8mm Forum: Problem With Buhl Anamorphic Len's

This is topic Problem With Buhl Anamorphic Len's in forum 8mm Forum at 8mm Forum.

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Posted by Tom A. Pennock (Member # 202) on April 10, 2008, 11:56 PM:

I bought this len's kit for $300.00 from Dave Thomas Films in 1997. I never tried it out. I decided to not get into Super Eight scope but to go directly into 16mm format. Anyway my friend Larry Arpin bought this len's kit from me but Larry say's it won't focus. Larry said he think's it's missing an element. I never used this lens so I don't know how these work. Can someone help to let us know if indeed Dave Thomas did not sell me the complete kit or? I have no problem with a refund less postage to Larry but I want to know how this len's and stand are supposed to work. Help Please!!!
Best, Tom Pennock

Posted by Dan Lail (Member # 18) on April 11, 2008, 12:59 AM:

Tom,

Do you know if Larry has ever used a scope lens before? Maybe he will chime in and let us know. Usually there is a setting adjustment on the lens(in feet or meters). This should be set to the distance from the prime lens to the screen. After this is done, focus the prime lens by itself, then mount the scope lens in front of the prime. Then while projecting a film you can tweak the focus adjustment on the projector if the image is not sharp enough. [Smile]

Posted by Tom A. Pennock (Member # 202) on April 11, 2008, 10:39 AM:

Thank's Dan!
I will see if I can get Larry on here. It is indeed a focusing problem.
Best, Tom

Posted by Hugh McCullough (Member # 696) on April 11, 2008, 05:04 PM:

The correct way to set up an anamorphic lens is to use a loop of 35PA test film.
As these are not available for gauges under 35mm you have to use a little ingenuity.

Lace up the film, project, and focus the image without the anamorphic, then move the framing until you are projecting a frame line.

Set the anamorphic focus to it's smallest setting.

Swing the anamorphic up in front of your normal lens.
The picture should be well out of focus.

Use the projectors focus control to get the frame line in focus as sharp as possible.

Now slowly turn the anamorphic focussing ring until the whole picture comes into focus.

You might find that the distance marked on the anamorphic doe's not tally with the throw distance.

Do not worry about this as you have now set the lens up for it's optimum performance, at that throw distance, by focussing through the lens.

Posted by Tom A. Pennock (Member # 202) on April 11, 2008, 05:10 PM:

Dan and Hugh:
Thank's for your postings! I just talked to Larry on the phone hoping to figure out the problem but he has returned the len's today for a refund. He did provide pictures to me with the lens, stand and the scope image from The Sound Of Music. If someone would e-mail me I would be grateful to have someone look the screen captures over. Thank's!!!
Best, Tom (tapennock@aol.com)

Posted by John Whittle (Member # 22) on April 11, 2008, 06:45 PM:

Tom,

If your Buhl lens is like the ones I have, they are really just Sankor 16C elements mounted in a new tube without a focusing ring. You loosen the set screw and then once the lens is adjusted you set the screws again. I think they were inteneded for close focus use on Telecines since the ones I've seen came from military surplus.

John

Posted by Tom A. Pennock (Member # 202) on April 11, 2008, 09:32 PM:

Hi John:

Thank you for the information!

Sincerely,

--Tom

Posted by Larry Arpin (Member # 744) on April 11, 2008, 09:38 PM:

I am very familiar with scope lenses and how to focus them properly. Unfortunately, I tried everything to try and focus the lens. It just seemed as though an element was missing to bring the focus in. It wasn't just soft it was way out of focus and nothing I did would bring it in. Here are pictures of the lens:

Posted by Dan Lail (Member # 18) on April 11, 2008, 11:02 PM:

Larry, maybe someone disassembled it in the past and did not reassemble it correctly. [Confused]

Posted by Larry Arpin (Member # 744) on April 11, 2008, 11:47 PM:

Dan-That's possible as it actually comes apart into 2 pieces and there is a machined part that allows the front element to slide in and out. To me this seemed unusual as I have only had a lens that rotates to focus. I wish I had taken more pics of just the lens but I was just thinking of Tom to put it on an auction.

Posted by John Whittle (Member # 22) on April 11, 2008, 11:49 PM:

Larry
That lens is just like the pair I have. To focus them you have to loosen the allen head screws and then the two elements (FRONT AND BACK) are free and you need to both slide and rotate to get them into focus. The think that often happens with the Sankor and Kowa lenses is they will loose their vertical alignment and then "go soft" the Buhl design lets the user set the lens but it is frustrating because you have to both get the distance between the two elements and the rotation of the front to back right and then set the screw. No difficult if you have four hands, but otherwise a bit challenging. There is nothing missing there is just a front and back element each of which is made up of two pieces of glass cemented together.

You can "tune up" the Sankor lenses by removing the outer focus collar and then loosening the brass pieces that keep the front and back elements in line and it only takes a thou or so to see the difference in focus. The lenses can produce a sharp good contast scope image.

John

Posted by Dan Lail (Member # 18) on April 12, 2008, 12:46 AM:

There! John Whittle to the rescue once again. This man is a wealth of information. Thanks, John. [Smile]

Posted by Tom A. Pennock (Member # 202) on April 12, 2008, 02:32 AM:

John is a Genius!!! Thank you John!!!

Larry, I am willing to re-send it and absorb the postage for a second time if you still want it. Otherwise I would have to list it and all that. Plus currently I don't have a digital camera. This would be a problem for me to list it with zero pictures.

Please let me know.
Best, Tom

P.S. I thought maybe you could take some more pictures for me!
Thank's!!!

Posted by Tom A. Pennock (Member # 202) on April 12, 2008, 12:20 PM:

ANY TAKERS? MINT CONDITION!!!
BUHL SCOPE LEN'S, LEN'S BRACKET & STAND, "THIS IS SCOPE" SUPER EIGHT SCOPE TEST FILM.
$100.00 OR BEST OFFER!!! ORIGINAL COST FOR THIS KIT WAS $300.00!!!
I AM MOVING INTO 16MM COMPLETELY & NO LONGER NEED THIS SCOPE KIT FOR SUPER EIGHT.
GOODBYE TO SUPER EIGHT FORMAT & HELLO TO 16MM FORMAT
THANK'S, TOM PENNOCK

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