Film-Tech Forum ARCHIVE: Lense Repair explanation

This is topic Lense Repair explanation - Truth or just a line? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Paul Konen (Member # 41) on 06-26-2003, 04:17 PM:

I am having to repair my third Schneider Scope Lense due to an element becoming loose within the primary portion. You can actually hear it click when you shake it back and forth.

Here is what the repair facility said about the previous two repairs. Are they just giving us a line or is it really

quote:
The lenses need to be overhauled from time to time. The Anamorphic lens
has a cam follower, and sometimes the timing becomes an issue. It's just
normal for these lenses to need adjustment's. Usually once the
adjustment is done, you very rarely see another problem for a long time.

What are your thoughts?

BTW, the lenses are never removed, disassembled or anything of the sort. Just used in a normal fashion and cleaned when needed.

Posted by Manny Knowles (Member # 1171) on 06-26-2003, 06:12 PM:

I've never heard of this and I've used a variety of lenses. Not even the cheap ones are unstable like that.

It sounds like a line to me but that's just my gut reaction. Still, even if it is "gospel" truth, it would make me think twice about ever installing such a lens.

Could you imagine the headache of having to keep track of lens overhauls for even a small theatre chain? What a hassle that would be!

Meanwhile, how are you supposed to show your scope movies?

Posted by Ken McFall (Member # 845) on 06-26-2003, 06:41 PM:

To be fair.... lenses are subjected to more mechanical stress that in the days of manual lens changes and 20 on 20 off running. Take the Kinoton turret as an example, at least the ones I've seen. They subject the lens to quite a sudden stop, jolt. The lens has to cope with some 2-3 hours of high intensity heat per show day in day out.

Is it any wonder that they 'can' deteriorate quicker than we would like. Short focal length lens are less forgiving than the lenses of ten years ago. They have to cope with much higher demands and therefore will fail just like any other bit of equipment under constant stress.

Do I think this is fair and reasonable.... I'm not too sure but it is a reality we are forced to accept.

Recent years have seen the forced acpetance of great change and greater demands on things that never used to make their existance known. We always took the 'lens' of granted and never questioned its role in the scheme of putting a show on screen.

Now a days it is possibly one of the most important factor's in the end result..... that and light which is the biggest factor in lens deterioration due to heat of the lamphouse.

Crap lens = Crap picture..... sort of.

Posted by Manny Knowles (Member # 1171) on 06-26-2003, 07:02 PM:

Okay...fair enough.

So now I have a few questions for Paul:

(a) age of lenses?
(b) type of turret?
(c) wattage of lamp?

Posted by Mark Gulbrandsen (Member # 72) on 06-26-2003, 07:28 PM:

Actually Schneider had tons of trouble with their scope lenses that were made fomr the early to the mid 80's. At least they ARE repairable. Many scope lenses are not, or require more expensive repair facilities to tackle them. If it was a B&L, KOWA, or other older brand you would be junking it!!! The present Schneiders are really good though and we have little trouble. The latest batch of Schneeider Integrateds looked almost as sharp as the ISCO 5 element Blue Star lens.
Mark

Posted by Manny Knowles (Member # 1171) on 06-26-2003, 11:17 PM:

Mark that's certainly a relief to hear that the new ones are good!

Posted by Steve Guttag (Member # 268) on 06-27-2003, 06:56 AM:

The current Schneider integrateds are indeed good (as is the larger WA lens) but they don't hold a candle to the Blue-Star. Schneider also suffers from the 4-element desease...they don't expand at 2:1...more often than not, they are greater than 2:1.

In the integrated department...Schnieder has an edge since their integrated is detachable just like any full-sized anamorphic.

However, for full-sized anamorphics...get an ISCO Blue-Star...accept no substitutes.

Steve

Posted by Paul Konen (Member # 41) on 06-27-2003, 09:19 AM:

Manny, this is all original equipment from new construction.

Christie P35 Projector with Automatic turrets
Age approx 4 years
Wattage 3000, 4000 consoles.

Thanks to all for your responses.

Posted by Jason Burroughs (Member # 68) on 06-27-2003, 09:47 AM:

Paul,

Sounds to me like someone is trying to pull a fast one on you.

Provided the lenses are not abused, lamps not left on, kids not slamming the turrets shut, lamp focused properly etc, they should be care free for years.

Posted by Gordon McLeod (Member # 33) on 06-27-2003, 10:27 AM:

It is not that uncommon of problem with the Schnieder anamorphics to require tighening. I also have had some that have cracked elements occur with 7K operation