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Discussion Starter #1
I have a panny 300. Initially I was very impressed with the picture(and I still am after 1000hrs) but I realized that during bright seens the entire image was washed out(black areas lit up quite a bit). So I decided to black felt the entire room. WoW it was a great difference, no light reflected fromt the screen to the walls back to the screen anymore.


I am still noticing though that it seems to light up dark areas(not nearly as much as before but still a good amount). TO make sure the light was not being reflected off anything in the room back onto the screen I took the projector off the ceiling mount and found a bright seen to puase on the dvd player. I pointed the projector so that the entire image was in the black felt. I looked at the screen and it was fairly lit up. I was kinda surprised at first but then this makes sense as there will always be some light spill from the projector lense itself, light that is not focused at all but just spread out coming out of the lens. Also makes sense since you can tell the the projector is on by looking at the lense without being in the direct path from the lens to the screen(you can see light off the lens)


So if this is inherrant to any projector(LCD, DLP, Slide) other than CRT(not really sure bout these) how can DLP provide that much better contrast druing brighter seens(or dont they?) It seems that the optics are the downfall of contrast, not the chip(lcd,dlp), in certain cases. When I shined the projector at the felt only, it lit up the screen a lot more than when the projector projects an all "black" image directly at the screen.


Dan
 

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Apparently, LCD panels just don't block light as well as DLP mirrors divert it. The better contrast ratio for DLP projectors is, so far as I can tell, entirely due to this phenomenon. Of course, optics aren't perfect either, but I think they tend to be equivalent between the two types of projectors.
 

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Quote:
Originally posted by danjros
So if this is inherrant to any projector(LCD, DLP, Slide) other than CRT(not really sure bout these) how can DLP provide that much better contrast druing brighter seens(or dont they?)
What you are describing is best shown by ANSI contrast ratio. That test is with a checkerboard of alternating black and white squares and is basically the ratio between the bright squares and the dark squares. DLPs actually look to be the best in this test by far. A very good CRT might be at 320:1 while my Sharp 11k looks to be over 700:1 (my room might have been my limiting factor) in high contrast mode and over 500:1 in high brightness mode (different iris settings). I don't know what kind of numbers you would get from an LCD, but I don't think they are close to single chip DLPs in this test and your results would seem to also indicate that. Maybe I'll measure this on my AE500 at some point here.


--Darin
 

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Discussion Starter #4
yeah i dont know... i was just thinking about it and it was late and i was bored so i posted on here. I still love my projector but I just wanted to see what others think. I was just amazed how much light leaked straight from the lense to other parts of the room. Just cupping my hands around the lens I could see how much light leaked out. I guess thats why the newer projectors have a iris feature. Whatever...I just need to stop trying to get everything perfect and enjoy the movies/shows I watch. Thanks for the input though.


Dan
 
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