"Bright" Screens and Shen Hao

[paul_frank]

Forgive me if this is a stupid question, I've read the archives and still am unsure.

 

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I have the Shen-Hao 4x5 field camera. Do I need a "bright" screen specifically built for my camera, or only built for a graflok back? Do the fresnel lenses or "bright" screens make a real difference? I shoot with just a cloth using 47/5.6, 90/6.8, and 150/5.6 lenses. The wideangles are particularly troublesome, especially in low light. Is there a ~$100 solution? Thanks in advance.

[jason_greenberg_motamedi]

Paul,

 

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It depends upon which 'bright screen' you want. You will have to have a

custom made Bosscreen. Most fresnels should just drop in. I seem to recall

that Badger had something specifically for the Shen-Hao. In any case,

measure your back carefully (buy or borrow a calipers) and call around. Note

that the 'grafloc' back ground glass size is not standard, so you can't just buy

a screen made for one. You must measure, or call Jeff at badger.

 

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I much prefer a bright screen over ground glass, but this is a matter of

personal preference. I can't say if you will like it.

 

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jason

[eugene_singer]

Paul, before you invest in a Bosscreen, try placing a dab of Vaseline

on the frosted side of the groundglass, then wipe the Vaseline in a

circular motion with Kleenex until it appears to be completely wiped

away. You will find that this seems to give a brighter, finer grain

effect to the groundglass. It's the same effect as the Bossscreen. A

Fresnel focusing screen, placed on the smooth side of the groundglass

is the best brightener for use with wide angle lenses. Look for a

plastic one, there should be one available to fit the Shen Hao. It

will fit on the groundglass, not on the graphlock back. Wisner sold

one for under $100 for his 4x5 cameras.

[eugene_singer]

Paul, a P.S. to my post: I just accessed the Wisner website

(Wisner.com). looking under accessories, he lists his snap-in plastic

Fresnel screen at $80. I have been looking for the type of plastic

sheet that you place on a printed page. It enlarges the printing, for

people who have difficulty with their eyesite. I think that this type

of material can be cut to fit the groundglass on my Shen hao. I have

checked with Barnes and Noble and Office Depot. So far, no luck.

[david_willis]

Eugene, you can get a fresnel page magnifier at Edmund Scientifics.

The web site is

 

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www.scientificsonline.com

 

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The part number for an 11" square fresnel is CR30708-77 and the cost

is $4.95.

 

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You can get a 7x10" 0.6 mm thick acrylic fresnel for $4.95 too. The

part is CR30384-54.

 

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If you want more expensive, optical quality fresnels, go to

www.edmundoptics.com and search for fresnel. Be warned, they can be

pretty expensive.

 

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DW

[paul_frank]

does adding a fresnel in front of the GG cause any focus shift?