fresnel and ground glass

[maarten m]

i just got a graflok back with a fresnel plate and a groundglass. now i was wondering ...
1. what is the fresnel usefull for? can't you just focus on the ground glass?
2. if you put the fresnel in, how should it be done? on the lensside? or rather on the filmside?
3. what side of the fresnel has to face the ground glass? the smooth surface? or the surface with the "circles" on?

thanks!
maarten.

 

[Doremus Scudder]

There is a ton of information here about this subject. Do a search on Fresnel here and in Google and be prepared to spend some time reading.

To answer your questions in short form:

A Fresnel screen is a lens and brightens your viewing screen. You can just use the ground glass if you like. It will be darker, but many prefer a plain ground glass to a Fresnel due to other problems introduced by it.

The position of the Fresnel depends on the design of your camera. You need to understand how it works and how your camera is designed. If you have a factory-installed Fresnel, use it in the orientation it came in.

All this will become much clearer after you have done your homework.

Best,

Doremus

www.DoremusScudder.com

 

[BrianShaw]

For the Graflock back when used on a Graphic press camera the order is: fresnel on the LENS side with the grooves facing the ground side of the glass -- in other words, fresnel grooves and ground side of glass sandwiched together.

 

[maarten m]

thanks brian and doremus for the answers i needed.
sorry doremus i didn't plough through the whole forum in search of answers.
i tried "42" but it came out blank on fresnel ...
thanks nonetheless to take the time and effort to point it out and answer at least 33% of my questions.

maarten.