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robk331
2-Apr-2018, 14:28
Hi All,

I managed to break the ground glass on my 14x14 camera. Can anyone recommend a supplier for a custom-made replacement?

Thanks

Rob

Roger Thoms
2-Apr-2018, 17:52
http://www.largeformatphotography.info/forum/showthread.php?144632-Ground-Glass-focusing-screens-including-custom-sizes-from-Young-Camera-Company&highlight=Ground+glass

Here's one source.

Roger

Ray Van Nes
2-Apr-2018, 17:54
I just built a 5 x 12 camera and I sourced my ground glass on ebay. I found a vendor who was making 5x7 and asked if they could do 5 x 12 - no problem.

rorye
3-Apr-2018, 16:14
I'm very pleased with the 8"x10" gg I recently got from Steve Hopf
https://hopfglass.wordpress.com/

gphoto
16-Apr-2018, 12:32
Make your own, I just one for my 16x20 and it was remarkably easy and the screen is bright. Total cost was maybe 20$ for glass and grinding compound. And an hour or so of elbow grease.

I followed Ian's directions https://www.lomography.com/magazine/52936-grinding-your-own-focus-screen

rakeshnagar
30-Apr-2018, 23:44
Pl contact Rakesh rakeshcw@gmail.com

Ron (Netherlands)
1-May-2018, 14:56
Make your own, I just one for my 16x20 and it was remarkably easy and the screen is bright. Total cost was maybe 20$ for glass and grinding compound. And an hour or so of elbow grease.

I followed Ian's directions https://www.lomography.com/magazine/52936-grinding-your-own-focus-screen

+1 .......I've done a number of ground glasses myself
even a little one for an old Rolleicord that was missing a ground glass...
https://www.flickr.com/photos/zorki_2007/albums/72157660810886723

andrewch59
2-May-2018, 07:12
+1 .......I've done a number of ground glasses myself
even a little one for an old Rolleicord that was missing a ground glass...
https://www.flickr.com/photos/zorki_2007/albums/72157660810886723

Much easier and cheaper to make your own. Two days ago I broke the GG on a brand new 8x10, two hours later I had another one fitted. I used glass I had cut for collodions.

Randy Moe
2-May-2018, 08:33
+1 for Ian's tutorial.

I won't buy another, too much fun making them. I watch a movie while grinding and soon it is done.

I buy grit here. Telescope DIY supplies. http://www.willbell.com/atmsupplies/atm_supplies.htm

Tim V
2-Jul-2018, 04:26
Has anyone had contact with Steve Hopf of late? I’ve emailed the address on his temporary site but had no reply. I need a new screen for my 8x10 Gibellini as it has a horrible plastic stock screen...

Edit: heard back from him.

jim10219
2-Jul-2018, 13:57
I have to say, I enjoy my DIY projects and always seem to have at least one going on (just finished a bard door tracker yesterday!). Some of my projects are kind of difficult and require a good bit a patience, knowledge, specialized tools, dexterity, creativity, etc. However, this one is different. As long as you have the glass cut down to size by the person you buy the glass from (most hardware stores will do this for free), it really is a simple, anyone can do it, type of project.

I did screw it up once though. I used 1500 grit the first time I tried, and that was too fine of a grit and didn't make the glass opaque enough. As such, I could see the back of the lens better than I could the projected image through the ground glass. But it was an easy fix. I just reground the same piece of glass with 600 grit and had a perfect ground glass in about 20 additional minutes. That's what makes it so easy to do. Unless you drop it or accidently grind both sides of the glass, all you have to do to fix any problems or imperfections is keep grinding.

Jac@stafford.net
2-Jul-2018, 17:02
In my humble experience, a ground glass (GG) can be ground to be too smooth. An example might be Satin Snow which is so finely surfaced that focusing is difficult because it is too difficult to see the differences due to the depth of the glass. I dearly welcome correction to my opinion. Thank you.

Randy Moe
2-Jul-2018, 17:12
And too coarse. It may in the eye of the beholder.

I have a very course OE 4x5 Linhof GG that is the other way. I like it for its own beauty.

Tim V
2-Jul-2018, 23:25
Thanks for the replies. Steve sent an email, very helpful. As much as I’d like to give making my own GG a go, I don’t have the time. I’ll get one of Steve’s, but which one... standard or borosilicate, do people think the latter is worth the premium? I accept there is an element of subjectivity, but on the other hand anything would be better than my current plastic one...

Tim V
19-Aug-2018, 12:41
I received my new screen from Steve last week. After installation, I can confirm that it's a complete revelation in comparison to the original screen I was using. Lovely and sharp, exceptionally easy to see the exact focus point, and much brighter. Money well spent in my book, so very happy.

gphoto
29-Aug-2018, 08:43
Steve's screens are definitely top notch, I have one for my 4x5 and it's super bright and I think the extra for the boro glass is probably worth it if you travel a lot with your camera, not so much if you're just in the studio.

Bob Salomon
29-Aug-2018, 09:46
Steve's screens are definitely top notch, I have one for my 4x5 and it's super bright and I think the extra for the boro glass is probably worth it if you travel a lot with your camera, not so much if you're just in the studio.

Why? Borosilicate glass, or Pyrex, is good against thermal expansion. A common thing for cookware or labware, but it is not shatterproof or crack proof. So why pay for it for a camera screen?

Nodda Duma
29-Aug-2018, 12:35
Borosilicate vs soda lime glass is a whiter glass (better for gauging color cast) and should take a nicer grind because of its greater hardness.

Bob Salomon
29-Aug-2018, 12:59
Borosilicate vs soda lime glass is a whiter glass (better for gauging color cast) and should take a nicer grind because of its greater hardness.

Then why donít
Linhof, Sinar, Arca, etc. use it? Considering the cost of their cameras it would have added a negligible amount to the final cost. Especially as Schott was involved in its manufacture!

I could see a benefit to some type of tempered glass but ground float glass works just fine!

Nodda Duma
29-Aug-2018, 13:03
Youíd have to ask them.

Btw borosilicate isnít the same as Pyrex. Pyrex is just one form (Corningís version, to be absolutely correct) of several different makeups. Sort of like there are many different 100 speed B&W films.

Bob Salomon
29-Aug-2018, 14:09
Youíd have to ask them.

Btw borosilicate isnít the same as Pyrex. Pyrex is just one form (Corningís version, to be absolutely correct) of several different makeups. Sort of like there are many different 100 speed B&W films.

From Wikipedia:

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Borosilicate glass

Guitar slide made of borosilicate glass
Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (~3 ◊ 10−6 K−1 at 20 įC), making them resistant to thermal shock, more so than any other common glass. Such glass is less subject to thermal stress and is commonly used for the construction of reagent bottles. Borosilicate glass is sold under such trade names as Borcam, Borosil, DURAN, Suprax, Simax, BSA 60, BSC 51 (By NIPRO), Heatex, Endural, Schott, Refmex, Kimble, MG(India) and some (but not all) items sold under the trade name Pyrex.

Contents
History Edit

Borosilicate glass was first developed by the German glassmaker Otto Schott in the late 19th century. Otto Schott was also the founder of today's Schott AG, which has sold borosilicate glass later under the brand name DURAN. As part of an equity carve-out in 2005, the DURAN Group was founded and the manufacture of Duran was transferred to it. After Corning Glass Works introduced Pyrex in 1915, the name became a synonym for borosilicate glass in the English-speaking world. However, borosilicate glass is the name of a glass family with various members tailored to completely different purposes. Most common today is borosilicate 3.3 glass such as Duran, International Cookware's Pyrex, NIPRO BSA 60, and BSC 51.

The European manufacturer of Pyrex, International Cookware, still uses borosilicate glass in its Pyrex glass kitchen products,[1] but the U.S. manufacturer of Pyrex kitchenware now uses tempered soda-lime glass.[2] Thus Pyrex can refer to either soda-lime glass or borosilicate glass when discussing kitchen glassware, while Pyrex, Bomex, Duran, TGI and Simax all refer to borosilicate glass when discussing laboratory glassware. The real difference is the trademark and the company that owns the Pyrex name. The original Corning ware made of borosilicate glass was trademarked in capital letters (PYREX). When the kitchenware division was sold, the trademark was changed to lowercase (pyrex) and switched to low thermal-expansion soda-lime glass. The scientific division of Pyrex has always used borosilicate glass[3].[citation needed]

In addition to quartz, sodium carbonate, and aluminium oxide traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. The composition of low-expansion borosilicate glass, such as those laboratory glasses mentioned above, is approximately 80% silica, 13% boric oxide, 4% sodium oxide and 2Ė3% aluminium oxide. Though more difficult to make than traditional glass due to the high melting temperature required, it is economical to produce. Its superior durability, chemical and heat resistance finds use in chemical laboratory equipment, cookware, lighting, and in certain kinds of windows.Ē

How does the extra cost benefit a ground glass focusing screen?

Nodda Duma
29-Aug-2018, 15:33
Ok Bob, you win. You can keep on arguing whatever point youíre trying to make. Iíll just keep drinking my beer I have here.

Drew Wiley
29-Aug-2018, 16:39
Convenience of grinding might have something to do with it. Sinar and other big companies had to do it in volume, presumably automated in some manner. Cutting harder or tempered glasses is also trickier and would have to factor into cost, plus the outrageous predictable markup such companies once expected to get for replacement components. In this respect, the need for volume production would probably have dictated choices. Or maybe they just had an inside deal with a particular glass distributor. I dunno. But they weren't either a charity or somebody with a moonlight business in their garage who sold direct to the end user. Sinar glass is only slightly different functionally than Satin Snow, but I actually prefer the latter. Haven't tried cooking on either!

Bob Salomon
29-Aug-2018, 16:53
Convenience of grinding might have something to do with it. Sinar and other big companies had to do it in volume, presumably automated in some manner. Cutting harder or tempered glasses is also trickier and would have to factor into cost, plus the outrageous predictable markup such companies once expected to get for replacement components. In this respect, the need for volume production would probably have dictated choices. Or maybe they just had an inside deal with a particular glass distributor. I dunno. But they weren't either a charity or somebody with a moonlight business in their garage who sold direct to the end user. Sinar glass is only slightly different functionally than Satin Snow, but I actually prefer the latter. Haven't tried cooking on either!

Drew, most camera manufacturers donít grind their glass, they buy it, as they do many other components of their finished product.

Linhof does not make the castings for their bodies, they finish the castings that are supplied by their sub suppliers. Before the law suit Linhof made parts for Sinar.

So, if this gg material is so superior the camera manufacturers could have just as easily supplied it.

As an example, Minolta developed a very bright and contrasty glass that they sold to both Hasselblad and Rollei for their 6x6 SLR cameras. Both companies put their own name on it and sold them as an accessory at a much higher cost.
There is no reason why this could not be done by the large format companies if this type of gg is truly superior.

Fresnel Optics made a tidy amount selling enhanced systems under their subsidiery, Beattie- as the Beattie Screen; by us as the Super Screen and by other companies offering a Fresnel screen with a frosted focusing surface on one side.

But the major camera manufacturers did not offer these systems, why?

Bob Salomon
29-Aug-2018, 16:56
Ok Bob, you win. You can keep on arguing whatever point youíre trying to make. Iíll just keep drinking my beer I have here.

Iím not trying to argue with you, but I donít see your point! Better color is nonsense since the vast majority of color shot on view cameras have always delivered what the shooter needed without exotic glass types! Especially ground glasses supplied on cameras for the past couple of decades.

Drew Wiley
30-Aug-2018, 17:38
Bob, I have no idea why Sinar discontinued their wonderful Norma tapered bellows and replaced it with the less versatile, greater-flare box 4x5 bellows, except for one obvious reason - cost. Make a bellows a mile long and slice it up as needed ... way more cost effective than the first version. I even have a 28 inch Horseman box bellows that fits Sinar. Wonder if I'll ever use it again, since I've given myself a Norma with two mint tapered bellows for a retirement present. But Sinar ground glass is rather hard and brittle. I've had to grind rather than cut it down to size to fit non-Sinar backs. And I have gear to otherwise
cut tempered glass.

Mike in NY
11-Mar-2019, 19:56
I agree with others; making your own gg is pretty straightforward. I'm so accustomed to cutting glass for my wet plates, and sanding my 19th century furniture reproductions, that making my gg was easy the first time I tried it. I have to admit, though, that buying is also pretty expedient, and you'll know it's ground properly.

Mike in NY
11-Mar-2019, 19:58
Ok Bob, you win. You can keep on arguing whatever point you’re trying to make. I’ll just keep drinking my beer I have here.

Pass me one, will ya?

Dave Wooten
13-Mar-2019, 13:17
Hopf made a beautiful 5x7 for my Dorf

Jac@stafford.net
13-Mar-2019, 13:25
What size GG do you need? Place a Want to Buy in the appropriate sub-forum and I think you will be happy.