Film-Tech Forum ARCHIVE: ? bulb practices ? power down or douser ?

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Posted by Drew King (Member # 6349) on 06-21-2011, 05:48 PM:

I am operating a NEC NC 1200C DLP cinema projector.

My inquiry regards bulb usage.

We are using the projector for 3D dailies. Typically the projector will be used for a 45 min session. Then a 2 hour down period and will be used again for another 30-45min. Should I power down and re power the bulb for those two hours of down time? or should I just close the douser and keep the bulb on.

From what I understand there is a strain put onto the bulb every time it is powered up/down that could be greater than just keeping it powered on.

Any advice would be greatly appreciated. Thank you.

Posted by Monte L Fullmer (Member # 2797) on 06-21-2011, 05:59 PM:

I'd power it down since you have such a good length of down time between viewings.

Your downtime is longer (almost twice as long) than operating time, thus it's more feasible for power down.

If you were down between viewings for a half hour or less, then I'd leave the bulb on with douser closed.

... - Monte

Posted by Kurt Zupin (Member # 2751) on 06-21-2011, 06:35 PM:

We have the same NEC and the lamp stays on all Day. Granted we only have an hour of down time between shows. Leaving it on isn't really going to hurt it, its really up to you. The real issue with the NEC is the sheer time it takes to power cycle the stupid thing. When you have two hours between usage its not that big a deal though.

Posted by Carsten Kurz (Member # 5396) on 06-21-2011, 09:07 PM:

I recently talked to an Ushio representative. He told me that Ushio did actual testing on xenon bulb cycling. They came to the conclusion that they can/should be powered down when the pause exceeds 10-15minutes.

Given the price of these bulbs, I find it hard to believe that someone has them running all day long.

Now, Ushio was only talking about bulbs - whereas a projector contains more than just the bulb.
And some people simply think that letting equipment run continously is always better than switching off. Personally, I wouldn't do it.

- Carsten

Posted by Kurt Zupin (Member # 2751) on 06-21-2011, 09:32 PM:

I agree on powering it down, however the NEC is a a giant Piece. The power down power up cycle takes over 5 minutes both ways. Its not as simple as just turning off the lamp. We have a Christi and the lamp on that comes on at the start and off at the end.

Posted by Steve Guttag (Member # 268) on 06-21-2011, 10:28 PM:

In any respect...I would NOT close the douser...what purpose would it solve (unless the douser is right where the light exits the lamphouse area).

My opinion on the matter based on your use cycle is to power down the lamp

Note, there is a setting in the DCC software to allow the projector to restrike the lamp while it is cooling. As such, it should not take any more time than another projector to just restrike the lamp.

-Steve

Posted by Drew King (Member # 6349) on 06-23-2011, 05:23 PM:

Thank you very much!