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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » Short throw Anamorphic Focus

   
Author Topic: Short throw Anamorphic Focus
Don Furr
Jedi Master Film Handler

Posts: 509
From: Sun City, Ca USA
Registered: Nov 2002


 - posted 11-12-2002 10:25 PM      Profile for Don Furr   Email Don Furr   Send New Private Message       Edit/Delete Post 
Which anamorphic lens will focus at 10 feet besides a Schneider.
I'm using a loner pair but at $750 a pop I need to find another lens.

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000


 - posted 11-12-2002 10:51 PM      Profile for Paul G. Thompson   Email Paul G. Thompson   Send New Private Message       Edit/Delete Post 
Not too many will that I know of. Sankor maybe? I have heard some will, but I have no firm experience to back that statement up.

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Aaron Sisemore
Flaming Ribs beat Reeses Peanut Butter Cups any day!

Posts: 3061
From: Rockwall TX USA
Registered: Sep 1999


 - posted 11-13-2002 12:53 AM      Profile for Aaron Sisemore   Email Aaron Sisemore   Send New Private Message       Edit/Delete Post 
You can modify B&L anamorphics to focus that close, if you want to do it on the cheap...

-Aaron

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Jeff Stricker
Master Film Handler

Posts: 481
From: Calumet, Mi USA
Registered: Nov 1999


 - posted 11-13-2002 06:48 AM      Profile for Jeff Stricker   Email Jeff Stricker   Send New Private Message       Edit/Delete Post 
I have adapted a 16mm Sankor 16D anamorphic to a 3 1/2 inch Kolmorgen (35mm) prime lens. (I used some PVC plumbing hardware and some elbow grease with files and other hand tools to accomplish this!) I can focus down to the limit of the Sankor, which is 2 meters.

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Josh Jones
Redhat

Posts: 1207
From: Plano, TX
Registered: Apr 2000


 - posted 11-13-2002 04:25 PM      Profile for Josh Jones   Author's Homepage   Email Josh Jones   Send New Private Message       Edit/Delete Post 
For those of us who have forgotten(namely me) how do you modify the old B&L lenses for short throw?

JJ

------------------
"Film is made of silver, video is made of rust"
'nuf said

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Dan Lyons
Jedi Master Film Handler

Posts: 698
From: Seal Beach, CA
Registered: Sep 2002


 - posted 11-13-2002 06:48 PM      Profile for Dan Lyons   Email Dan Lyons   Send New Private Message       Edit/Delete Post 
Yes please, tell us how. My Pro 35 should be running within the week, and I don't have the $$ for a fancy new scope lens that will do a 13' throw.

Danny

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Don Furr
Jedi Master Film Handler

Posts: 509
From: Sun City, Ca USA
Registered: Nov 2002


 - posted 11-13-2002 08:32 PM      Profile for Don Furr   Email Don Furr   Send New Private Message       Edit/Delete Post 
I have been testing lens tonight and discovered that a "gold" ISCO scope attachment will focus down to at least 10 feet although it indicates on the barrel that it will only focus to 17 feet. It's not as perfect as the Schneider but pretty darn close. I can live with it.
I also would like to hear how to modify the B&L's!
Thanks for all you responded.

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000


 - posted 11-13-2002 08:53 PM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
I could tell you how to modify a TECO but it involves a lathe! The B&L is much simpler but I only vaguely remember the details. What comes to mind is the outer ring coming off...a slot in which a brass ridge slides back and forth as the element unit moves back and forth and that ridge (for lack of a better term) having to be filed shorter so it doesn't bump into the end as soon and allowing the extra range. I will wager if you partly disassemble one (if it's this kind) it will be obvious. Considering the vagueness of this information , extreme caution is advised!


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Pete Lawrence
Expert Film Handler

Posts: 192
From: Middleburg, PA
Registered: Aug 1999


 - posted 11-16-2002 09:02 PM      Profile for Pete Lawrence   Email Pete Lawrence   Send New Private Message       Edit/Delete Post 
If you try this it's strictly at your own risk! But, I've modified two without any problems.

Remove the front locking ring (red-ring) by unscrewing it.

Remove the large rear adjusting ring by unscrewing it off the rear of the lens.

Mark the front moveable lens housing and the rear lens housing so you can re-assemble them in the same position. This is important!!!

Here's the first tricky part. Remove the two brass guides that ride in the two slots. The screws are glued in and can be very hard to break loose. These should already be marked with one or two center punch marks. If not, mark them in some way so they go back together in the same position and on the same side as you originally found them. This is also important!!!

The two halves of the lens will now simply slide apart. The glass won't fall out, unless they have been previously damaged.

Here is the real tricky part. Remove about 1/2" from the front of the silver half (the rear lens) and about 3/8" from the rear of the black half (the front lens). Chase the threads that you messed up during cutting.

The slots on both sides of the rear lens must be lengthened toward the rear of the lens. You may also have to file the rear ends off of the brass slot guides.

Clean all the chips out of the two halves. You may also have to clean the inside lens surfaces.

That's all there is to it! I would recommend you use a lathe or milling machine to do the cuts, but since I didn't have one I used a band saw with a metal cutting blade. No reason a hacksaw wouldn't work if your real careful. I used a file to lengthen the slots.

The modification works reasonably well for a lens that’s considered a paperweight by today’s standards. Your probably outside the design range of the optics for focus, so don’t expect 12 feet to be as good as say 100 feet.

Here is the lens taken apart. The two rings are the pieces that were cut off.


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Bruce McGee
Phenomenal Film Handler

Posts: 1776
From: Asheville, NC USA... Nowhere in Particular.
Registered: Aug 1999


 - posted 11-17-2002 12:32 PM      Profile for Bruce McGee   Email Bruce McGee   Send New Private Message       Edit/Delete Post 
I have one of Pete's lenses. I am going to have to see what it can do at more than 14 feet. It would almost focus down to that length.


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Jeff Stricker
Master Film Handler

Posts: 481
From: Calumet, Mi USA
Registered: Nov 1999


 - posted 11-19-2003 06:41 PM      Profile for Jeff Stricker   Email Jeff Stricker   Send New Private Message       Edit/Delete Post 
Pete, thanks for your detailed instructions. I just modified one with excellent results. Local machinists wanted to charge me an arm and a leg (plus leave my wristwatch [Wink] ) to do the job. So I got brave, and went at the project with a hacksaw. No sweat. I carefully scribed cutting lines to guide me. I wrapped a rag around the pieces and put them in a vice. The entire job took less than two hours including testing (where I discovered that I had assembled the front element upside down!)

I'm very pleased with the outcome, and wish to encourage anyone who may be hesitant to tackle the job. Focuses down to 15' no problem. [thumbsup]

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