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I went scanning thru the RPTV forum looking at discussion around bulb life and failures to see what's happening. It looks like some owners have similar problems with "premature rejeculation"...:) like some FP owners. However, one thing that I noticed was that sets were quoting " 4000 hours....8000 hours.... 10000 hours...etc". I was wondering why RPTV units are "seeing" these kind of numbers versus the "1000, 2000, 4000" hours that FP are seeing? Are the engines and bulbs that much different? Is the cooling / environment that much better? Originally, I was "cruising" thru the RPTV group to see whether their fan units stay on all the time even when the set is turned off.... it appears so (although I didn't see that specifically stated).


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Budwich, I wondered about this too -- somewhere "aloud" in the forum. Some felt cooling was key and I suppose that is plausible, although it suggests that we might want to all find ways to cool our front projectors, too.


I can't imagine the engines being appreciably different in a way that would improve life other than cooling.


The fans staying on all the time -- like when the TV is not operating -- shouldn't really matter much. But perhaps getting the heat away from the lamp a lot more efficiently using the extra box space and a larger volume fan makes a huge difference?


Mark
 

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wouldn't the brightness of the bulb be somewhat lower also considering the small screensize and probable screen gain coupled with the fact that it will only be spitting out around 30 f/l anyway?


you'd have to imagine that only around 250 lumens would be necessary in most instances, no?
 

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The primary difference appears the be the output.


For RP you don't need the same lumens to generate an equally bright pricture (ft. lamberts) because the image size is typically smaller (assuming equal gain screens).


Lets assume that the X1 (1100) lumens is projecting on an 80"x45" screen is about 44 ft lamberts (1 gain screen). The 50"x28" wide Samsung at 50 ft lamberts requires around 487 lumens...if my math is correct.


Typically econo-mode (lower lumens) increases bulb life...so if the Samsung is running at about half the lumens of a 4000 hour projector a 8000-10000 life seems about right even assuming the relationship isn't entirely linear.


I wouldn't expect the cooling to be the primary factor except as a function that a lower output bulb generates less heat.


Nigel
 

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Quote:
Originally posted by gbrnole
wouldn't the brightness of the bulb be somewhat lower also considering the small screensize and probable screen gain coupled with the fact that it will only be spitting out around 30 f/l anyway?


you'd have to imagine that only around 250 lumens would be necessary in most instances, no?
Heh, what he said. I was flipping around the net looking up SMPTE specs (TV). I think its in the 50 f/l range.


As an aside, I discovered that double stacking projectors does produce twice the lumens.


Nigel
 
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