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Discussion Starter · #1 ·
I am seeing mosquito noise from 9 ft away on a 79" diagonal widescreen image. This is the dithering effect, not DVD noise. It is apparent on all dark scenes, on all movies. I know people say if you get within a foot or two of your screen then mosquito noise is visible, but this is 9 ft away!


This is occuring in video mode with my contrast at -12. Adjusting brightness doesn't help at all. In fact the lower I set the brightness, the worse it gets.


Any suggestions?
 

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Use Avia to calibrate the PJ, though that still won't completely eliminate it, it will help. The BenQ has a tendency to crush whites and blacks, as well as introduce excessive mosquito noise if not properly calibrated.


Having said that, I can see mosquito noise from 10' back with my 96" diagonal screen. That's just the price you pay for a cheap projector.


Russell
 

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I get mosquito noise as well on my PB6100, particularly on bright skies, where the noise shows up in the white clouds. I found that if I went into the service menu and turned the white segment down (I can't remember the name of the menu item, it's a 1-10 scale and is set at 0 for theater mode and 10 for econo mode with a VGA input) it basically eliminated the noise.


Unfortunately, the BenQ won't save changes to this setting, so if you shut off the projector or even change the input, it cranks the value back up to 10.


One other thought: I believe that while the value is set to 10 for VGA inputs, it's set to 4 for component inputs. If you're using an HTPC with a VGA input, it's possible that switching to some sort of component input device might minimize the noise by virtue of the lower setting. I haven't tried this myself, but it may be worth a shot.

Edit: I just noticed that your problem shows up in dark scenes as well, so it may not be helped by my suggestions after all.
 

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Machismo,


Have you ever gone into the service menu? I had a similar issue that was caused by me changing a couple settings.


-Angryht
 

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Machismo,


Yes, going into the service menu to change the gamma values will change the response curves for black and should minimize it, the trick is to restrict the the mosquito noise to specific grey levels.


Most importantly, you have to set the black level (ex. the large background for THX pattern ) to black with no mosquito noise at all. Most dark scenes use this black level for the majority of the image, if you ensure that it is free from mosquito noise, you then have almost got rid of it entirely.


Another way to get rid of mosquito noise is to use an ND filter or CCR filter.

Neutral density filters (not too dark, nd2) will easily work without re-calibrating the color settings. A CCR filter will require to make some color corrections, but this could ultimately improve contrast levels.


-Bob
 

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Could this be a cable or signal quality issue? I had mosquito noise when I first go my projector and was using a cheap after market XBox component breakout box. After reading this forum, someone told me to get the Microsoft component breakout box and mosquito noise (among other artifacts) where totally gone. My DVD is HTPC running via VGA and I never had this issue.
 

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I adjusted the DLP Contrast/Brightness and Peak in the Service Menu, along with that and calibrating with DVD, I hardly see the "mosquitoes" or "sparklies" anymore. Uncalibrated however and messing around with the standard menu can produce some bad ones..
 

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Discussion Starter · #8 ·
Thanks a whole bunch for the replies guys.


Well I calibrated with Avia in video mode (i stopped using economic mode because the whites were terrible), I arbitrarily went with a contrast of -12, because that was around 25-30% of the total contrast level. Is there a better way to do this? I do not see any type of blooming when adjusting contrast levels in the Avia test pattern. I think this is due to me using a DLP projector. For some reason, I have to set my brightness level way above zero to pass the Avia test pattern.


As far as the cables go, I am using a pretty good quality VGA cable from my PC to the projector. It is shielded pretty well and I receive no ghosting.


Man, I would love to do some adjustments to the service menu, but it would be a pain to have to set these values over and over again, due to not being able to save settings in the service menu.


I seem to have restricted most the noise to certain shades of black, but I was hoping to remove the mosquito noise completely from my viewing distance.


bob619, I will try to further restrict the noise like you said, but doing this from the service menu doesn't seem like a viable option for me. By the way, what is a ND filter or CCR filter actually? Is it a lens filter?


From your comments I am gathering that seeing mosquito noise is rather common, even at these further distances?
 

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Yeah mine had terrible noise in the whites as well using VGA, on economic and presentation mode. somehow it is a perfect picture on video mode (for noise) but the colors were funny so a little hue adjust on dvd player makes it look real nice. Its just too bad I can't get the 3000 hours out of the bulb on video mode.


Some people don't get the noisy whites in eco mode I see, I think this is because that white Peak value is different for the various inputs (VGA is maxed out at 10) and they are probably using component inputs, so I might pick up the ati component dongle if thats the case to get a nice eco mode.


I also read in another post that turning down both the dlp brightness and contrast in service menu has same effect as turning down that white peak value, and these changes don't get reset when you power down the unit (white peak level value does), this must be what you did Swat? I will try that next before using component inputs.


Kille
 
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