View Full Version : In need of expert opinion
ddlooping
14-07-2007, 6:42 PM
Hello everybody. :)
I need some expert opinion on the following issue:
I have burned the two attached images to CD and played them via my Xbox 360 (component output) on my newly acquired Sharp LC37RD2E LCD TV.
After tweaking the brightness, contrast and backlight settings the "grey_scale.jpg" appears more or less as it should.
I can fairly easily differentiate between all the bars from my normal seating position (8 feet from screen / dead center).
However, most bars on the left side of "grey_scale3.jpg" merge into each others by group of 3-4 (bad gamma tracking?).
Some can only be seen at an angle, moving closer to the screen.
My question is: do you think/know if the service menu options on the LC37RD2E are good enough to correct or at least visibly improved this problem?
Thanks in advance. :smashin:
ddlooping
18-07-2007, 2:16 PM
Anyboby? :lease:
Hi,
I'll trie to help ddlooping.
What exactly is the problem here?, looks like you're using two different grayscale's to solve the problem, if there is any....
If you notice that the left bars of the grayscale merge, than trie to adjust this using the brightness setting on the panel, with which you control the detail in the dark areas.
The goal here is to get your blacks as deep as possible without losing detail.
Turn up the brightness excessively to see exactly where you should be abled to see differenciation between the bars, and then turn it down to the point where they just can be seen independantly.
Dimitri
ddlooping
19-07-2007, 8:46 PM
Thanks for the reply, Dimitri. :)
With the "grey_scale3.jpg" image the bars are merged even if I turn the brightness all the way up.
That's why I was wondering if the options in the service menu were precise enough to correct the gamma curve (?) in the low IRE (?).
(?): a term I might be using improperly but I hope will convey my meaning. ;)
Gordon @ Convergent AV
20-07-2007, 4:20 PM
Yes you are using the correct term. It appears that your display comes out of black to slowly or is just incapable of showing those small changes in brightness in the darkest parts of the image. I've not worked on one of these sets but I can say that I don't know of any other display that has the sort of gamma manipulation you may require.
Gordon
Hi,
Have you tried any other type of calibration software?, or displayed the jpegs on another display?. Just to see if that gives you the same results?.
Dimitri
ddlooping
20-07-2007, 6:16 PM
...I've not worked on one of these sets but I can say that I don't know of any other display that has the sort of gamma manipulation you may require.
Thanks Gordon.
Not good news but what I kind of expected.
Hi,
Have you tried ... displaying the jpegs on another display?
Dimitri
Yes Dimitri.
On both my two EIZO LCD monitors, all but the darkest two bars can be clearly seen, with no merging or dithering.
I created this image (grey_scale3.jpg) as I had noticed a lack of dynamic in the low IRE (!) during normal viewing.
I guess there is nothing I can do short of changing the set. :(
Is there another LCD tv of that size (or 40") that performs better in that area though?
Is there another LCD tv of that size (or 40") that performs better in that area though?
I'm pretty sure there is, but why don't you trie contacting sharp and tell them the problem?.
You never know...maybe firmware will do the trick.
Dimitri
Neil Davidson
22-07-2007, 10:34 AM
It seems to me that there is more than a chance that the levels have been screwed up somewhere between the PC and the player.
Why not download the Merifon DVD (search here for Merifon) and use the greyscale ramps on there to give a more deterministic analysis.
Neil
ddlooping
22-07-2007, 2:35 PM
..why don't you try contacting sharp and tell them the problem?
I'll give it a try, D65. I guess all I can lose is some of my time.
It seems to me that there is more than a chance that the levels have been screwed up somewhere between the PC and the player.
Why not download the Merifon DVD (search here for Merifon) and use the greyscale ramps on there to give a more deterministic analysis.
Neil
Thanks for the reply, ceenhad.
The image was created in Photoshop, adding "+2 +2 +2" on the RGB values for each band.
I've just realised I had made the black band twice as wide, hence my inability to differentiate between the first two bars on my EIZO monitors. :oops:
It was then burned to CD as uncompressed JPEG and then played on the Xbox 360 via component.
I don't think the levels could have been screwed during the whole procedure.
I'll give the Merifon DVD a try though, thanks for the suggestion. :)
ddlooping
22-07-2007, 8:11 PM
...I don't think the levels could have been screwed during the whole procedure....
Well, I couldn't have been more wrong.
I was using my Xbox 360 to conduct this particular test and just found out it does not pass "below-black". :oops:
Using my Panasonic S52 DVD player and Luis Merighi's "TestDVD (http://www.isaneri.it/bg/testDVD1_07.zip)", the Sharp is able to fully resolve all levels on the grey scales (from below-black to above-white).
Sorry to have wasted your time. :blush:
Gordon @ Convergent AV
23-07-2007, 8:02 AM
LOL: Well at least you got there in the end.
The bill is in the mail anyway...
Dimitri:hiya:
ddlooping
23-07-2007, 8:32 PM
The bill is in the mail anyway...
Dimitri:hiya:
:grin: