"Super Bright" Ground Glass

[Eric James]

I have invited Mr. Mido to bring some samples of his work to the View Camera conference and show them around before he gets into any type of agreement with anyone. If he can do this with any standard gg he may want to have his own business doing this for people or there will be other companies for him to talk to at the conference.

This may be an important contribution to large format and I hope he will be cautious and explore all of his options.

Mr. Mido should also keep the process secret until he applies for a patent to protect himself from the process being done by anyone else. This patent process can take a while but I think, and I am not a patent attorney, that once he applies he has some protection already.

steve simmons

All good points! But be careful at any trade show Mr. Mido. If the substance, rather than the process, is patentable, anyone with access to a mass spectrometer could fly a miniscule sample and beat you to the punch.

[sanking]

What I don't understand is why the Crown/Speed Graphic ground glass would respond much better to the treatment than a Satin Snow ground glass. According to Mr. Mido, the treated Crown glass is 1 stop better than the treated Satin Snow glass, and treating the Satin Snow glass only improves brightness by 2/3 stop.

2/3 stop brightness improvement is nothing to laugh at, but I'm curious as to what the nature of the process is that would lead to the improvement.

First of all, the real issue is not whether or not you can make the ground glass brighter with some type of application, but whether brighter is also better. You can make almost any ground glass brighter by spraying a thin layer of polyurethane varnish on the ground side. However, depending on how finely the glass was ground this might result in a ground glass with a very hot spot in the center.

The improvement in brightness may be a product of how fine the glass was ground in the first place. If you were to spray polyurethane on very coase, medium and very fine ground glass the improvement in brightness would be greatest with the coarse, least with the fine.

Sandy King

[Richard Fenner]

I think the most pertinent question is, will this actually come to anything? People seem to have forgotten the last appearance on this forum by Shin-ichi Kumanomido (http://www.largeformatphotography.in...ad.php?t=19771 - second page for his posts) in which we got excited about the prospect of Mido holders being reborn. We indicated a willingness to part with large amounts of cash for the holders, but never heard from him again.

[Bob Salomon]

" However, depending on how finely the glass was ground this might result in a ground glass with a very hot spot in the center."

There are even more important question.

How well will the sharply focused image jump into focus?
How easy will it be to focus with a wide angle or an extreme wide angle lens and be able to see the sharply focused point snap into focus?
If it is very easy to focus with an extreme wide how well does the image snap into focus with long lenses?
Is there an effective range of focal lengths that this process works with or does it work equally well regardless of focal length?

Some grain in the ground glass is necessary to be able to see the image snap to focus. A plain piece of glass is very difficult to focus on even though it is brighter then a ground glass.

Lastly what happens to the image when your eye moves out of the optical axis? Does the image black out then?

You can't increase the volume of light striking the ground glass after passing through the lens. Is this narrowing the viewing angle by concentrating light so the eye must stay on the optical axis?

[Mido Holder]

On a question of the hot spot on a brighter screen: It is true that the even brightness of a g.g. and the hot spot is inversely related, especially with wide angle lenses. but if you look at the Wista flesnel/groung comb. It is a very good "compromise" .It is bright without the annoying hot spot, though it is a a bit stronger than other darker g.g. By comparing the S.B. g.g. with Wista combo side by side each fitted with 75mm Fujinon SW, the S.B. is as good as the Wista without paying $175 from a dealer. The Wista combo has no flesnel at the center (hot spot) about an inch in diameter that makes focusing easier. The Super Bright is an after treatment of the existing g.g. that is to be placed in front or behind the fresnel lens depending on the camera. Without the fresnel lens the S.B. g.g does exhibit a strong hot spot.

Shin

[Richard Fenner]

Shin!

It's very good to hear from you again. To slightly hijack a thread, did you make any progress on the idea of 11x14 Mido holders? You may recall there was considerable interest on this site.

Richard.

[Lightbender]

FWIW, ive used a drop of oil on a gg to brighten it up. By spreading it around the glass, then using a dry cloth to remove any excess, you will be left with a much brighter screen. However as said before, there forms a substantial hotspot if you cover the whole glass. It works better on a screen with a fresnel installed but is still very hard to focus a wide-angle lens. As an alternative, you can wipe the oil on only the center of the screen, but ive has problems keeping the 'center spot' uniformly round, and it distracts from composing the image. Focussing in the center of an oiled glass is wonderful, nice crisp clear images with good contrast.

One niec thing about the oil is that you can wash the glass with dish soap to remove it.

[runmtn2]

I have developed a new material and its coating process, "Super Bright", to brighten up the existing ground glass, up to almost 2 f stops. I will email to anyone interested in it actual photos the side by side ground glasses taped together, one S. B. treated and other not, onto which an image is projected. It clearly shows a dramatic difference in the brightness of the two ground glasses. I tried the S.B. coating on four different ground glasses from Graphic, Polaroid MP-3, Linhof, 5x7 B.J. Satin Snow, and Sinar. You will see the images of the all those treated and treated g.g.

p.s: Please send me your e-mail address, I will reply with attached photos.

Shin

[Scott --]

Did anyone get these pictures? Anyone care to email 'em to me? PM me, puh-leeeze...

[Donald Qualls]

Did anyone get these pictures? Anyone care to email 'em to me? PM me, puh-leeeze...

Scott, there was an attachment up the thread a bit, is that gone now?