Film-Tech Forum ARCHIVE: Photo mask by Todd-AO to boost the high end output to 0dB at 12.5K and -1dB at 16K

This is topic Photo mask by Todd-AO to boost the high end output to 0dB at 12.5K and -1dB at 16K in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Thomas Hauerslev (Member # 566) on 02-21-2003, 11:19 PM:

I'm curious to know how many of FT´s members who requested the new Todd-AO masks for the DP70.

The photographic mattes were provided free to anyone who asked for them in return for a short written evaluation - good or bad - of their performance. So please remember to send Dan Leimeter your evaluation of the slits.

Please send the evaluation to:

Todd-AO Studios
Att: Dan Leimeter
900 North Seward St.
Hollywood
CA
USA

Posted by Brad Miller (Member # 2) on 02-22-2003, 01:41 AM:

That's an excellent and desperately needed addition to the AAII. I didn't even know that was available. Still, can that exciter put out enough light through that slit to reach Dolby level?

Posted by Steve Kraus (Member # 476) on 02-22-2003, 10:25 AM:

No, you have to install a Gemini bulb as an exciter!

Just kidding! [Big Grin]

I know of the new masks but haven't seen or heard one used. But I think it's wonderful that people at places like Todd-AO no less continue to advance this great machine.

Posted by Gordon McLeod (Member # 33) on 02-22-2003, 11:26 AM:

I used them with some jax lights with them with no probs

Posted by Christopher Seo (Member # 7) on 02-22-2003, 04:12 PM:

Hmm... this modification seems simple enough, and so much better, that I wonder why they didn't use it in the first place?

Posted by Greg Mueller (Member # 17) on 02-22-2003, 04:45 PM:

I use one. It works as advertised. The problem I had was getting enough light to get to Dolby level. It turned out that the light pipe/condenser lens train was goofed up and after replacing that, it was clear sailing. Very nice boost on the high end

Posted by Gordon McLeod (Member # 33) on 02-22-2003, 05:51 PM:

It wasn't used in the first place as the then academy curve didn't want extended high end. That was also why the Simplex and RCA slits were in some cases 1.5mil wide

Posted by Mark Gulbrandsen (Member # 72) on 02-25-2003, 07:10 PM:

Actually to get the best possible performance fomr the DP-70 optical sound reproducer you have to throw out all the stuff thats there now and go to new style LED reverse scan. There are several options for reverse scan on the DP-70 that are available including one new option that may appear at this years Showest. In alot of cases the old light pipe and optics does not allow enough light through for the narrow slit. Sometimes you end up running the preamp gain way high and can barely make it. The JAX light is another option and it now has a fully balanced pre-preamp for much lower hum and noise. Unfortunately though you are still stuck with the old optics here as well, but a fibre optics new light pipe is provided with the US JAX Light.

We recently rebuilt a batch of DP-70's in the CLACO shop for a project and we were told by Todd-AO that no more slits were available. Donno if they made another batch recently or not, but we had a full sheet of them reproduced by a local graphic arts person if anyone needs them.

Mark @ CLACO

Posted by Gordon McLeod (Member # 33) on 02-25-2003, 07:35 PM:

Mark said"Actually to get the best possible performance fomr the DP-70 optical sound reproducer you have to throw out all the stuff thats there now and go to reverse scan"
The DP 70 was always reverse scan [Big Grin]

Posted by Mark Gulbrandsen (Member # 72) on 02-25-2003, 07:36 PM:

Thats not what it says.....show me where it says that......
You've been stirring up way too many Martinis tonight!!
Mark

Posted by Gordon McLeod (Member # 33) on 02-25-2003, 07:48 PM:

Mark that is cheationg you edited your post after mine [fu]

I just happened to have cut and pasted your post [Big Grin]

and verified it against the cached page
since this is visible light I gues your were caught "RED" handed [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 02-25-2003, 07:49 PM:

Ahhh Gord, You're just too Smart for me...
Mark