Film-Tech Forum ARCHIVE: Digital Steadiness

This is topic Digital Steadiness in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=000078

Posted by Antonio Marcheselli (Member # 373) on 01-15-2002, 02:15 PM:

In Italy Multiplex Arcadia is the first theater equipped with a D-Cinema projector. It is a Barco on a Cinemeccanica consolle.
I dind't see the movie (Atlantis) but a friend of mine told me that after the movie he was under the screen where he saw the "pixels". He told me that those pixels was not staedy and that they was moving of about 2/3 centimeters.
How is it possibile? The cooling system?

Bye
Antonio

Posted by John Pytlak (Member # 331) on 01-15-2002, 02:55 PM:

Antonio said: "He told me that those pixels was not staedy and that they was moving of about 2/3 centimeters.
How is it possibile? The cooling system?"

I suspect there was some vibration in the projector or optics. Those are very massive lenses hanging in front of the projector, and there are cooling fans and coolant recirculators. You still need to pay attention to the basics of projection for "Digital Done Right", just as you do for "Film Done Right".

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Antonio Marcheselli (Member # 373) on 01-16-2002, 04:34 AM:

Thanks John

Antonio

Posted by Ben Stephenson (Member # 741) on 01-25-2002, 04:43 PM:

We have a DLP and did have Alantis and now have Monsters Inc and had no problems at all. The image is very very good. But Alantis was a digital copy of a 35mm print.

Posted by John Pytlak (Member # 331) on 01-25-2002, 06:02 PM:

Antonio said the pixels themselves were unsteady, which would likely be caused by projector vibration.

Posted by Antonio Marcheselli (Member # 373) on 01-26-2002, 07:29 AM:

John

I didn't saw the movie, it is projected in a 600km far theater...

A friend of mine saw it and was unable to tell me if pixels were moving or just the image.

Bye
Antonio

Posted by Richard Fowler (Member # 893) on 01-26-2002, 09:48 AM:

The Barco D-Cine on a Cinemeccanica console should not vibrate if the tilt bolts and projector hanger mount are tight. Cinemeccanica consoles put the power supply on the floor support so it can not add to the mass to help dampen the weight of the very heavy & large anamorphics used for presentation.............
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com

Posted by Ben Stephenson (Member # 741) on 01-26-2002, 09:56 AM:

No moving parts on a DLP to cause image shake (well cooling fan and some other small moving parts) sounds like an internal falt, When we get DLP films the image is checked before the engineer leaves..i would have thought that this would be the same with all DLP instalations

Posted by Owen Shave (Member # 1156) on 02-17-2002, 07:44 PM:

yeah... I watched Atlantis in DLP at our gaff, Ben and it was definately below par compared to the other DLP films we've had. Two thumbs up for DLP on the largest screen in Europe (just in time for episode II please

)
the screen is 21.24m by 9.04m... how does this compare internationally? our IMAX screen is only 5 metres wider.. but of course its twice as tall. Big is not necessarily beautiful.. focus is often slightly soft with films on this screen.

Posted by Mark Gulbrandsen (Member # 72) on 02-17-2002, 07:47 PM:

Larry Shaw are you out there????
If I remember correctly film has won out over D-cinema for steadiness every year at Showest. Can you verify this, or please, shoot me down.
Mark @ Home

Posted by John Pytlak (Member # 331) on 02-18-2002, 01:28 PM:

Unsteadiness is usually NOT one of Digital Cinema's problems (except possibly due to any vibration of the equipment or optics).

Unsteadiness is NOT a problem with "Film Done Right" either. SMPTE Recommended Practice RP 105 specifies less than 0.12% "jump" and 0.20% "weave" for 35mm projection on "large appearing" screens. Proper lab procedures (i.e., always contact printing short pitch originals to long pitch raw stock, and using a pin-registered printer if you can't) and well-maintained projectors can achieve this level of steadiness.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 585-477-5325 Cell: 716-781-4036 Fax: 585-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion