Search for brighter ground glass for Intrepid 4x5

[BradS]

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]

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]

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]

How das the Hopfglas GG compare to a Maxwell screen?

[Whir-Click]

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]

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]

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]

"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]

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]

"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.