Ground Glass Cleaning

[Santo Roman]

Is there a particular way i should clean my ground glass? I picked it up off ebay a few months ago and noticed that it might be a bit dirty. Is there any special cleaner I should use?

santo

[Alan Davenport]

Windex comes to mind.

[WOLF]

This may sound like a stupid follow up to this question for this subject but I have an older Seneca and the ground glass I have appears to be frosted? In other words it is NOT crystal clear like a sheet of glass. When I was wiping the camera down the other day - my finger tips came in contact with the edge of the frosted part - SHOULD this be cleaned to the point of being clear or is the frosted part supposed to be left alone?

[Dave Parker]

Cleaning ground glass is very simple, warm water and a grease cutting detergent with a scotch bright pad, is what I use on every single new screen I ship out, just wet the glass with warm water, couple of drops of the soap and then scrub with the scotch bright and rinse in hot water, this will remove finger dirt, and other air born contaminants that have penetrated the pours of the glass.

Wolf you can clean it with no problem, but it is suppose to be frosted on one side, that is the side of the glass, that faces the lens, to allow for focusing.

This cleaning technique works one all true ground glass, do not do it on an enhanced screen or a fresnel. Also, if you have a grid on your screen do not scrub as you run the risk of removing the lines, as most are screen printed on the glass.

Dave Parker
Satin Snow Ground Glass

[WOLF]

Dave, the side my finger tips came in contact with is on the outside of the camera? This is on an older Seneca 5x7 I just picked up, while getting it dusted off, it was the outside portion of the glass, I would think this "might" be the original piece since it was purchased from someone who found it in their grandfathers basement? So if I unmount it from the back then I should be able to wash it per your instructions? This is the last thing I have avoided in cleaning this up, the lens on this unit is in a BETAX shutter and the glass looks to be in VERY good shape. Thanks for all your input so far.

[Dave Parker]

Wolf,

In all of the cameras I have dealt with over many years, the frosted side was always mounted on the same side as the lens, this is where you focus your image, but again, just un-mount and carefully wash per the routine I posted, be very careful as older glass has a tendency to get brittle over time...but it should be fine as long as you don't bump or drop it, then mount again, holding it by the edges, drop into the recess and then lightly tighten the screws down, try to avoid to much pressure when screwing them down, they don't need to be tightened all the way down, just enough to compress the clips a bit and keep the screen from rattling.

Dave

[Peter K]

Dave,

theres is one reason to turn the groundglass with the smooth side to the lens. With "Autochrome" and other early color plates one had to be exposured through the glass. So the groundglass must be turned to avoid focusing problems.

Peter K

[Dave Parker]

Thanks Peter,

I have never shot "plates" just thousands of sheets of film over the last 20 years, as plates were not mentioned in his question, I presumed he was talking about shooting film.

But it is good to have the information.

Thanks again.

Dave

[WOLF]

Dave - hey just a late thanks with your help, when I get a chance I will go ahead and wash the glass as you described, the crazy thing is that I am wondering now if by chance I was actually wiping off the dust since it was stored for so long in that basement and I was being so paranoid on ruining the glass being new to this kind of equipment, if it is dust and comes out cleaner I can only imagine how much brighter the image will become.

Thanks again