Help with ground glass

[russ_lowgren]

I have an Arca-Swiss monorail camera and the original ground glass

broke (a very nice one with architectural grid). I replaced it with

the glass and frensal lens of an old crown graphic I had. This works,

but focusing is difficult to be precise. Any help on a good 4x5

ground glass and a place to purchase one would be greatly appreciated.

[leonard_evens]

I got a screen from Bill Maxwell of Maxwell Precision Optics to replace the original gg in my Toho FC-45X. It cost slightly over $200 and was well worth the cost.

[ellis_vener_photography]

I would contact Arca-Swiss.

[brian_kennedy]

I'd try Badger Graphic. They list "Arca-Swiss Ground Glass for 4x5" on their site for $65 (see <A HREF="http://www.badgergraphic.com/search_product2.asp?x=1623">http://www.badgergraphic.com/search_product2.asp?x=1623</A>). At that price I wonder what you get, probably not the fresnel screen. In any event, it wouldn't hurt to call.

[wally_hess]

I have a related question. I have access to a sandblasting booth at work and wonder what size grit is best to use if I make my own ground glass?

Thanks

[robert_a._zeichner1]

Wally and others, sandblasting a piece of glass for use as a focusing screen is a bit like harpooning smelt! When you sandblast, you are pelting the glass with rocks and creating chinks that will be very visible and annoying. What I suggest is that you read and follow Dick Dokas' advice in the last issue of Photo Techniques. I've made two gg's using this method and it works great. Best gg's I've ever used. You can create any kind of ruling you desire using a fine mechanical pencil with a hard lead.

[tim_curry]

If you want to try making a ground glass yourself, here are a few suggestions. Get the 500 grit carborundum(sp?) grinding compound from a lapidary supply. Have the glass cut to size so you know it will fit properly in the back. Have a thicker and larger plate glass cut (3/16" or 1/4", 4mm or 6mm) for a flat grinding surface. The glass back itself should have some type of tape covering the viewing side to avoid scratches while working the piece (duct tape, masking tape).

 

Use a small amount of grinding compound and water on the thicker plate glass to make a slurry and carefully place the "gg" on this surface. Use small circular motions and light pressure from your plam to polish the surface. It won't take very long to do the work. Rinse, peel a corner of the tape and check your surface. Trial & error, a bit of time and almost no money are involved. Make a few once you have a system that works for you. Draw a grid on the ground side with a fine point marker or soft pencil to set the format and references you need.

[colin carron]

Stephen Shuart does a very reaonable line in ground glass. I am using a piece he supplied plus my old fresnel and it works fine.

 

www.stephenshuart.com

[martin_czermak]

Russ,

 

a friend of mine did following:

he orderd a clear, coplanar dressed glass at an optometrist. he putted on the viewers side and along all four small sides an acid-proof coating. the coating is a kind of bitumen-lacquer. after the coating was dry he swayed the gg thru the steam of hydrofluoric acid. the result was... i have no words for that. the best matting i have ever seen.

okay, this procedure has some handicaps too. you have no grid lines for architectural applications. but my friend applied the lines later with a small black marker. the main handicap is: you will need two or three gg until you have the result you want.

but when you have the result, you will have a gg with the smoothest matting on the market.