Replace Std Canham GG with my Satin Snow ?

**Ron Bose** · 29-Sep-2009, 07:14

I have a 5x7 reducing back for my 8x10 Phillips, it has been created from a Canham 5x7 back and has a standard Canham GG installed.

I also happen to have a 5x7 Satin Snow which was built for a Canham back and a Canham fresnel/plain glass also for 5x7.

Can someone give me a brief summary as to the pros and cons of each GG in 5x7 ?

For example will a Satin Snow be advantageous over a fresnel ?

Thanks !!

Ron

**IanG** · 29-Sep-2009, 07:29

Easy answer is adding a fresnel can increase screen brightness by around 2½ stops.

So going the other way and using even the best plain glass screen can be a disadvantage.

In general the manufacturers glass/fresnel combinations are the best, unless you go for amore expensive Maxwll, Beatie etc. Some manufacturers combinations are better than my Wista screen is particularly good.

Why don't you test them both it's a two minute job to swap the screens over. A plain screen is better for focussing with a loupe.

Ian

**ic-racer** · 29-Sep-2009, 07:30

So you have both ground glasses and you are asking us?

Personally I'd be interested in how you thought they compared.

**BrianShaw** · 29-Sep-2009, 07:36

I actually measured SS GG vs stock CAMBO GG. The SS GG is very nice image and slightly brighter. Can't remember the measurement but probably not brighter than a fresnel. I really liked the smooth look, though.

**IanG** · 29-Sep-2009, 07:56

Brian and ic are right, compare the screens on their own then with the fresnel.

You may find the best combination is the SS & Fresnel, but then where did Cahnam get their glass ? There may be no difference at all.

Ian