What did Hopf and Satin Snow do differently during ground glass production?

[williaty]

Yes, Sir, it is, however asking how two of our most successful entrepreneurs/inventors make their product is too much like an intellectual property short-cut. If you could improve upon their product, do you not suspect that they could or have already, possibly deciding not to do so for financial reasons?

I want to make it myself because I like making things for myself. That's a big part of the reason why I work in LF. I am not concerned with improving on *their* products. What I'm curious about is whether what I've come up with is in the same ballpark as what many on this forum have recommended as the best simple ground glasses ever offered. All of the other ground glasses I have to compared to are factory produced with integrated fresnels.

Satin Snow is long gone and Hopf hasn't replied to several attempts to contact him before I gave up and started experimenting with making them myself. It's not like I'm taking money out of some kid's mouth by trying to make my own screens.

I really don't get why you're so hostile and acting like I'm a bad person just because I want to make a couple of good screens for cameras.

[Bob Salomon]

I want to make it myself because I like making things for myself. That's a big part of the reason why I work in LF. I am not concerned with improving on *their* products. What I'm curious about is whether what I've come up with is in the same ballpark as what many on this forum have recommended as the best simple ground glasses ever offered. All of the other ground glasses I have to compared to are factory produced with integrated fresnels.

Satin Snow is long gone and Hopf hasn't replied to several attempts to contact him before I gave up and started experimenting with making them myself. It's not like I'm taking money out of some kid's mouth by trying to make my own screens.

I really don't get why you're so hostile and acting like I'm a bad person just because I want to make a couple of good screens for cameras.

There are no ground glass screens with an integrated fresnel. All glass screens either are sandwiched with a fresnel, for instance some Wista screens, or the fresnel is an add on extra.
Except for the parifin wax sandwich Boss Screen that didn’t need a fresnel the plastic screens like the Super Screen or the Beattie Screen were frosted acrylic on one side with a fresnel on the back side.
Most of these, including the two named, were made in a Rochester, NY by Fresnel Optics. In fact, Beattie was owned by them.

[jnantz]

Wasn't there someone on these boards that recently posted a thread about him making gg? And, at reasonable prices, too, IIRC. I'd suggest doing a search here, if you're not going to make it yourself.

hello alan
it was barry young
http://www.largeformatphotography.in...Camera-Company

I've used wax paper

me too !
and sheets of thin plexiglass that i used an orbital sander on ...

[Bob Salomon]

hello alan
it was barry young
http://www.largeformatphotography.in...Camera-Company



me too !
and sheets of thin plexiglass that i used an orbital sander on ...

The old trick was to use a thin layer of shellac on the grain side of a gg (not plastic). It really made a difference, but had to be removed and reapplied every year or so.

[williaty]

There are no ground glass screens with an integrated fresnel. All glass screens either are sandwiched with a fresnel, for instance some Wista screens, or the fresnel is an add on extra.
Except for the parifin wax sandwich Boss Screen that didn’t need a fresnel the plastic screens like the Super Screen or the Beattie Screen were frosted acrylic on one side with a fresnel on the back side.
Most of these, including the two named, were made in a Rochester, NY by Fresnel Optics. In fact, Beattie was owned by them.

In both my Wista and my Toyo, the ground glass is inseparable from the fresnel; they are single monolithic chunk of plastic. Counts as integrated in my book.

[Bob Salomon]

In both my Wista and my Toyo, the ground glass is inseparable from the fresnel; they are single monolithic chunk of plastic. Counts as integrated in my book.

Wista has several ground glass screens for 45.

[jnantz]

The old trick was to use a thin layer of shellac on the grain side of a gg (not plastic). It really made a difference, but had to be removed and reapplied every year or so.

i wonder what happens when you say shelac 3x ?
i gotta find me a haunted house and a beetle farm

[Peter De Smidt]

I've made a number of glass screens using aluminum oxide powder. It really isn't very hard. It just takes a bit of time.

[williaty]

I've made a number of glass screens using aluminum oxide powder. It really isn't very hard. It just takes a bit of time.

What abrasive size did you use? Did you see different results through trying different sizes or techniques?

As I said, I've made a perfectly functional ground glass. I'm trying to learn if I can make a better than perfectly functional one now.

[Robert Brazile]

OK. That's kind of what I was planning on. With the 600 grit silicon carbide (which is roughly 11um), I got a serviceable screen. However, I'm cursed by wondering if things could be better. Since the silicon carbide grinds via fracturing, I think I'm going to order some 25um, 15um, and 9um white aluminum oxide (which grinds by planing/cutting) and give that a whirl. The good thing is that small quantities of abrasive are cheap. It'll just take me a while to grind a bunch of screens. Hence asking around to see if I could avoid re-inventing the wheel.

That is what I did on my 11x14 ground glass and I'm satisfied with the results.

Robert