Posted by Henry on February 13, 2001 at 06:31:37:
In Reply to: Re: Brighter Ground Glass-Century Graphic posted by Chuck Pere on February 13, 2001 at 04:28:01:: : : My Century has the factory ground glass. I
: : : understand that no fresnel was offered on the
: : : Century. Does anyone have any recommendations
: : : for a brighter ground glass for this camera?
: : : Chuck
: : Chuck, There was an Ektalite Screen (fresnel) for the 2x3. Used ones crop up now and again. They make the screen more uniformly bright but focussing is perhaps more difficult. There are two links from graflex.org containing very interesting discussions on various aspects of fresnels, pro and con. I bought an Ektalite Screen from Robert Pins in NJ (201-784-1444---get on his mailing list, he offers Graflex stuff), but wasn't happy with the results as it does not lie in the same plane of focus as the film. Two suggestions from the graflex.org links: coat the groundglass (lens) side of your present groundglass with Armorall Protectant OR Vaseline; wipe (polish) it off with a soft cloth. Enough residue remains on the groundglass surface to increase the light transmission factor (although you'll notice a "hot spot" which follows your eye around as you move your loupe over the glass). You can always remove the goop if you don't like the results. I tried it with Vaseline and it does work! And a heck of a lot cheaper (like "0") than a Beattie Intenscreen at $220!!
: Thanks for the information. My understanding is that no factory fresnel is available for the Century. If a 2x3 fresnel from another Graphic is installed it will shift the ground glass position unless it is smaller than the ground glass. This size would let it slip in front of the glass while still allowing the glass to fit against it's mounting lip. A fresnel may have been available for a 2x3 Speed or Crown but they must have had a back designed for it. Maybe the Centurys have two types of backs. One for fresnel and one without. But I can't find any references to this. The back I have would need a fresnel smaller than the glass.
Chuck, You're right, on all counts (of course, we can't ask "the
factory" anymore, so we have to improvise!). Two further thoughts:
1) have a glass supply house (or maybe an eyeglass place that does
its own in-house optics work) cut down the fresnel to fit on the
lens side of the back; you'll notice that there are four little
cut-outs visible in the back frame (two top, two bottom) which you
could maybe use in conjunction with two thin "keeper" strips (brass
shim stock from hobby shop?) to hold the fresnel. These would be
visible in the view, but would not impinge on a 6x7 format image.
OR (2), reverting to an idea from the graflex.org links, get a
fresnel flat magnifier from office supply place, cut to fit (paper
trimmer works fine), and mount as above. This works fine if you can
find a thin enough flat magnifier. I actually tried this latter
method, but eventually removed it because it made focussing a lot
harder with the 65mm Optar (which is already tricky enough).
Henry