# Epson 8500 UB magenta -patches



## stev (Aug 7, 2010)

This is exactly my woe:-
Slight pink-magenta cast in the middle brightness range and a slight unevenness in the white field, with subtle additional magenta tinges in various areas of the image, unnoticeable on color material, though they are visible if you look for them very carefully . I tried different sources with HDMI and YCBCR. The result is the same. Different color modes like the HDMI wide and YCBCR 4-2-2, YCBCR 4.4.4, RGB and the auto modes were used to configure, but with same results.

What this could be due to?
I use a sony blu ray player, the BDP S 370 with an HDMI in-out and that's it. No loose ends anywhere. Power line stable.
The test signal used to check the whites was from the 'LIFE' series blu ray from BBC where it carries a HI DEF set up as an extra. The whites had the magenta at about three points, all of them in varying intensty, but is evident only on close scrutiny. With this information in mind when you go to watch any programme material you can identify the magenta there. But for someone who hasn't seen the white test this magenta may escape him.
Can you kindly throw some light please?
The projector is just 100 lamp hours old.


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## Michael Osadciw (Apr 4, 2009)

have you ever tried setting the grayscale or gamma controls and just left them? it's possible you've taken green out of the image?

if you have a disc of test patterns, put up a grayscale step pattern and see what part of the image it affects. you can then possibly zero in on that area of the image and make changes.

What picture mode are you viewing it in?

There will always be uneveness with the white field on this projector. it's the nature of this unit...and it's 3-LCD red green blue... you'll see a colour temperature shift from one side to the other. ...no way to get rid of this...seen mostly in the skies...


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## stev (Aug 7, 2010)

Michael Osadciw said:


> have you ever tried setting the grayscale or gamma controls and just left them? it's possible you've taken green out of the image?
> 
> if you have a disc of test patterns, put up a grayscale step pattern and see what part of the image it affects. you can then possibly zero in on that area of the image and make changes.
> 
> ...


thanks for the reply. i am using theatre black 1 and on the eco mode. the problem is, with the color scale tests, it is impossible to trace the patch. with the gray scale it is evident on the zone 6-7 area, if we take it as a scale of 10 , black to white. 
Yes, i have tried all the possible permutations possible with the RGB/YMC, Gamma and with the gain controls of the red and magenta. i first used the default 18% grayscale color temp of 6500K went upto 7000 now with no better results that are noticable than it was earlier. tint and gamma combo also did not yield much difference but interfered with the other factors in general. if i would mend with it anymore, the flesh tones are likely to suffer. now except for this hue at a certain point, the rest of the picture looks awesomely good.
i was wondering if this had anything to do with an individual production problem from a batch or bad quality control. the fact is, even though this such a glaring glitch, no reviewer yet had mentioned it either at the calibration level or conclusion. 
i appreciate the time you took to reply and would be grateful if any of the forum members can throw more light in the respect as and when it occurs to them.


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## lsiberian (Mar 24, 2009)

That sounds strange. Could it be something with one your screen. Try it against the wall and see if it still shows up. If it does you may want to contact Epson and get it serviced. Something could have gotten damaged to cause the color issue.


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## stev (Aug 7, 2010)

lsiberian said:


> That sounds strange. Could it be something with one your screen. Try it against the wall and see if it still shows up. If it does you may want to contact Epson and get it serviced. Something could have gotten damaged to cause the color issue.


thanks for the reply.

No it isn't the screen. i've checked that too.


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