Cleaning Crown Graphic Glass

[cuypers1807]

Just inherited a Crown Graphic and the ground glass is really dirty. Can anyone suggest what I should clean it with. Thanks from a 4x5 newbie.

Joby

[Frank Petronio]

Windex and soft rags...

[David Karp]

Not to contradict Frank, but make sure that you don't use Windex on the Fresnel lens! Ammonia is not good for plastic.

You can also use lukewarm soapy water on the glass and the Fresnel. Don't press to hard on the ridged side of the Fresnel. Pat it dry gently on with a soft rag to dry.

Once I cleaned the dirt off of my Crown's glass and Fresnel, I was amazed at how good it was. As good or better than any Fresnel GG combination I have seen on a modern view camera.

[Frank Petronio]

busted!

[Liam:]

I don't think most Crown Graphic's have a Fresnel? As mine didn't...

[cuypers1807]

I am not sure that mine does. Thank you for the advice.
Joby

[Frank Petronio]

Most do, I know that much, I've owned half a dozen and all the post WW2 ones had em.

[David Karp]

The Fresnels were made by Kodak and called Ektalite. Apparently, they became available in 1951. http://graflex.org/graflex-products-list.html

[Ivan J. Eberle]

Yeah, and if your Crown originally came with but nowadays doesn't have a Fresnel (particularly with the Graflok back), you'd be wise to double check whether a replacement simple ground glass is in the proper plane. (IOW if it wasn't shimmed to compensate for the difference in thickness, you will have focusing errors.)

[Lynn Jones]

Please don't use any version of windex, there are chemicals that you don't want near a camera, diaphragm, or shutter.

If it is really dirty use rubbing alcohol, in the pharmacy it comes as 50% and be sure that some fool doesn't put some kind of hand cream in the stuff.

Don't make it sloppy wet, just nice and damp, you don't want to drip alcohol into the system. Most of us in the optics industry usually use Kleenex with NO inclusions in the tissues. At Ilex and Celestron we used "Service Pack Kleenex", the cheapest stuff around with no perfume or creams. Another trick we used in the past was to buy packs of 500 cheap cotton (cotton only, no synthetics, they will scratch) handkerchiefs, wash them repeatedly in a washing machine from 15 to 30 times to get rid of any chemicals. The result is a lovely soft lens cloth.

Facial tissues are alright for optics, the fibers are much softer than any lens coatings. If any fibers are left over, use a rubber ear syringe to blow off the fibers-, no don't blow with your mouth, you might spit on the lens and then you have to start all over again.

Lynn

[Ivan J. Eberle]

Isopropyl alcohol is the stuff I use at 97%-99% concentration-- but only for cleaning lenses. (Because it doesn't contain glycerin, as often does rubbing alcohol.)

Note that full-strength IPA or other alcohol can dissolve certain vintage plastics. (e.g. DuPont Fabrikoid, a naugahyde-like camera covering from the 1920's-50's.)

I'd suggest that either a ground glass or Ektalite ought to clean up with a couple of drops of dish detergent and alcohol in a little bit of water. Nothing especially critical about the GG as it's not part or the optical path for picture-taking, as is the lens. (Don't soak an Ektalite, though-- just dip a corner of a t-shirt or other clean cloth in it, and apply with the cloth-- otherwise you might trap H20 between the GG and the fresnel.)

[Lynn Jones]

Right you are, Ivan.

Lynn

[Roger Vadim]

I was washing the ground glass and Fresnel like my dishes in warm to hot water with a little amount of soap/ dishes cleaner. Worked perfect and was one of the best advises I read here!

Start simple first, before using anything chemical.

good luck.
reme