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Bob Hubert
24-Feb-2012, 13:37
I recently purchased some "newly made" ground glass from that auction site and was pretty disappointed. The glass had a milky white color and was not easy to get a good focus. I need to replace the glass on an 8X10 and an 11X14 Century Studio Camera. I have seen a few threads on the forum that mention replacements for specific cameras - but has anyone run across a reliable supplier for custom ground glass that is good quality?

Bob

www.studio-cameras.com

Richard Wasserman
24-Feb-2012, 13:51
Steve Hopf, he is very friendly and easy to work with and make a superior product. http://www.hopfglass.com/

IanG
24-Feb-2012, 14:09
I make my own, have done for a more than a year or two now, that way I get the screens I need and can use, and I'm well into the 100's now :D. More importantlY I control the finess and quality. Steve Hopf makes great screens, I have bought from him in the past and can recommend hm.

However there isn't a perfect screen, some people prefer a very fine milky screen and a big dark clothplus an hout to get adjusted :D It's about finding a good balance that suits you, the way I grind my screens I can use a plain screen in quite low light and it's not too hard to focus. Add a fresnel and it's very easy.

Ian

Lightbender
25-Feb-2012, 16:31
is satin snow still available?

Oren Grad
25-Feb-2012, 16:37
is satin snow still available?

No.

Leigh
25-Feb-2012, 16:52
The glass had a milky white color and was not easy to get a good focus.
Perhaps you received "opal glass".

Opal glass has a distinct milky white surface on one side; the other side is clear.

It's commonly used as the surface for light tables (in large sizes) or light boxes.

- Leigh

TheDeardorffGuy
25-Feb-2012, 17:12
I've been on the search for a few years. I used to by glass from Deardorffs supplier. It was called Satin Ground. I felt it was a nice glass. Their minimum order was 25 sheets and the quality was consistant. Then they changed their minimum to 100 sheets and a few months later they went out of business, I always could grind it myself and started to. I've seen some of Steve Hopfs and it is beautiful. Try his.

Tim Deming
26-Feb-2012, 10:23
I make my own as well. Very easy to do with a little elbow grease and some aluminum oxide powder. I've been using some nice thin glass from surplusshed that works very well for making screens for small classic German folders, which require a very thin screen. It might be too thin for 8x10 though (although it would be very light).

http://www.surplusshed.com/pages/item/m3012.html

cheers

Tim

Ari
26-Feb-2012, 13:22
I have a Wista ground glass for sale; I think it's the best screen available.
Contact me for more details.
If not, Steve Hopf makes good GG, and Yanke brand on eBay is good, too.

wiggywag
10-Jan-2013, 13:59
Have somebody tried the acrylic ground glass that Richard Ritter use on his cameras? How does it compare to Hopf? What do you prefer?

Drew Wiley
10-Jan-2013, 14:20
Per acrylic in general : it's soft and easily scratched, it can bow and not remain flat, and
it's electrostatic and will inherently attract dust. One the plus side, it's hard to break and
a better temp insulator, so less prone to condensation fogging. You can help the static
issue somewhat with antistatic sprays.

David Karp
10-Jan-2013, 23:25
I bought a 5x7 GG from Steve Hopf. I like it a lot. He seems to be a very nice guy. I also have a Satin Snow, which is nice, but by way of comparison, I like the Hopf Glass better. For one thing, he offered the borosilicate glass option, which is stronger than regular plate glass. He also puts a nice grid on the glass if you like that.

cyberjunkie
11-Jan-2013, 01:28
I've been using some nice thin glass from surplusshed that works very well for making screens for small classic German folders, which require a very thin screen. It might be too thin for 8x10 though (although it would be very light).

http://www.surplusshed.com/pages/item/m3012.html


Surplus Shed also sold original Eastman Kodak ground glasses.
They are cheap and surprisingly good.
I purchased some, in 4x5, 5x7 and 8x10 inches, and i regret i didn't buy more.
I checked a few days ago, but the items have a different description, so i am not 100% sure that it is the same stuff.
I took advantage of the discount days (31%, IIRC), ordering some more, along some packs of much needed optical hardware (some tools, non-metric screws, bolts, nuts, nylon set screws, etc).
If the ground glasses presently on sale are of the same quality of the old ones, they win hands down in quality vs price.
A DIY glass COULD be a little cheaper, if you find the aluminium oxide locally.
Getting the two grades of oxide via mail order, and buying a sheet of good glass, makes you very close to what you'd pay to SurplusShed... provided you don't have to grind many glasses.
The compound used to grind engine valves could be easier to find, and could be even free (if you have a friend who repairs auto/moto/truck engines), but i don't think it would work so well..

My experience with custom/expensive ground glasses is very limited, but i recognize that the GG with integrated fresnel that came with my Tachihara is much better than the average glass found on pre-WWII cameras.
Though i don't agree with the notion that "newer is always better".
When i bought my Calumet C1, the GG broke just before shipment. The seller replaced the broken original GG with a Boss Intenscreen, which had a much higher commercial value.
I am not saying it is bad, it has some evident advantages, though i think that sooner or later i will replace it with one of those SurplusShed glasses, because they are a good compromise and i'm used to them.
IF/WHEN a fresnel is needed, there is the simple option of sticking (or holding) a reading glass fresnel on top of the GG, and quickly removing it when you are done. BTW, wide angles are NOT Calumet C1's cup of tea... so a fresnel isn't the most needed accessory :)

These are just personal experience, maybe not even worth the time i am spending at the keyboard. Though i think i have a small advice for your consideration:
before spending good money in a top product, you must know WHY you need it.
The first step in the right direction is to try a cheap-but-good product, and see by yourself if you REALLY miss something.
If you do, how much are you willing to pay for that extra?
The Eastman Kodak ground glasses i got from SurplusShed are a good starting point. They are incredibly better than those dark, milky glasses found on many antique cameras, but they are not on par with the best ones, which sell for much more.
Of course paying or not the premium is up to you, the decision should be largely dependent on your picture-taking habits (that is, the lighting conditions you usually find when shooting pictures).

have fun

CJ

jose angel
11-Jan-2013, 12:27
Per acrylic in general : it's soft and easily scratched, it can bow and not remain flat, and
it's electrostatic and will inherently attract dust. One the plus side, it's hard to break and
a better temp insulator, so less prone to condensation fogging. You can help the static
issue somewhat with antistatic sprays.
My main problem with them is about bow... the ones I have used even in 4x5" (from a well known first brand and very expensive) were useless. My advice is to keep away from plastic screens.

I work in a laboratory, we use pure aluminun oxide (corundum) in several grain sizes. It is easily available. The size of the grain provides a deeper or shallower surface; as Ian says, the difficult thing is to know which grain suit your needs. FWIW, grain sizes between 0.25um (500 mesh) and 250um (60mesh) are quite common.

wiggywag
12-Jan-2013, 03:56
My main problem with them is about bow... the ones I have used even in 4x5" (from a well known first brand and very expensive) were useless. My advice is to keep away from plastic screens.

I work in a laboratory, we use pure aluminun oxide (corundum) in several grain sizes. It is easily available. The size of the grain provides a deeper or shallower surface; as Ian says, the difficult thing is to know which grain suit your needs. FWIW, grain sizes between 0.25um (500 mesh) and 250um (60mesh) are quite common.

Interesting to consider the grain size. What would you consider being the best grain size? Is it harder to focus if the grain size becomes to fine?

jb7
12-Jan-2013, 04:48
Per acrylic in general : it's soft and easily scratched, it can bow and not remain flat, and
it's electrostatic and will inherently attract dust. One the plus side, it's hard to break and
a better temp insulator, so less prone to condensation fogging. You can help the static
issue somewhat with antistatic sprays.

If you were describing Polycarbonate I'd have to agree with you about the fact that it's soft, easily scratched, subject to bowing, and lacking flatness. Polycarbonate can be supplied as a substitute for acrylic if the correct specification is not adhered to, and unless you know the difference, you might conclude that the material supplied as Acrylic is unsuitable.

Cast acrylic, in the appropriate thickness for the size required, is flat and stiff, and harder and more durable than Polycarbonate. Providing it has been correctly stored prior to supply it is as flat as glass, and should maintain that flatness after installation in a camera.

Joe Forks
12-Jan-2013, 04:49
Smaller grain is easier to focus, but it takes longer to grind the screen with smaller grain. So you start say a 5 micron grain and grind for a while, then switch to a 3 micron grain to finish it up. Makes a really nice ground glass.

http://www.largeformatphotography.info/forum/showthread.php?69723-Made-a-ground-glass-yesterday

IanG
12-Jan-2013, 05:13
Interesting to consider the grain size. What would you consider being the best grain size? Is it harder to focus if the grain size becomes to fine?

As Joe says as well it's best to grind with a coarser grit first, 400 grit is ideal ,and finish with 600 grit this gives a mix of grain size and a better alround screen. I make a lot of screens and there's no reason why a home made screen can't equal ant commercial offering. All the screens I male are significantly brighter than the old Kodak and Graflex screens.

Ian

C. D. Keth
13-Jan-2013, 01:03
Smaller grain is easier to focus, but it takes longer to grind the screen with smaller grain. So you start say a 5 micron grain and grind for a while, then switch to a 3 micron grain to finish it up. Makes a really nice ground glass.

http://www.largeformatphotography.info/forum/showthread.php?69723-Made-a-ground-glass-yesterday

Note that a finer glass will be trickier to use with wide lenses because the hot spot will be a lot more pronounced than with a courser glass. This of course won't matter if you don't care for wide lenses or use a fresnel.

Tim Meisburger
13-Jan-2013, 01:21
Ian, can you give a us a note on your technique? Are you using loose grit, or sandpaper?

Denis Pleic
13-Jan-2013, 03:14
Ian, can you give a us a note on your technique? Are you using loose grit, or sandpaper?

Tim, Ian's article can be found here:
http://www.apug.org/forums/forum216/78392-making-ground-glass-focus-screen.html

IanG
13-Jan-2013, 04:13
Thanks Denis, I re-jigged the article slightly for the Lomography magazine.

Tim in Thailand there should be no problem getting powder grits, wet & dry doesn't really work but is excellent for smothing edges.

Ian

Tim Meisburger
13-Jan-2013, 04:30
Okay. Thanks Denis and Ian. I'll see if I can find grit here (the problem is searching in Thai script). I have the worst screen I've ever seen on my old B&J 5x7 and would like to replace it.

IanG
13-Jan-2013, 04:37
See if you can find someone who polishes gemstones, they should be able to give you some or tell you where to get it.

Ian

Tim Meisburger
13-Jan-2013, 08:58
Right. There is a large jewelry industry here so that could work. I'll check.

jose angel
14-Jan-2013, 07:09
Interesting to consider the grain size. What would you consider being the best grain size? Is it harder to focus if the grain size becomes to fine?
I have been out for a while, I see others have responded to your question. I use the pure powder in jet machines, I have never made a GG with them, so I`m afraid I cannot help you.

About acrylic materials; don`t know if the GG I have used were made in acrylic or polycarbonate, anyway; I work with acrylics, and I`d never advice to buy a GG made of it. There are different acrylics, the high quality ones we use are still sensitive to temperature (in fact, it`s our main problem)... In short; for a GG, if you can buy glass, just buy glass.

As mentioned above, any jewelery manufacturing materials supplier should have pure aluminum oxide powder (=corundum). It`s also quite common between dental manufacturing suppliers. Any good chemical product supplier should have it, too.

Ian`s article explains it all. He use silicon carbide powder (=carborundum).