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View Full Version : That Technika III Ground glass thing again help.



rknewcomb
8-Jan-2013, 11:47
The early part of this post is here if anyone cares.
http://www.largeformatphotography.info/forum/showthread.php?98402-Linhof-4x5-Technika-III-version-5-Ground-glass-What-to-do-to-replace-one

I received a 4x5 Linhof Technika III "replacement" ground glass from Stephen Shuart. It is close enough to the correct size to fit inside the metal ground glass frame so thats good, but...
The two flat springs that push the glass up against the flat machined surface don't reach far enough to actually push against the glass. The amount of space left in there makes me wonder if this camera originally had a fresnel screen on it.

Did the 4x5 Technika III come with a fresnel and do I understand correctly that it was on the inside (lens side) of the ground glass?

If I buy a generic fresnel and ground glass, who should I contact to put it all together and make sure its all set correctly for sharp pictures?

thanks,
Robert N

Ari
8-Jan-2013, 11:59
I seem to remember that the III did indeed have its fresnel between the GG and lens.
Bob Salomon posted a few weeks back about who is handling Linhof service, now that Marflex is no more.
http://www.largeformatphotography.info/forum/showthread.php?98043-Marflex-retired-Nippon-Photoclinic-Linhof-Wista-USA-service-center

rknewcomb
8-Jan-2013, 13:10
I don't know if I sent them my parts if they would work on it or not, being the age that it is and them new to Linhof.
Robert

Brian Ellis
8-Jan-2013, 17:44
I used S.K.Grimes (www.skgrimes.com) to install and check out a BosScreen on a Technika V some years ago. You probably know of Grimes, they're well known in the LF community for the high quality of their work but they're not cheap. I don't remember what I paid and it would be dated anyhow.

Teodor Oprean
8-Jan-2013, 21:18
I would buy a fresnel from ebay seller "ssoliton11" and install the fresnel behind the groundglass. If needed, you can make extra padding around the edges of the fresnel with small bits of cardboard.

Teodor Oprean
8-Jan-2013, 21:21
Alternatively, if you prefer to work without a fresnel, just cut two strips of cardboard to the necessary thickness and insert them in between the groundglass and the metal springs. You just need a filler material. It doesn't need to be anything fancy or expensive.

Bob Salomon
8-Jan-2013, 22:02
They are not new to Linhof. They have been repairing them for years. They are new only as far as being the official USA Linhof service center.

rknewcomb
9-Jan-2013, 06:44
Maybe someone out there who has a 4x5 Technika III can look at their ground glass and notice if it has a fresnel and see if its on the lens side or viewer side of the ground glass. BTW, this is the Tech III version 5
Thanks!!
Robert

mikezvi
9-Jan-2013, 08:54
Mine did not come with a fresnel, but I bought it used, so who knows if there used to be one there. I have added one in back, but the regular gg always seems to have rested on the springy things.

Cor
10-Jan-2013, 03:07
My Tech III (version 4 I recall) did not come with a fresnell either, and I am quite certain it is still the original ground glass.

Best,

Cor

cyberjunkie
10-Jan-2013, 04:10
My Technika III (5th version, with graflok back and tapered cover/base) came with two ground glasses:
- the original one, with grid (unfortunately broken in two pieces!)
- a replacement one with no grid, of the same thickness, but possibly with a finer "grain" (a little more luminous though with less differentiation between in/out of focus)
NO fresnel, either separate or in one piece with the GG (as in my Pacemaker Speed Graphic).
No traces or any other evidence that it ever had a fresnel before... and the same holds true for the Technikas used by some friends.

I think that the ground glass you got is thinner than the original one.
It is NOT a big problem, as the ground side, where the image is formed, sits on the same plane of the old glass.
The best answer was already given: shim the GG where it is held by the clips.
You just need some cardboard to firmly seat the GG in place.

If you want to go the fresnel route, you don't have to spend much money.
With a 4x5" camera and a 150mm lens, there are good chances that a cheap fresnel (one of those flat reading lenses), cut to size, would work more than OK.
Of course it must be fitted behind the GG.
If you have a small saw at home, it would be almost as easy as cutting cardboard shims, and cheap enough to ditch the fresnel if you find that you don't like how it works.

have fun

CJ

Michael_4514
13-Jan-2013, 07:12
No fresnel on my Tech III either.

Don_Ashcraft
15-Jan-2013, 19:52
My tech III came used (very) with what I believed to be the original fresnel. I removed it when I replaced the broken ground glass and shimmed it as posted earlier. I have always thought the fresnel was added but was told it was added early on possibly as an option. I really had no clue, so I have read this thread with much interest, thanks!

I still have the fresnel. It is dull and blocked a lot of focusing light, so it's not missed much. Personal preference, I guess.

coisasdavida
17-Jan-2013, 15:02
On my Tech III v5 I see two places where a GG could rest. In fact, if mine was a bit shorter on the long side it could rest lower into the frame (closer to the lens), then the springs wouldn't reach it for sure.

With a metal ruler I measured aprox. 4,5mm from the face of a film holder to the film plane. Between the two places I could rest the GG on the frame, I believe that I have it on the right spot. The other option the frame would be around 3mm deep (closer to lens).

I just pulled the GG out to take a look (got it washed with soap too, after all it kind of needed that). When trying to install it back, I noticed that you have to be careful enough, not to let it drop to the wrong surface on one side when fastening the first screw on the spring on the other side. This could have happened to yours.

That bottom rail on the frame could be for a fresnel, but based on my measurements, I believe GG and fresnel should sit on different machined surfaces.