Ghosting, moss and other TV Nightmares - 01/31/08 11:24 AM
Alan,
I just purchased a Sony Bravia 46V2500 HD TV. I'm seeing a lot of ghosting or moss crawling in the blacks and shadows on regular stations. Also some strange layering or ghosting on faces close up. The HD channels look good. We have Dish TV. Is this a TV brand issue or signal input issue. It's not too late for me to take the Sony back to the store and get something else. Your thoughts?
Wayne
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Hi Wayne,
It's hard to diagnose exactly what's happening, but I'll start with a few tips and also add an answer that I just wrote to another customer about ghosting and dot-crawl issues he is having with a new Toshiba plasma display.
First, do you have your DishTV tuner box set to output your Sony's native resolution? That will likely be 720p (if your Sony is a 1080p set, set the HD Dish box to output 720p--you can try 1080i if you want, but the picture will likely be better setting the box to output 720 p. Try both and use the setting that delivers better image quality.
You should be using either component-video cables or HDMI from your HD DishTV tuner box to your Sony Bravia. Try each one and see which yields the better picture. Despite all the hype, HDMI is NOT necessarily superior to component-video cables. Are you connecting directly to your Sony display or routing the signals through an AV receiver? If the latter, try bypassing the AV receiver and going directly from the DishTV HD box to your display.
Now read this on the cable issue (and don't use long HDMI or component video cables, which might be causing some of your problems). Keep them to 15 feet or less.
Your component-video cables, which carry the video in analog form, may be too capacitive, so get some low-capacitance component cables and substitute them for the ones you're using now. When component cables have too high capacitance (capacitance is measured in picofarads-pf--per foot), they roll off the high-frequency portions of the video signal, which may cause phase and timing errors in your LCD display's digital chip set. That is what is likely causing the ghosting issues.
The dot-crawl issue that you see when you use HDMI connections suggests you have noise somewhere in your system. Again I'd suggest you exchange your existing HDMI cable for a different cable.
What is the native resolution of your display? Is it 720p or 1080p? Your set will automatically display all incoming signals at its native resolution, so that's what you should set your Denon 2910 to if you are using the component-video cables. HDMI connections have the advantage in that the connected devices electronically talk to each other, so your Toshiba display will automatically instruct your Denon to adjust the video output to the Toshiba's native resolution.
By the way, your Toshiba plasma can only display progressive video. It can't display native interlaced video, so its internal scaler will convert all incoming interlaced signals to progressive.
Also, try my tips in the July '07 Axiom newsletter for setting Brightness (Black Level) and Contrast (White Level).
Kind regards,
Alan
I just purchased a Sony Bravia 46V2500 HD TV. I'm seeing a lot of ghosting or moss crawling in the blacks and shadows on regular stations. Also some strange layering or ghosting on faces close up. The HD channels look good. We have Dish TV. Is this a TV brand issue or signal input issue. It's not too late for me to take the Sony back to the store and get something else. Your thoughts?
Wayne
------------------------------------
Hi Wayne,
It's hard to diagnose exactly what's happening, but I'll start with a few tips and also add an answer that I just wrote to another customer about ghosting and dot-crawl issues he is having with a new Toshiba plasma display.
First, do you have your DishTV tuner box set to output your Sony's native resolution? That will likely be 720p (if your Sony is a 1080p set, set the HD Dish box to output 720p--you can try 1080i if you want, but the picture will likely be better setting the box to output 720 p. Try both and use the setting that delivers better image quality.
You should be using either component-video cables or HDMI from your HD DishTV tuner box to your Sony Bravia. Try each one and see which yields the better picture. Despite all the hype, HDMI is NOT necessarily superior to component-video cables. Are you connecting directly to your Sony display or routing the signals through an AV receiver? If the latter, try bypassing the AV receiver and going directly from the DishTV HD box to your display.
Now read this on the cable issue (and don't use long HDMI or component video cables, which might be causing some of your problems). Keep them to 15 feet or less.
Your component-video cables, which carry the video in analog form, may be too capacitive, so get some low-capacitance component cables and substitute them for the ones you're using now. When component cables have too high capacitance (capacitance is measured in picofarads-pf--per foot), they roll off the high-frequency portions of the video signal, which may cause phase and timing errors in your LCD display's digital chip set. That is what is likely causing the ghosting issues.
The dot-crawl issue that you see when you use HDMI connections suggests you have noise somewhere in your system. Again I'd suggest you exchange your existing HDMI cable for a different cable.
What is the native resolution of your display? Is it 720p or 1080p? Your set will automatically display all incoming signals at its native resolution, so that's what you should set your Denon 2910 to if you are using the component-video cables. HDMI connections have the advantage in that the connected devices electronically talk to each other, so your Toshiba display will automatically instruct your Denon to adjust the video output to the Toshiba's native resolution.
By the way, your Toshiba plasma can only display progressive video. It can't display native interlaced video, so its internal scaler will convert all incoming interlaced signals to progressive.
Also, try my tips in the July '07 Axiom newsletter for setting Brightness (Black Level) and Contrast (White Level).
Kind regards,
Alan