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Extracts and longer parts of in70mm.com may be reprinted with the written permission from the editor.
Copyright © 1800 - 2070. All rights reserved.

Visit biografmuseet.dk about Danish cinemas

 

Modernizing the DP70
The Story of the Todd-AO Projector

Read more at in70mm.com
 
Written by: Thomas Hauerslev Date: 14.08.2019
DP70 with internal DTS reader. Image by Mark Gulbrandsen

From the beginning more than 50 years ago, the DP70 has been considered one of the best projectors ever made. Despite that, Philips continued to improve the machine until production ended around 1966. Since then, and especially in the 1990s, the DP70 is still being upgraded, by Kinoton and other private enterprises.

This page will show some examples.

DP70 RED-LED reverse scanner
 
More in 70mm reading:

DP70 / Universal 70-35 / Norelco AAII - The Todd-AO Projector


Todd-AO
70mm Projectors


Internet link:


kinoton.de
Philips Museum
 
A reverse scan modification is available from Claco Equipment and Services (USA). It is based on the original soundhead/ stabilizer and is the only reverse scan modification that allows use of the no-contact sound drum as designed by Phillips. It also allows the use of DP70 machines with the Cyan Dye soundtracks.

The GST LED reverse scan/Jax Light combination allows another full octave of high frequency through to the processor extending hf response to 16kHz with little or no slit loss compensation at all. This upgrade, as well as Kinoton's Dolby Digital upgrade makes it very difficult to tell if you are listening to analog SR or digital in many cases. See DP70 RED-LED reverse scanner
 
 
DP70 with reverse scan head. By internal DTS reader. Image by Gerard Bierling

I did this reverse scan for the DP70 and can tell you that this photo was taken during the first test in Bioscoop Catharijne in Utrecht which was a success and I made another 4.

Gerard Bierling's DP70 reverse scanner

 
 

870 Special Venue

 
Projector no. 1754 converted to the 870 format by Ciné Matériél in Paris, France. Note missing magnetic cluster and enlarged sprocket. Picture by Francois CARRIN.

There are at least two examples of DP70's which have been converted to the 870 format. One 870 DP70 projector was offered at a price of USD 9995.00 dollars from Vistascope Corporation in Atlanta, Georgia, USA and another (SN: 1754) from Ciné Matériél in Paris.

 
 

Lens Turrent

 
Some machines in Austria have been equipped with lens turrents

DP70s in Austria

 
 

The Align-O-Tron

 
laser2.jpg - 29710 BytesHow to align your lamp house with the Align-O-Tron by Greg Müller
 
 

DP70 special digital reader bracket

 
DP70 special reader bracket for mounting digital sound heads. Seen here are the DTS and Dolby readers.

 
 

Cinefocus (no longer available)

 
The Century Cinefocus system applied just slightly positive air pressure to the film from an outboard blower to keep it from rapidly fluttering when the heat from large arc lamps would hit the film.

Obsolete technology. See more

 
 

Photo mask by Todd-AO
To boost the high end output to 0dB at 12.5K and -1dB at 16K. (No longer available)

 
Newly developed photographic slit masks for the DP70 optical sound head enable the DP70 to faithfully reproduce audio up to 12.5 kHz at 0dB with little slit loss compensation added in the pre-amplifier stage. This is equivalent to a half-mil slit or less in a forward scan sound head. 

The original brass slits were expensive to manufacture; it was difficult to obtain clean and straight edges on the sides of the slit, so they were limited in their high-frequency output. Not only do the new photo slits capture the high-end frequencies of modern stereo optical sound tracks, they are inexpensive and easy to install.

Photo mask by Todd-AO to boost the high end output to 0dB at 12.5K and -1dB at 16K.
 
 

A new film gate for the DP70 projector

 
Rosbeek Techniek in Holland have made a new 35mm film gate for the DP70. This will also be available for 70mm. It is made of black Delrin. The old one is a little flat at the gate because the film should run as flat as possible through the gate. The lenses back than were not so good as the lenses these days to perform under a little difficult situation what the flat part of the film gate is because the film can hardly run flat over a most bended film gate.

A new film gate for the DP70 projector
 
 
 
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Updated 28-07-24