Ground glass

[Professional]

Hey all,

I would like to ask, what is the specifications or materials details about the ground glass? because i have Shen Hao and Speed Graphic, and both are way different for viewing on the ground glass, so are both made from different glass or material?

Can i have DIY glass for my 4x5? I really hate using the dark cloth a lot when my SG is easier in focusing without dark cloth, i stopped to shoot LF because i want to use my field camera and not much interested in my press camera SG/CG, so i hope i can find a solution for that almost darken ground glass for my Shen Hao even i open the lens wide and pointing to light source.

[IanG]

Your Speed Graphic probably has a fresnel, it's this that makes a huge difference to the brightness although screens themselves can vary.

Alternatively look for a Beattie, Maxwell or Boss screen these are about the brightest but they aren't cheap. My best screen is a Wista combination screen it's very bright but by adding new glass screens and fresnels my Crown and Super Graphic are only about half a stop dimmer and I use both hand-held at times focussing on the screens, quick and easy. Adding a new screen and a fresnel made over 3 stops difference compared to the original Graflex screen with the Crown Graphic.

So I'd look for a fresnel first for the Shen Hao. They aren't expensive and the Chinese fresnels are quite good and make a huge difference (about 2+ stops).

Ian

[Ian Gordon Bilson]

This suggestion is very far from State of the Art, but you can judge how useful an excellent fresnel will be, by buying a plastic "Page Magnifier" from an office supplies outlet, cutting it to fit,and laying it on the exterior of your GG.

[Professional]

Your Speed Graphic probably has a fresnel, it's this that makes a huge difference to the brightness although screens themselves can vary.

Alternatively look for a Beattie, Maxwell or Boss screen these are about the brightest but they aren't cheap. My best screen is a Wista combination screen it's very bright but by adding new glass screens and fresnels my Crown and Super Graphic are only about half a stop dimmer and I use both hand-held at times focussing on the screens, quick and easy. Adding a new screen and a fresnel made over 3 stops difference compared to the original Graflex screen with the Crown Graphic.

So I'd look for a fresnel first for the Shen Hao. They aren't expensive and the Chinese fresnels are quite good and make a huge difference (about 2+ stops).

Ian

Well, i have/bought a fresnel to my Shen Hao, it is good one, but still it is not bright as CG/SG, i even tested the glass screen of CG/SG without fresnel and it is brighter than my Shen Hao screen glass with fresnel, and i checked the glass screen of my SH against SG and no match, i couldn't place that SG glass on my Shen Hao, so i was thinking to have another glass screen brighter for my Shen Hao.

Those names you listed sure are so expensive, so that i asked about if it can be done by myself or from some glasses workmen to make one for me, i will keep looking around for good options and so expensive.

[welly]

I bought a custom fresnel from an eBay seller in China. It was cheap (about 100$) and it's really, really bright. The only problem is with the lines of the fresnel when you're using your loupe on it. It makes fine focusing a little difficult. My Toyo camera also has a fresnel which is also ridiculously bright, but much finer lines on to fresnel so I don't have quite the same issue when focusing. The Chinese shop will cut them to size though. Search eBay for fresnels and you'll find them. I do have a preference for straight ground glass but happy enough with the fresnels I'm working with.

[rcmartins]

I bought a custom fresnel from an eBay seller in China. It was cheap (about 100$) and it's really, really bright. The only problem is with the lines of the fresnel when you're using your loupe on it. It makes fine focusing a little difficult. My Toyo camera also has a fresnel which is also ridiculously bright, but much finer lines on to fresnel so I don't have quite the same issue when focusing. The Chinese shop will cut them to size though. Search eBay for fresnels and you'll find them. I do have a preference for straight ground glass but happy enough with the fresnels I'm working with.
I bought a fresnel that is a two-in-one, meaning ground-glass with fresnel. I still have to test it in the open field but it does seem slightly brighter than my Chamonix. One thing that bugged me, though, in this two-in-one plastic is that focusing with the loupe seems to require the loupe to be held at a 30º - 45º in relation to the surface normal. Indeed, even to look at it without the loupe I get the brightest image from viewing angled from above. I was wondering if anyone here has also stumbled upon this effect.
raul

[IanG]

Any fresnel makes using a loupe less easy, however the upside is it makes a screen very much easier to use and focus without a loupe. I don't use a loupe very often, in fact hardly ever.

Maybe the original Shen Hao ground glass isn't that bright, I did make a replacement for one last year that was significantly brighter according to the camera's owner but I never saw the original myself.

I spent quite a bit of time checking and testing various screens, screen/fresnel combinations and composite screens about 5 years ago before making a number of new screens for almost all my LF cameras. I did visula tests with two cameras side by side as well as taking light measurements off the screens themselves. I stopped the lens on my Wista down until it matched the overall screen brightness of my Crown Graphic and original Graflex screen, then checked brightness of the same areas with lenses fully open, the differences matched exactly around 3½ stops, that's like stopping a lens down from f5.6 to between f16/f22

Ian

[Professional]

Well, you are right Ian, the original Shen Hao GG is not bright, so in fact i asked the question or started this thread looking for a replacement, i can't depend on that GG is it is not bright, it will make my shooting as a nightmare and headache, so i better get another one that is bright enough to work with.

I was thinking if i can find those GG not from ebay, but can i be sure about another LF 4x5 GG such as Linhof/Sinar/Ebony to be used on my Shen Hao? Just i am not sure if they are coming on exact same size of my Shen Hao GG size, i tried to place that of the Speed Graphic on my Shen Hao and it was smaller about few mm, so i don't want to make a mistake and buy another 4x5 GG brighter and it may not fit on my Shen Hao one, the fresnel seems working fine and no issue.

[Jerry Bodine]

Here is another option for a replacement groundglass that you may find interesting:

http://www.hopfglass.com/

I saved this bookmark in case I ever need a replacement.

[Professional]

Here is another option for a replacement groundglass that you may find interesting:

http://www.hopfglass.com/

I saved this bookmark in case I ever need a replacement.

Cool, that looks tempting or promising, hope it is really bright and efficient for LF, i will order one sooner or later.

But i really don't know what is the different between Soda-lime & Borosilicate? Are those materials used with making the glass? or are those just additional increments to the glass to give some performance or whatever?

[Professional]

^^^ Never mind, i got the answer from the same site, sorry i rushed to ask.