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View Full Version : a DIY ground glass



LotusEsp
14-Jul-2016, 13:09
I was disappointed with the stock GG on my Shen Hao, and given that I've had focusing problems, adding a fresnel between it and the lens wasnt appealing.
So I looked into creating my own GG in the hope that it's brighter than the stock.

I thought I'd test the method with a bit of old glass from a picture frame. that was probably about $1. Not the most optically perfect bit of glass but good enough to test out the process with.

I went to a woodworking store in Toronto and picked up some lapping grit. I got some 400 and 600 grade. Both were about $6 (canadian) for 2oz

I picked up a cheap glass cutter for under $10 and cut out a 4x5 bit from the pane with a template from the stock GG.

I used a dremel to grind down the edges and clipped corners (although I could have skipped the corner part)

After I got the shape right I put a small amount of grit on the larger bit of glass (left over after I cut my 4x5 piece out) and added a bit of water.
I put the new gg on top and started to gently and lightly move the glass around over the grit. I put a couple of shows on netflix and then after about 1.5 hours I had a beautifully frosted bit of glass

I couldn't believe how simple it was - more importantly, how much brighter it is than my stock GG. I didnt even bother with the 600 grit. I was happy enough with the look after 400

Randy Moe
14-Jul-2016, 15:56
I enjoy making them the same way. No Dremel.

Made 5 I think. 2 are 11 X 14.

DIY is great!

el french
15-Jul-2016, 22:38
Silicon carbide sandpaper works well for rounding the edges of glass.

Peter De Smidt
15-Jul-2016, 22:52
A Norton water stone (for woodworking tools) also works well. I used a 1000 grit one recently to make a glass.

LotusEsp
16-Jul-2016, 03:39
what would be the reason to go for a finer grit?

I only used the 400 grit but saw others went to 600 or even 800

would this impact on the brightness of the screen or is it just going to affect the grain size?

Ron (Netherlands)
17-Jul-2016, 10:47
impact on the grainsize. Coarser grit makes a brighter screen, finer grit makes it easier to focus.......

nede
17-Jul-2016, 15:38
I did a 8x10 GG with 600 grit
not brighter than my original chamonix (same luminosity), but I don't need a lupe anymore as it's very easy to focus
only bad effect is a loss of contrast (really need my darkcloth)