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tom43
7-Feb-2018, 10:37
Dear all,

Im using my Intrepid Gen. 2 4x5 camera with several lenses, but especially with the darker once it could get quite tricky to focus. Are there any ground glasses out there, which are significantly brighter than the standard version? I know about the Maxwell screens, but these are quite costly. Is there a brighter screen out there in the range up to ca. $150-200, e.g. from Toyo, Linhof or one of the other known suppliers in this field? Many thanks in advance.

Luis-F-S
7-Feb-2018, 11:06
Steve Hopf borosilicate glass

LabRat
7-Feb-2018, 11:24
Another option you can try is to very lightly spray evenly, a VERY thin coat of silicone based spray over the frosted side (like Armor-All), where this will increase light transmission slightly by converting the GG to more of an aerial image (but at the cost of less GG grain to focus a loupe on, and less even illumination esp on the edges/corners), but brighter centrally... (But careful with acetone based silicone sprays if you have printed line grids on these, as this can melt/remove them...) If you don't like it, you can wash it off with dishwashing detergent and add a Fresnel...

Steve K

Paul Cunningham
7-Feb-2018, 11:24
A question for those who know. Aside from a Fresnel, what makes a ground glass brighter or not? Is it the color of the glass or the fineness of the matte? Or something else?

Whir-Click
7-Feb-2018, 11:54
Maxwell's screens are the best, hands down. Expensive but worth every penny. Steve Hopf's is my favorite plain ground glass so far, but is he still taking orders? I had no reply to an inquiry I made a few months ago.

LabRat
7-Feb-2018, 11:56
A question for those who know. Aside from a Fresnel, what makes a ground glass brighter or not? Is it the color of the glass or the fineness of the matte? Or something else?

The sides of the individual grains on the GG have more/less transmission due to the amount of fine grit blasted, but in the old days, some GG's were blasted, then slightly etched with hydrofluoric acid to smooth the grit slightly... (This is a lost art of balancing these points, and now hydrofluoric acid etching is largely banned everywhere...) Some original top GG screens on some RB Graflexes still have these...

One screen I had seen a long time ago was a blasted glass GG, that had a liquid (oil?) layer between an attached Fresnel, then sealed... The Fresnel tended to even out the central "hot spot" somewhat, the grain disappeared, and the Fresnel about focused the eye to where the focal plane would be on the GG...

A fine grain screen tends to hold more detail on it's surface to see, but dimmer... But I have talked to some photogs that couldn't use bright type screens due to their eyesight issues that didn't mesh with them...

Steve K

Bob Salomon
7-Feb-2018, 12:01
One screen I had seen a long time ago was a blasted glass GG, that had a liquid (oil?) layer between an attached Fresnel, then sealed... The Fresnel tended to even out the central "hot spot" somewhat, the grain disappeared, and the Fresnel about focused the eye to where the focal plane would be on the GG..

Are you talking about the Boss Screen? That had two pieces of glass with a paraffin layer between them. The image was formed on the wax layer.

LabRat
7-Feb-2018, 12:30
“One screen I had seen a long time ago was a blasted glass GG, that had a liquid (oil?) layer between an attached Fresnel, then sealed... The Fresnel tended to even out the central "hot spot" somewhat, the grain disappeared, and the Fresnel about focused the eye to where the focal plane would be on the GG..”

Are you talking about the Boss Screen? That had two pieces of glass with a paraffin layer between them. The image was formed on the wax layer.

I think it was a variation of the Boss screen by someone else, Bob...

I used to assist many commercial studio photographers in the 80's-90's that would buy every gizmo that came out then, and this was one of these...

Bright, but weird if you were used to a standard GG, but the grain and Fresnel pattern mostly disappeared (and still corner fall-off)...

Steve K

Bob Salomon
7-Feb-2018, 12:49
I think it was a variation of the Boss screen by someone else, Bob...

I used to assist many commercial studio photographers in the 80's-90's that would buy every gizmo that came out then, and this was one of these...

Bright, but weird if you were used to a standard GG, but the grain and Fresnel pattern mostly disappeared (and still corner fall-off)...

Steve K

We were the Linhof and Wista distributor then and had just stopped making the Linhof Super Screen about then. So we had experience with virtually all of the enhanced screens on the market. Never saw or heard of 9ne like you mentioned available commercially.

Jac@stafford.net
7-Feb-2018, 13:55
I have a couple Satin Snow 4x5" screens still in the package. (This is not a For Sale)

I'll save my impression because I haven't eyesight good enough to critique. But they are so pretty. Regarding usefulness, perhaps others can comment.

BradS
7-Feb-2018, 15:39
I have a couple Satin Snow 4x5" screens still in the package. (This is not a For Sale)

I'll save my impression because I haven't eyesight good enough to critique. But they are so pretty. Regarding usefulness, perhaps others can comment.

I have and use a couple of Satin Snow screens. They're very good. Unfortunately, they're no longer available.

Keith Pitman
7-Feb-2018, 16:17
Steve Hopf borosilicate glass

Steve Hopf seems to be out of business. I have tried to contact him several times in the last several months with no luck.

David Karp
7-Feb-2018, 16:39
You can find Steve Hopf on eBay as Photofixation. I don't have his email handy now, but I contacted him directly a few months ago and received a very nice new GG from him. I agree, the Borosilicate glass is the best choice.

tom43
8-Feb-2018, 02:09
How das the Hopfglas GG compare to a Maxwell screen?

Whir-Click
8-Feb-2018, 04:53
Maxwell’s 4x5 screens are a fresnel and ground glass integrated into a single piece. This type of “enhanced” focus screen provides vastly improved illumination. Check out Alan Brock’s blog and You Tube review to get an idea.

Hopf’s product is “un-enhanced” (i.e. it’s just glass), but with a very nice grind: the best balance of brightness and sharpness that I have found in a plain ground glass. His borosilicate glass is reputedly stlightly brighter and stronger than regular glass.

The products and price are so different that a direct comparison isn’t really fair. I tried several options, but once I installed the Maxwell screen, I stopped looking for something better.

If you want the best ground glass, go with Hopf. If you want the best focus screen, go with Maxwell.

EdSawyer
8-Feb-2018, 07:11
How would you determine if it's been acid etched?


The sides of the individual grains on the GG have more/less transmission due to the amount of fine grit blasted, but in the old days, some GG's were blasted, then slightly etched with hydrofluoric acid to smooth the grit slightly... (This is a lost art of balancing these points, and now hydrofluoric acid etching is largely banned everywhere...) Some original top GG screens on some RB Graflexes still have these...

EdSawyer
8-Feb-2018, 07:15
The other place that does the same type of screens as Maxwell (I believe both are made by the same company) is Canham. His ground glass/fresnel combo is a one-piece solution also, and quite bright. Cheaper and easier to come by than the Maxwell screen I'd think.

rorye
8-Feb-2018, 09:26
"Steve Hopf seems to be out of business. I have tried to contact him several times in the last several months with no luck."

Oh dear, I hope not, I'm waiting on an 8"x10" GG...

LabRat
8-Feb-2018, 11:28
How would you determine if it's been acid etched?

The etched screens have a slightly glossier surface than just the blasted matte (whitish) surface... The etched surface reflects a little light when held at the right angle, slightly smoother, and holds dust/fingerprints differently...

Viewing through them, colors are more contrasty/saturated, brighter, more dimensional, a lit glassy TV CRT "effect", but with a very pronounced "hot spot" closer to the center... Everything looks brighter, but might be harder to loupe analyze fine detail up-close for focusing... (And maybe a little harder to read viewing up close, but much better viewing at a slightly extended distance...) This is much more of an "aerial image" viewing, rather than an image that just "sits" on the surface of the GG...

One might be able to "fake" this effect by dipping glass GG in a gelatin solution to add a little gloss over blasted GG surface...

Steve K

mmerig
8-Feb-2018, 13:49
"Steve Hopf seems to be out of business. I have tried to contact him several times in the last several months with no luck."

Oh dear, I hope not, I'm waiting on an 8"x10" GG...

I ordered and received a 4 by 5 GG from Steve Hopf in mid-summer 2017 (I actually got two, as the first was a little bit small and he sent it to me for free). The transaction was not the smoothest, and it took an email or two as reminders, but it worked out fine in the end. I like the GG, and Steve too. My impression is that he is not very organized, but means well.