8mm Forum: Tip to help with Calculating Lamp Life

This is topic Tip to help with Calculating Lamp Life in forum 8mm Forum at 8mm Forum.

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Posted by Chip Gelmini (Member # 44) on January 11, 2006, 10:42 AM:

Hello

Last year I tried something new with my super 8 and now that a new year has started, what I tried worked very well.

Print out a 3 column, full page width spread sheet with about 40 lines using your spreadsheet program.

Label column A as TITLE

Label column B as FORMAT

label Column C as DATE

Each time you run a full length program; write down the basic information.

Benefits are plenty.

Analyze how many different shows were run by a siginificant time; break down between formats scope/flat/mono/stereo/opitcal/magnetic; and count up the total amount of screen time (hours) and predict your next bulb change.

This worked well for me, and I encourage others to give it a try.

Cheers,

CHIP G
January 11, 2006

Posted by Brad Miller (Member # 2) on January 11, 2006, 04:58 PM:

Good idea, but please change the topic title of this post as it is deceiving towards some kind of emergency. Thanks [Cool]

This brings up an interesting question, do most people here run a bulb until it dies, or do you guys take the bulb out once it hits a certain number of hours?

Posted by Kevin Faulkner (Member # 6) on January 11, 2006, 05:25 PM:

Until it dies unless it starts to get dull and patchy from discolouration. I take it Chip that this is based on an average 50hrs life?
Have changed the title for you. Brad is right it did sound a bit alarming [Eek!]

Kev.

Posted by Adrian Winchester (Member # 248) on January 11, 2006, 06:40 PM:

I run 200 or 250w lamps until they blow, but maybe not a 100w lamp in my Eumig, if it has seriously declined.

Posted by Winbert Hutahaean (Member # 58) on January 11, 2006, 07:08 PM:

I just happen to know that bulb's life is only 50 hours ..... [Confused]

So more money need to be invested now, hopefully my wife doesn't read this! [Big Grin]

So... I use Osram or Phillips EFR 100w 12 v..it is also 50 hours...??

Forgive me for that question.

cheers

Posted by Chip Gelmini (Member # 44) on January 11, 2006, 11:24 PM:

Hello

1) Sorry about the title guys, and thanks for changing it Kev. Regret that it may have sparked some wires....hehehe

2) I think this comes from my years as a projectionist and lamphouse maintenence....depending on the bulb (or theater manager) we rotated every 500 to 1,000 hours. And always opened the lamphouse for inspection every month although we did not always rotate everytime.

3) I change the bulbs when the reflector appears pitted and/or the bulb glass seems slightly dark. And yes, I am assuming 50 hours, Kev.

CG

Posted by Steve Klare (Member # 12) on January 12, 2006, 07:17 PM:

Useful information!, but can you introduce a derating factor for the vibration stresses caused by a 3 year old jumping around the projection area?

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