Ground Glass Questions & Thoughts

[Raymond Bleesz]

Someone suggested on the LF forum, that one could make one's own ground glass--chemical grinding & or frosted spray. Another suggested a reputable company who does such work--Maxwell for example. Others? Another individual suggested using a computer screen, monitor screen.

Regarding this last option, a monitor screen cut to size. My question is: what pitfalls are there in using a monitor screen as a substitute for a ground glass? I have such on hand.

Another question: I have need of a ground glass screen for an unusual sized old antique camera---specifically a 6.5 x 8.5. My needs are not for a high end GG but something basic, either cut corners or sq, fresnel or not.

Since there are many options for purchase on EBay---low & high price wise, etc etc etc, would one have a suggestion regarding the purchase of an 8x10 GG and my cutting the GG down to the above size (I do have the equipment.)

Thank you for your input

[Ulophot]

I have no specific recommendations, but just a reminder that you will need to measure the exact distance to the film plane to make sure that the GG occupies the same lane when viewing.

[r_a_feldman]

It is not that hard to make your own ground glass. I did that for a Japanese half-plate field camera I have. There are a number of threads here with information on how to make your own.

[reddesert]

I made a ground glass for a 5x7. I used a 5x7" piece of picture frame glass, and some 600 grit silicon carbide I bought from a local rockhound/jewelers/tool shop, with another piece of glass as the "tool." A pound of 600 grit cost about $8 and is enough for several lifetimes; if you don't have a local shop you can buy it online. It's not hard and there are some videos on youtube about doing it. Getting a clean cut to size is harder than the actual grinding IMO.

[Raymond Bleesz]

Again---the first & last sentence

Regarding this last option, a monitor screen cut to size. My question is: what pitfalls are there in using a monitor screen as a substitute for a ground glass? I have such on hand.

Another question: I have need of a ground glass screen for an unusual sized old antique camera---specifically a 6.5 x 8.5. My needs are not for a high end GG but something basic, either cut corners or sq, fresnel or not.

Since there are many options for purchase on EBay---low & high price wise, etc etc etc, would one have a suggestion regarding the purchase of an 8x10 GG and my cutting the GG down to the above size (I do have the equipment.)

[Ron (Netherlands)]

Whole plate (or full plate) which you are referring to, is not an unusual plate size; however the glass ground screen on whole plate camera's may differ a bit in size. Best and cheapest option is to make one yourself. I've made quite some ground glasses: here's how I make them using silicon carbide as grinding powder with water: https://www.flickr.com/photos/zorki_...57660810886723

[Paul Ron]

you can cut any ground glass to size.

you can easily make your own by getting wet dry sanding paper from an auto supply used for auto body work. 600 grit is nice but i used an even finer paper so my image wouldnt look as granular.

[maltfalc]

an lcd monitor is made up of several layers sandwiched together. one of those layers is a thin sheet of plastic with an extremely fine grained frosted surface on one side and an anti-newton ring surface on the other. great for fine focusing and even illumination, at the cost of a bit of brightness. it just needs to be held in place between two sheets of glass, or a sheet of glass and a fresnel. it has a weird optical effect where it's more opaque and milky looking through one side than the other, so make sure you use it with the less milky side facing you.

[LabRat]

500 grit aluminum oxide polishing compound made a beautiful "satin snow" fine grain finish on cheap picture frame glass in less than a half hour of gentle circular movement grinding, and because of using another sheet of glass as a grinding tool, you end up with two GG's...

Less than a teaspoon of grinding compound wetted with a pump spray bottle with water + a trace of dish soap, and slide along the glasses until it needs another spritz of the solution, then wash and check...

You don't have to use the monitor glass as it is layered (so hard to get all layers exactly cut to size and thin layers), but frame glass is sturdy to work with and might be stock size already...

Lines are EZ with a sharp drawing pencil and a tri-square and precision rule...

Clean up sharp edges with some 320 Emery paper first to avoid cuts...

Use the aluminum oxide compound as this does not "dig" into and
not micro chip into the surfaces and produces a finer grain with less work while grinding (but slightly longer grinding)...

These come out so good at the first attempt, you will likely never buy a GG again, just make them forever...

Look up instructions posted on this site...

Fun, and good luck!!!

Steve K

[Rick A]

I made the GG for my old B&J Commercial View using a 5x7 picture frame glass and some valve grinding compound on my steel lapping plate. It took less than 30 minutes and I was quite pleased with the results. If you're having problems finding glass to fit just take the camera back to a glass shop or hardware that cuts glass and have a couple of pieces cut to size, it's inexpensive.