I've had were with microcrystalline wax: http://70.147.193.182/mwtest

...however it is a bit more tricky than glass grinding.


I still think the best solution, if you have the money & equipment, is a moving ground glass - You'd get as much light as possible and grain wouldn't be an issue. I've made some very low-tech attempts at this, but nothing near as good as what Les Dit, Dan D., Ori, and some of the others have done.

Hope this helps!

Is that a field lens sitting in front of your GG Frank? Or just a condenser? (the rounded rectangular glass piece)

the screen could work if you vibrated it.

Thanks for the info guys.

So the GG does not need to be perfect if you can vibrate it? Or does it need to be spun?

One more question, when I'm sanding the glass with 600 grit, I read somewhere to use oil, should I use any oil? If so what kind? If not do I just sand with straight sand paper?

Thanks