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John Berry ( Roadkill )
29-Apr-2005, 22:22
I took the sugestion, and ground my own glass for my 8X10. I have to say it came out pretty good. I just knew that it was going to break when I was down to a spot about the size of a dime. Glass: $2.20 Wet-dry sandpaper $.99 I already had valve grinding compound. Time: 45 minutes Having the glass ready when that Dorff got here in the mail: Priceless

Steven Barall
29-Apr-2005, 23:35
There are also a few different types of glass out there. I am familiar with this because I am in the glass business and also the picture framing business. Try Waterwhite glass which is a low iron glass making it much more clear and color free that cheap hardware store glass. I have never tried to make a ground glass out of the stuff but it might be interesting. I assume that the ground glass that might come with any camera is this type.
The top of the line glass is Waterwhite Antireflective otherwise known as Den Glass. It transmits almost %100 of the light it encounters. It's low iron and has a dichroic coating just like your lenses. Just don't grind off the coating. I can't recall if it's coated on one side or both.
Just for your framing information, the anti-glare coated glass is amazing stuff. We have a very colorful watercolor framed with a piece of cheap glass covering the left side and the good stuff on the right. The good stuff is almost invisible. People are shocked when they see it compared like that. Almost everyone spends the extra money.

Dave Moeller
30-Apr-2005, 05:33
I don't think I'd spend the money for coated glass for a ground glass regardless of whether or not the coating would stand up to the handling when the glass was being ground. In order to see the image well enough you'e going to be under the dark cloth anyhow...the coating on the glass should be pretty redundant with no light coming at it from the back side of the camera.

I got my hands on a couple of sheets of Starphire Ultra-clear glass for my contact printing frames. (Since I'm using it for UV-sensitive processes, I only gained betwee 1/3rd - 2/3rds of a stop...but it's faster than cheap window glass.) I may try to make the spare sheet into a ground glass to see how well that works.

Dave Moeller
30-Apr-2005, 05:35
I should have mentioned: I'd assumed that the suggestion for coated glass was meant to put the coating on the photographer side of the glass. Grinding the coating side would obviously remove the coating...it's actually removing some of the glass.

Also, any window glass or aquarium glass supplier can get Starphire glass for you.

Randy_5067
30-Apr-2005, 07:49
And, glass is not all clear. Go to a glass shop, have them take a piece of ultra-clear and a piece of standard glass, and you will see that standard glass is "green". Your windows in your home probably have that green tint to them, it is just that you won't notice or see it without something for comparison. All the storefront glass you see is green, not clear. Spend a couple extra bucks per piece and get the ultra clear at a glass shop, not from one of the home hardware shops.

Mark Sawyer
30-Apr-2005, 11:42
I've seen things framed with den glass, and didn't like the effect. I had to move around to find the right viewpoint so the color of the coating wouldn't show.

Has anyone tried grinding their glass on a lapidary slab polisher? These are made for grinding/polishing large flat surfaces of rock, almost identical to glass. Could be the perfect tool...

Eric Biggerstaff
30-Apr-2005, 20:20
John,

I am happy the glass came out OK for you. I kind of like knowing that I can make an extra ground glass any time I may need one. Those that I have made have worked great and in reading this email string I might try some different types of glass.

I use the grinding powders that I mentioned in earlier emails and like you experienced, I found making my own was VERY cheap. The more you practice the better the results will get, heck for a $10.00 investment you will be a pro.

Have a great one!

www.ericbiggerstaff.com

John Berry ( Roadkill )
1-May-2005, 02:37
I always do wet grinding as it keeps the grit from balling up under the sandpaper. Looking at the post I might try another on with some premo glass. Thanks everybody for the info.

Curt
2-May-2005, 00:47
Hello, can anyone tell me what the thickness of the Ultra clear glass that was ground for a 8 x 10 ground glass was? I read that the OE ground glass was thinner and the glass blanks that are in standard size is a mm size common to Europe. This accounts for the many breaks that occure, the OE glass is thin. Thanks, Curt

John Berry ( Roadkill )
3-May-2005, 10:34
It is my understanding that most ground glass is 2mm thick and the one I made was 1/8. That equals 3.18mm

Calamity Jane
3-May-2005, 15:40
I ground my own glass for my first camera. It's good experience.

After I bought a piece of SatinSnow, I don't even bother anymore - build or buy a camera, order SatinSnow for it. It's just standard equipment now.

Calamity Jane
3-May-2005, 17:23
I used fine valve grinding compound. Under the loupe, it looks pretty rough.

Whatever process is used to produce SatinSnow leaves no noticable grain or pitting.

Using a MUCH finer grinding compound would probably make a difference, probably a softer backing would help to.