Film-Tech Forum ARCHIVE: Odd effect as projector starts up

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Posted by Thomas Pitt (Member # 4322) on 09-01-2008, 03:29 PM:

I went to see Babylon AD in a different cinema to the one I usually go to, and saw something strange as the projector started up. It looked like multiple 'diamonds' of light, a bit like what you get when shining a light through a cut gemstone. This happened after the projectionist hit start, but before the first image hit the screen - i.e. only for a split second.

Anyone have any idea what caused this? Whatever it was, it didn't interfere with the movie itself. The projector was badly out of alignment and had no flat aperture plate for the adverts/trailers, but that's another story. [Wink]

Posted by Frank Angel (Member # 248) on 09-01-2008, 04:36 PM:

Are you sure it was from the projector? Could it have been a reflection off something else and only a coincidence that it happened when the projector started? Of if it was from the projector or booth, it might be something very simple like the glass door on the projector reflecting lamphouse light just as he closed it.

We discovered something similar where if a car drove by at a certain time in the afternoon, sunlight would be reflected off some metal or glass on the car and a very small speck of light would seep thru a door crack and move across part of the screen.

Just a thought.

Posted by Hugh McCullough (Member # 1542) on 09-01-2008, 05:31 PM:

This could be a digital projector fault.
It used to happen on our NEC 800C projector about every ten or twelve shows.
We got a very slight flash of the three primary colours just before the dowser opened.
It did not seem to matter if you placed black before or after the dowser opening.
As it was an intermittent fault, and would not manifest itself when the engineer was present, it was decided to leave it, and after a few months it appeared to have cured itself, we hope.

Posted by Thomas Pitt (Member # 4322) on 09-01-2008, 06:14 PM:

I doubt it was a digital projector issue; this cinema doesn't even HAVE a digital projector [Razz]

It was a Simplex Millennium with Christie lamphouse, I think.

I think Frank's theory about the glass door reflecting light seems the most probable. It's a multiplex, and there are no windows to the outside in the booth as far as I can see. It could well have been the 'strips' of light from a lamphouse vent, being distorted and focused by the glass door, and reflecting onto the screen briefly.

[ 09-02-2008, 11:43 AM: Message edited by: Thomas Pitt ]

Posted by Louis Bornwasser (Member # 3063) on 09-01-2008, 09:12 PM:

What projector? Some light MAY reflect just before the changeover opens (Simplex) Louis

Posted by Monte L Fullmer (Member # 2797) on 09-01-2008, 11:58 PM:

deleted

Posted by Demetris Thoupis (Member # 833) on 09-02-2008, 04:20 AM:

Perhaps it was a Kinoton E series projector. What the Kinoton do they ramp the speed up and then intermittent sprocket engages standard maltese movement.
Demetris

Posted by Michael Brown (Member # 890) on 09-02-2008, 07:39 PM:

Out of interest, which cinema was this at?

Posted by Thomas Pitt (Member # 4322) on 09-04-2008, 03:45 PM:

It was the Sheffield VUE (Meadowhall), screen 11 - one of their largest auditoriums. AFAIK all screens there use Simplex Millennium projectors with Christie lamphouses.

Posted by Monte L Fullmer (Member # 2797) on 09-04-2008, 06:33 PM:

Did that Christie burn a pinhole through the dowser plate - which is common for a Simplex since their dowser plates arent that all grand and when you got a big lamp behind it?

Another common fality with these things is that you get light leak around the dowser (being shaft pulled) if the dowser isn't sitting down all the way on it's stop block.

Posted by Elizabeth Betty Gross (Member # 2532) on 09-26-2008, 01:01 PM:

I noticed "dots" in a diamond pattern on a print just yesterday, which lasted for maybe one frame. Is it possible we were seeing encoded information added by the distributer to trace street copies?

Posted by Tony Bandiera Jr (Member # 2365) on 09-26-2008, 01:47 PM:

quote: Elizabeth Betty Gross
I noticed "dots" in a diamond pattern on a print just yesterday, which lasted for maybe one frame. Is it possible we were seeing encoded information added by the distributer to trace street copies?

Yes indeed, you noticed the dreaded "CRAP" code, used by the MPAA and studios to supposedly stop piracy.

A search of CRAP code or CAP Code (it's real name) on here will show a number of threads and posts.

Posted by Michael Brown (Member # 890) on 09-26-2008, 03:35 PM:

quote: Thomas Pitt
and saw something strange as the projector started up. It looked like multiple 'diamonds' of light, a bit like what you get when shining a light through a cut gemstone. This happened after the projectionist hit start, but before the first image hit the screen...

Could this be something as simple as the turret being open and the projectionist happened to be by the machine as it started and closed the turret when they realised it was open.

Posted by Marco Giustini (Member # 4544) on 09-26-2008, 07:27 PM:

Vue bought from Warner Village in UK and Warner Village uses Cinemeccanica V5 and V8.

Some "shine of light" is seen if some light spills from the lamphouse during lens change.

I had something similar when, with my V5, I forgot to replace a screw on the projector's cone. The light was coming out from the screw's hole and display a slight and curious effect on the screen at lens' change, but just slightly and just for a moment.
A friend of mine called it "Blades of light"! [Smile]

Marco

Posted by System Notices (Member # 2357) on 04-27-2010, 09:22 PM:

It has been 578 days since the last post.

Posted by Michael Brown (Member # 890) on 04-27-2010, 09:22 PM:

I was at the sheffield site (just to catch a few films on a day off) on monday, there seemed to be several curious things going on. Most curiousthat they seem to run widescreen advets and trailers with a scope plate in the projector, so you are treated to extra image being projected above and below the screen, (with image hitting the ceiling and image being projected onto the back of the seats in the front row. Seen this about 3 or 4 times now, all in differnt screens.

Posted by Caleb Johnstone-Cowan (Member # 3710) on 04-29-2010, 08:30 PM:

That's truly bizarre, did you ask a staff member/manager why?