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Discussion Starter · #1 ·
The Sharp Z7000 has a 150 watt UHP bulb, 800*600 res, and generates 1000 lumens ( http://www.projectorcentral.com/projector_details.cfm?part_id=1149 ).


The Sharp Z9000 has a 250 watt NSH bulb, 1280*720 pixels, and generates 800 lumens ( http://www.avsforum.com/ubb/Forum10/HTML/007972.html ).


The new bulb uses 60% more power but yields 20% less light. Either the higher resolution increases the black fill to pixel ratio, watts don't equal lumens, the Z7000 has a white segment, or the new color wheels have more "dead space" during which light can't be transmitted. Anyone know which it is?


I had pinned my hopes on the new DLPs being good enough to buy (16*9, bright enough for a real room, and no rainbows).


Curses, now I'm back to considering the PLV-60 with the hope of getting lucky regarding dead pixels...
 

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Here are some more data points.


The Sanyo PLV-60 has has a 250 watt NSH bulb (same as the Z9000), 1366*768 pixels, and generates 1200 lumens. A few more pixels and 50% more light (obviously three panels are more efficient than a spinning wheel).


The Sanyo XP-21 has has a 200 watt UHP bulb, 1024*768 pixels, and generates 2500 lumens. Holy cow that's efficient! I wonder how they do it?


So what about lumens/pixel on the screen?


Z7000 = 1000/800*600 = .0020

Z9000 = 800/1280*720 = .0009

PLV-60 = 1200/1366*768 = .0011

XP-21 = 2500/1024*768 = .0032


I probably should be calculating lumens/square inch but the figures are interesting none-the-less...
 

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Quote:
Originally posted by Red Brian:
The new bulb uses 60% more power but yields 20% less light. Either the higher resolution increases the black fill to pixel ratio, watts don't equal lumens, the Z7000 has a white segment, or the new color wheels have more "dead space" during which light can't be transmitted. Anyone know which it is?
My guess would be all of the above.


Increased pixel structure (over 90% more pixels in this case) does seem to decrease light output (look at projectors that offer svga and xga versions on the same chassis).


And increasing the wattage by 60% would lead to a less than 60% increase in lumens (assuming its essentially the same technology).


Plus the fact that it is a 16:9 chip might also lead to an addition loss in efficiency.


Be interesting to see what sort of bulb would be needed for hdtv resolution chip (but honey, not only can we watch hdtv on a big screen, we can heat the house at the same time http://www.avsforum.com/ubb/smile.gif )


Todd (who is an expert at none of this!)
 

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The lack of a clear section accounts for a lot of the decrease. Instead of passing unfiltered white light to boost the lumen ratings, they are now filtering all the light so you lose some brightness. Also, being a home theatre projector they may be a little more "conservative" with their lumens rating. I think the point on 16*9 chips probably also has something to do with it, they have to focus the light onto a wider spot than for a 4:3, which is probably harder to do.


Also, regarding the XP21, I believe the panels have MLA (micro lenses) which gives a pretty big boost to efficiency.


Regards,


Kam Fung
 
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