Do projector lamps dim with age?

The_Munter

Standard Member
I have a panny AE700 - had it for about 3 years. I THINK that the lamp is starting to dim but I also think I maybe imagining it. It's done about 500 hrs.


So my question is: do they dim with age?:lease:
 

sbowler

Well-known Member
I like you have the panny mines coming upto 480hrs, cant say I have noticed a difference yet. They do say it does dim from around 500hrs though. Nothing to worry about as I find it quite bright. How much dimmer is it? if you can describe.
 

Peter Parker

Distinguished Member
All current projector lamps dim with age to some degree. You generally don't notice it since it's a gradual process and you're eyes are very adaptive anyway. Without a reference you won't realise the image has dimmed until it has done so by quite a bit. You don't see luminance in a linear fashion, and you perceive a 50% drop when it has actually reduced by 82%.

You can measure the drop in luminance with a light meter if you were that curious, and if you did it at regular intervals you'd be able to plot a graph.

Gary
 

The_Munter

Standard Member
Thanks. I'm not sure if it has dimmed or I'm just fed up with the black levels. I may get myself one of those JVC HD1s hmmmmm...
 

Alhambra

Standard Member
500 hours in 3 years? :eek: I've done 2000 hours in 1.5 years on my AE900 :rotfl: and I hope to crank out another 1000. To be honest it doesn't seem a hell of a lot dimmer. I probably wont notice the difference until I replace the bulb.
 

DaveWolf

Active Member
I've done ~1200 hours in 18 months on my AE900 - but I did notice it "flickering" recently, so I upped the lamp power to HIGH and its gone away :) ; But its noisier now, which is a shame :-(

Does that sound right?
 

Peter Parker

Distinguished Member
Lamp flicker sometimes means the arc is just moving from one point to another on the anode/cathode, and putting it on high lamp can alleviate it. You may find that after the arc has bedded in again you can go back to low mode without the flicker.

Gary
 

Apone

Well-known Member
My thoughts on this issue are that the bigger the screen the greater the chance of you noticing the lamp becoming dimmer with age/usage etc

Eg the same pj is on a 6ft screen compared to another screen size of 8ft. Assuming usage stats etc are the same then any lamp dimming would be more pronounced on the larger screen.

Just my 2 pence worth
 

DaveWolf

Active Member
Lamp flicker sometimes means the arc is just moving from one point to another on the anode/cathode, and putting it on high lamp can alleviate it. You may find that after the arc has bedded in again you can go back to low mode without the flicker.

Gary

Don't quite understand this "arc" business (Raiders of the Lost...?), but I've de-upped the lamp power back to LOW now (after running on HIGH power for a week or so (mainly playing Bioshock on the 360!) and the LOW power didn't flicker for me at all last night. :)

Ta all.
 

Peter Parker

Distinguished Member
UHP lamps are arc lamps rather than filament lamps like we have in our light bulbs at home, so the current has to arc across two electrodes to produce light rather than heat up a filament. Usually the point of least resistance means there is one arc point on each electrode, but sometimes as the arc point wears, another area on the electrode can offer similar resistance so the arc jumps across to there, and then back again, so you get flicker. Putting the lamp on high allows more current to flow and that can make one arc point more conductive (whichever offers least resistance to conductivity) so the lamp flicker goes. As the arc burns in that electrode, the new arc point becomes the point of least resistance so going back to low means the same arc points remain in use.

Hope that makes sense :)

Gary.
 

DaveWolf

Active Member
Wow - it is still possible to learn something new everyday!! I'll try to introduce that fact into the next drunken pub argument I am involved in! :thumbsup:
 

AV Nik

Active Member
There are differences between certain lamps. Some lamps ARC between anode and cathode poles permanently like flash lights and strobe type lamps and others ARC for a moment and then regulate a voltage to keep a gas reaction going which is predominantly what you see in High Pressure Discharge lamps and Xenon/Metal Halide within projectors.
Near enough every lamp including the tiny LED lamps will have a gas of sorts to either create the light output or to regulate voltage. Some gass's are used just to pressurise part or all of the lamp.

Most projector lamps dim as the gas deminishes over time due to use. As most video projector lamps are high pressure discharge lamps, the gas is also used for pressure which is one reason why they implode/explode when used for too long. this is why we have lamp timers and warning lights on the modern projectors.

Hope this helps.

AV Nik.. Once a Lampy !!!
 

Spooksta

Well-known Member
Im on 2300hrs on my AE700 and also had the flickering problem. High power for a few days sorted it each time and then back to low.
btw
Just got a spare bulb for £124 delivered from Japan. and it came in under a week.
 

GavT

Member
UHP lamps are arc lamps rather than filament lamps like we have in our light bulbs at home, so the current has to arc across two electrodes to produce light rather than heat up a filament. Usually the point of least resistance means there is one arc point on each electrode, but sometimes as the arc point wears, another area on the electrode can offer similar resistance so the arc jumps across to there, and then back again, so you get flicker. Putting the lamp on high allows more current to flow and that can make one arc point more conductive (whichever offers least resistance to conductivity) so the lamp flicker goes. As the arc burns in that electrode, the new arc point becomes the point of least resistance so going back to low means the same arc points remain in use.

Hope that makes sense :)

Gary.

Great advice. Had flickering on my AE200, thought the lamp was a goner but 1 film on high power sorted it out.

You gotta love AVForums for the sound and trustworthy advice ;)
 
I

iforgot

Guest
Im on my orginal z2 bulb 3600 hours in, just waiting for it to go, i had flicker a while back, but noticed that some daytime watching on full sorted it out.

As for brightness, i would definity say the lamp has definitly dimmed compared to new, but then again im 600ish hours over the quoted lifetime of the bulb. However as people have said its a slow process and you dont notice it.. just the same way you dont notice kids grow when you see them everyday, but relatives away for a while notice it.
 

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