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1banjo
Joined: 16 Nov 2008 Posts: 492 Location: kansas
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Posted: Sat Feb 04, 2012 8:33 pm Post subject: Fresnel Lens 23 {2 1/4 x 3 1/4} |
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I have been looking for some time on ebad for Fresnel Lens
for my Century ! they never come up all I need is the Fresnel Lens
as mine is mising ! I need two so I can put them back in so my foucsing
will be right.
Banjo |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Sun Feb 05, 2012 12:01 am Post subject: |
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Hey Banjo, if you have 2x3 focusing panels made for fresnel and made for no fresnel, measure the heights of the bosses the GG and fresnel (if one is supposed to be there) sit on. The difference between with and without will tell you how much to shim the GG so that a focusing panel made to have a fresnel will focus correctly without one.
I'm feeling lazy and and am doing other things just now. If you don't have 2x3 focusing panels of both types, let me know and I'll check mine, I'm pretty sure I have at least one of each. |
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1banjo
Joined: 16 Nov 2008 Posts: 492 Location: kansas
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Posted: Sun Feb 05, 2012 12:17 am Post subject: |
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thanks Dan
I have some that never had a Fresnel & have 2 with out the Fresnel
that need them. I like using Fresnel so I need to find 2 to put back
in the two backs that are missing them so I can go back to using them the way they were to be used! |
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Joey Anchors
Joined: 18 Jan 2012 Posts: 65 Location: Silver City, NM
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Posted: Sun Feb 05, 2012 12:47 am Post subject: |
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how do you tell if your back had one or not? |
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1banjo
Joined: 16 Nov 2008 Posts: 492 Location: kansas
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Posted: Sun Feb 05, 2012 1:47 am Post subject: |
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2 ways # 1 shot some film that you know should be in foucss
and prosses and see
#2 measure the height from a neg. in a film holder to face of the holder
then measure the height from the glass to trhe face of the back
they should both be about the same or about 4.8mm on a 23 {2 1/4 x 3 1/4}
and a back that use a fresnel in front of the Grand Glass
measure's about 3.42mm
BUT some people have add a fresnel to a back that was made for a
fresnel. they need to put the fresnel on top of the glass closer to you out the out side
NOT on the in side like the backs that are made for fresnel in front or on the inside |
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Henry
Joined: 09 May 2001 Posts: 1636 Location: Allentown, Pennsylvania
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Posted: Sun Feb 05, 2012 3:17 pm Post subject: |
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I obtained a fresnel, also called an Ektalite screen, some years ago from Robert Pins in NJ (believe he's no longer doing business), and was able to mount it on my Century without altering the position of the gg. I *very* carefully trimmed the edges of the fresnel, which is plastic of some kind, leaving a little projecting tab at each corner. These tabs fit neatly into the cut-outs at the corners of the focusing frame window. The whole "sandwich" uses the original retaining clips and screws as before. The ground glass sits in its original plane, in contact with the frame.
BTW, if you mount the fresnel inside the gg, i.e., closest to the viewer (meaning you, the photographer), and plan on using a loupe, you will certainly scratch the fresnel surface, which is very tender. I wouldn't recommend this practice! I think there is general agreement that the "stacking order" is fresnel smooth side facing lens, fresnel ridged side (the fresnel) against the ground surface of the ground glass, smooth side of glass closest to viewer.
P.S. Dan Fromm, did you know Pins? I think I met him once at a Delaware Valley camera show in Trevose, but I stopped getting his catalogs in the mail some time ago. Is he still around? |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Sun Feb 05, 2012 4:47 pm Post subject: |
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Yes, Henry, I knew Mr. Pins. Haven't seen him for years, have no idea what's become of him. |
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