Adjusting your HD picture quality

yankov

SatelliteGuys Family
Original poster
Apr 14, 2004
51
0
I'm trying to improve quality of my HD picture.
I got 56' JVC AV-56WP74 Projection set and using DVI connection.
It seems to me that my HD channels are not as good as when I had HD channels from cable.
It looks like colors are slightly separated. It is more visible when there are small letters on the screen ( like on VOOM's main menu) or when they showing small moving objects ( such as remote shot of soccer players on channel 123). I tried to play with my sharpness / brightness setting, but nothing helps. I even ordered tune-up DVD on Amazon yesterday, but it will arrive in a week or so.
Any suggestions on how I can improve PQ for tomorrow's Sharks vs. Flames Stanley Cup game on ESPNHD ?
Thank you all for your advice.
 
yankov said:
It looks like colors are slightly separated. It is more visible when there are small letters on the screen ( like on VOOM's main menu) or when they showing small moving objects ( such as remote shot of soccer players on channel 123).

This sounds like your convergence is off. Your projection set has three "guns" of light that focus to make your picture: one red, one green, and one blue. When a projection set is moved or gets jostled, these guns become misaligned, and colors look "seperated". This also happens slowly over time. Check your owner's manual for your TV on how to adjust your convergence (sometimes called focus on some TVs) back to normal.
 
COuld be convergence. Have you always used your DVI connection? You may want to switch back to component connections and give that a try.

Also, over at the HomeTheaterSpot forum, you can find the Mits forum, and with a paid membership ($25), you can find specifics on how to tweak your particular model.

Lob
 
Try this

You mentioned a dvd disc you ordered. I hope it's Avia. I highly recommend that disc. It made a noticeable difference in my Mits.
Of course, the best way, is to have it ISF calibrated. It's expensive, but worth it.
Go to www.lionav.com to find out more.
 
Also, bear in mind that many TVs are adjusted on a per resolution or per input basis. So adjusting with a 480p DVD may not help you much on a 1080i input.

In your case it definantly sounds like convergance though. I am always tweaking mine. :p
 
Thank you for all replies, I was able to improve picture with manual convergence . Auto convergence did not help much, as right side of the screen was sharper then the left side regardless of the connection ( DVI or Component).
I wonder if plasma HD screens have this type of problems, or they unique to rear projection units?
 
reply

dledeaux said:
Also, bear in mind that many TVs are adjusted on a per resolution or per input basis. So adjusting with a 480p DVD may not help you much on a 1080i input.

In your case it definantly sounds like convergance though. I am always tweaking mine. :p
This is correct, especially with Mitsubishi. This is where having an ISF calibration comes into play.

I have started a thread on high performance cables. If you want to read it, go here.
www.satelliteguys.us/showthread.php?p=101983#post101983
 
yankov said:
Thank you for all replies, I was able to improve picture with manual convergence . Auto convergence did not help much, as right side of the screen was sharper then the left side regardless of the connection ( DVI or Component).
I wonder if plasma HD screens have this type of problems, or they unique to rear projection units?

Plasmas have no convergence problems at all (because there is nothing to converge). They also have no problems with geometrical distortions etc.
 
Iceman and others...how would I go about calibrating the DVI input if not just by your personal viewing preference? I am also getting AVIA for my Mits but this will only be good for my S-Video inputs, I don't have a component DVD player yet, but even if I did, it wouldn't help me fine tune the DVI input which is my Voom STB...

Am I off base here? Any ideas?
 
reply

truqui said:
Iceman and others...how would I go about calibrating the DVI input if not just by your personal viewing preference? I am also getting AVIA for my Mits but this will only be good for my S-Video inputs, I don't have a component DVD player yet, but even if I did, it wouldn't help me fine tune the DVI input which is my Voom STB...

Am I off base here? Any ideas?
Well.....I can only think of two.
1. Have your set ISFd. That will make your set deliver even better than its potential. How is that possible? By reprogramming the Eeprom, etc. This whole process of an ISF calibration takes about 4 hours, and it's gonna cost you some dough, but it's well worth it.

2. If voom has a input that upconverts to 1080i like the dish network 811 receiver, you can simply take the output from the dvd player (when you get one), to the input of the receiver. Then the receiver to the tv.

I wish I could be of more help.

Ice
 
Tru,

You are not off base at all. Typically an RPTV needs the signal type displayed for you to converge (or adjust in any way) that menu. So you need to be feeding it a 480i, 480p, 720p, or 1080i signal to adjust each input type. This is no problem for 480i and 480p signals as an Avia test DVD at either of these settings will work. But since virtually no DVD players and/or test media runs at 1080i, there isn't much of a way to support it.

THe best way to approach it is to set all your values through Avia (or Digital Video Essentials), write them down, then apply all the same values while watching 1080i content on the TV. They may not be perfect, but brightness, color, contrast, and so on should be in the same ballpark. Then perform a manual convergence by eye for the 1080i signal and you should have a pretty good looking picture.

Anyway, that's the quick and dirty way to do it. Definitely pick up a test DVD to learn about calibrating a system though, those things are great!

Best...
 
zot23 said:
Tru,

You are not off base at all. Typically an RPTV needs the signal type displayed for you to converge (or adjust in any way) that menu. So you need to be feeding it a 480i, 480p, 720p, or 1080i signal to adjust each input type. This is no problem for 480i and 480p signals as an Avia test DVD at either of these settings will work. But since virtually no DVD players and/or test media runs at 1080i, there isn't much of a way to support it.

THe best way to approach it is to set all your values through Avia (or Digital Video Essentials), write them down, then apply all the same values while watching 1080i content on the TV. They may not be perfect, but brightness, color, contrast, and so on should be in the same ballpark. Then perform a manual convergence by eye for the 1080i signal and you should have a pretty good looking picture.

Anyway, that's the quick and dirty way to do it. Definitely pick up a test DVD to learn about calibrating a system though, those things are great!

Best...

Hmm interesting...Thanks for the idea! And Iceman...I will look into ISF'ing in the future and when I get all the equipment I want....for now, my setup looks killer and I think I will try myself just to make it a tad better.

zot23...
So even if my DVD just has S-Video I could adjust it's input using AVIA, copy all the values and adjust the other inputs using the same values? So other than convergence, like you mentioned, they all should be tweaked alike...
Do you think I would be better off if I waited till I pick up a PS DVD player with at least component out?

Thanks again for the info...
 
Calibration tables on VOOM

Note, that HBO, Cinemax and some other channels on VOOM broadcast calibration tables from time to time. Most importantly, you can find a color calibration table, that works well with color filters included with DVE and other calibration disks. At least in theory, this should work better than color calibration through DVD. Not only you can use the correct input type and resolution mode, but you can correct/account for any color changes made by the STB itself and by any other equipment between the source and your TV set.

Look for "OFF AIR" or "SIGN OFF" sign in the program guide (except on Alt ESPN channels, which are OFF AIR all the time).
 
Ilya said:
Note, that HBO, Cinemax and some other channels on VOOM broadcast calibration tables from time to time. Most importantly, you can find a color calibration table, that works well with color filters included with DVE and other calibration disks. At least in theory, this should work better than color calibration through DVD. Not only you can use the correct input type and resolution mode, but you can correct/account for any color changes made by the STB itself and by any other equipment between the source and your TV set.

Look for "OFF AIR" sign in the program guide (except on Alt ESPN channels, which are OFF AIR all the time).

Alright...!!! Thanks Ilya I'm going to look for those tables. Have you seen them often? Any time of the day or more late night? This would be perfect!
Thanks again, I'll keep you posted.
 
truqui said:
Alright...!!! Thanks Ilya I'm going to look for those tables. Have you seen them often? Any time of the day or more late night? This would be perfect!
Several times a week. At different times on different channels. Tomorrow morning check Starz channels between 4 and 5 AM or HBOC(Ch.208) 5:30 through 7 AM EDT. Check ch.110 too - I wonder what they show on VOOM exclusives? Don't expect to see too much, but even one table is better than nothing...
 
I have a silly question:
When I view dark shots on any HD channels I see barely visible 'snow', if the shot is darker then 'snow' becomes more visible and annoying.
Any ideas on how to get rid of this?
 
yankov said:
I have a silly question:
When I view dark shots on any HD channels I see barely visible 'snow', if the shot is darker then 'snow' becomes more visible and annoying.
Any ideas on how to get rid of this?
Is this on all channels including OTA, or just select ones? If you see this on all channels, I wonder if this is a digital noise caused by the DVI cable? How long is your DVI cable?
 
Ilya said:
Is this on all channels including OTA, or just select ones? If you see this on all channels, I wonder if this is a digital noise caused by the DVI cable? How long is your DVI cable?
I don't get any OTA channels yet, hopefully SquareShooter will fix it this Friday.
My DVI cable is about 2.5 meters - standard VOOM cable that came with the box. I ordered a new DVI cable from eBay store that someone recommended here as being better than Monster it should arrive within next 3-4 days.
 
DarrellP said:
Are you sure it's snow and not film grain? HDTV's really bring out the detail.
I see it on all channels and only on DVI input, so I think is got to do with DVI cable.
I wonder if anyone knows about difference between Dual-link and Single-link DVI cables, can I use either one with VOOM?