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Murray@uptowngallery.org Joined: 03 Apr 2002 Posts: 164 |  Posted: Fri Jun 06, 2008 1:32 am Post subject: When did Ekt(r)alite Fresnel screens become standard?
I was shopping for a friend overseas who wanted a 4x5 Graflok back because his camera had a groove back for a Grafmatic or something that prevented him form installing standard film holders.
I found one, and the owner says it is from a 1951-ish camera. It has not Fresnel brightener and I want to confirm it's NOT SUPPOSED to before I spend his money (mine first!).
Thanks
Murray |
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pv17vv Joined: 22 Dec 2001 Posts: 255 |  Posted: Mon Jun 09, 2008 6:40 pm
IIRC what I read here ( I think... ), ALL Pacemaker cameras sold with a Graflok came out of the factory with a fresnel, and the position of the GG was calculated accordingly. |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Mon Jun 09, 2008 6:57 pm
Murray, the test is easily applied, hard to describe well.
Take the ground glass off. You'll see that it rides on four (at any rate, that's how many are in the 2x3 Pacemaker focusing panel) bosses. If the bosses are low, perhaps 1 mm high, the focusing panel wants a fresnel. If the bosses are high, perhaps 2.5 mm high, the focusing panel wants no fresnel.
When you put the GG back, don't forget to put it ground side towards the film. |
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troublemaker Joined: 24 Nov 2003 Posts: 715 |  Posted: Mon Jun 09, 2008 9:06 pm
The raised lip or bosses as Dan descibes them, from what I can tell from the examples I have had through here, were present in the Grafloc focussing panels for use with Ektalite screens. The panels intended for use with only a ground glass have had the raised lip milled down flush or nearly so. Therefore the suggestion the Fresnel became standard along with the introduction of the 4x5 Grafloc sounds good to me. |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Mon Jun 09, 2008 9:25 pm
Trouble, I think we agree. I have 2x3 focusing panels with and without fresnel, all with the appropriate bosses, all with the same part numbers. So I'm sure that the designers had fresnels in mind from the first Graflok.
For curiosity, I just checked the bible, 10th edition. It says that the fresnel was optional on 2x3, standard on 3x4 and 4x5 Pacemakers, from the Graflok's introduction. Before that, all sizes had spring backs without Ektalite.
I wonder why they slighted users of 2x3s. Could it be that the 2x3 was, um, the cheapskates' format?
Cheers,
Dan |
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troublemaker Joined: 24 Nov 2003 Posts: 715 |  Posted: Tue Jun 10, 2008 12:39 am
Did I get that backwards, the bosses are milled for the freznel and not for the straight GG install, which would require the raised boss.
So they pull a batch for the straight guys and send the rest to the mill.
I've got both for 4x5's, but have not yet had a 23 series focus panel milled for a fresnel screen. I don't like them anyway, but am sure there area few around. I have seen panels wherefolks have incorrectly put a fresnel under a GG which moves the focus point back beyond the film plane. |
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Les Joined: 09 May 2001 Posts: 2682 |  Posted: Tue Jun 10, 2008 1:45 am
| Quote: | | Therefore the suggestion the Fresnel became standard along with the introduction of the 4x5 Graflok sounds good to me. |
(giggle, giggle) Gralfex never made it that easy.
The Ektalite field screen started as early as Nov of 1949 but only on the reflex side of the camera line (specifically the Super D) The GraFLEX cameras were easier to modify than the GraPHIC camera line.
From my Price Supplements to the catalogs, the first showing of the Ektalite field screen was in June of 1951 for 3x4 and 4x5 Graphic cameras. Previous to this you could buy the screen alone and have your local shop mill down the raised rib or boss to allow space for the field screen to sit in front of* the ground glass. Which means you can find Pacemaker style spring/Graphic backs with Ektalite field screens as well
*Since the camera lens is on the front of the camera, the field screen sits closer to the camera lens or in front of the ground glass.
Since the Graflok back came out in 1950, if you look hard enough you will be able to find Graflok focus screens that were designed to be used without the Ektalite field screen. These will have raised ribs or bosses that the ground glass sits on that are about 2.5mm high.
While troublemaker is on the right track, his statement | Quote: | | "The panels intended for use with only the ground glass had the raised lip milled down flush or nearly so" |
is actually backwards.
Ground glass only=raised rib is high,
Ektalite and Ground glass=rib is low.
I talked with Tim Holden the last historian/employee still around that worked at Graflex about this. It seemed to me that they anticipated the Ektalite field screen being available, because there isn't a logical reason for that boss to be so high when you just have the ground glass. When I asked him if Graflex was being omniscient , he laughed and said, "No, we just got lucky on that one." |
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troublemaker Joined: 24 Nov 2003 Posts: 715 |  Posted: Tue Jun 10, 2008 2:41 pm
Yes, ever bass-ackwards but I noted that. |
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pv17vv Joined: 22 Dec 2001 Posts: 255 |  Posted: Thu Jul 03, 2008 5:29 am
| Quote: | | Since the Graflok back came out in 1950, if you look hard enough you will be able to find Graflok focus screens that were designed to be used without the Ektalite field screen. These will have raised ribs or bosses that the ground glass sits on that are about 2.5mm high. |
Agree, my recently purchased 707211 2x3 is like that. | Quote: | | I wonder why they slighted users of 2x3s. Could it be that the 2x3 was, um, the cheapskates' format? |
Don't know about yours Dan, but mine is definitely bright enough to go without a Fresnel. |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Thu Jul 03, 2008 11:04 am
"Don't know about yours Dan, but mine is definitely bright enough to go without a Fresnel."
With normal and longer lenses, absolutely. But with lenses much shorter than normal the fresnel -- I have focusing panels with and without -- does brighten the corners.
Cheers,
Dan |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Fri Jul 04, 2008 7:03 am
| Quote: | I wonder why they slighted users of 2x3s. Could it be that the 2x3 was, um, the cheapskates' format?
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From talking to local photographers (northern arkansas) in the late 50's and early 60's I speculate that the newly developed Ektalite Field Screen first applied to the new Graflex SLR was incorporated into the most popular/highest selling format cameras first then applied to the lower demand format cameras. |
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