DVI/HDMI better than component?
Posted: Wed Dec 01, 2004 1:34 pm
DVI passes the image via a digital signal and component is via an analog signal. If your display uses CRT technology then there is no real advantage using DVI. If your display uses digital technology such as DLP, LCD, and plasma then DVI is typically preferred since it will bypass the A/D conversion process that must occur to process the image to the display panel possibly providing a marginally better image. All that said a properly designed product should have nearly the same response via either connection type making this concern moot.
There are a numerous comments on the internet that can easily leave the end user confused over benefits and then there are also the technology issues that must be observed when making valid observations.
The first thing to understand is that your display has what is called a native scan rate and you get the best image when your sources are feeding the display that scan rate. Most displays are native 720P or 1080I and some also include 480P. Most CRT technology is 1080I and some include 480P as well. Digital is typically 720P or 1080P. There are variations such as 1024X1024 which will not be native to anything requiring any input be scaled to that scan rate. None of this is related to what signals your unit will display.
The first step is determining the native scan rate(s) of your display. The next is confirming that your DVI input is HDCP compliant by checking the specifications in your owners manual for HDCP in reference to your DVI input (HDMI is HDCP by design). The final step is determining if your display will tell you what the incoming scan rate is so you can confirm that the HDCP protocol is satisfied which will allow the source to output an HD scan rate such as 720P or 1080I or check your owners manual for the source to find various ways to detect what the output scan rate is if your display does not provide this feature. Now all you do is hook up your source to the display, set it for the native scan rate and either put in a DVD in the case of a player or go to an HD channel on your STB and confirm that the scan rate has not changed. Once you have verified this you are set to make some comparisons with component but bear in mind it is not uncommon to have to adjust the picture controls to different settings with different types of inputs for your observations to be conclusive. There is also the issue of whether or not the manufacturer setup the DVI output or input for PC or video content which can cause black and white crush and variation in black level and contrast compared to component. If the source is DVD you can confirm this problem with a calibration DVD.
There have been reports of DVI/HDMI specifically the hand shake HDCP protocol not working properly which can be elusive to the end user causing one to conclude that DVI or HDMI was of little benefit. In this case often times the source will change the output scan rate to 480P without telling you this has occurred which is why I explained how to check what the scan rate is. In rarer cases you will have no image. If you are one of these unfortunate few your next step is to contact the manufacturer of your display to confirm that your DVI is HDCP compliant. Once this is verified or if you have HDMI instead of DVI then contact the manufacturer or provider of your source component and tell them it is not passing an HD scan rate and your display has HDMI or the DVI is HDCP compliant.
Regardless of whether DVI or component is better it must be made clear that if you are in the market for a new display it must have HDMI or DVI/HDCP or you are not interested. This digital connection is the future standard for the delivery of HD content.
There are a numerous comments on the internet that can easily leave the end user confused over benefits and then there are also the technology issues that must be observed when making valid observations.
The first thing to understand is that your display has what is called a native scan rate and you get the best image when your sources are feeding the display that scan rate. Most displays are native 720P or 1080I and some also include 480P. Most CRT technology is 1080I and some include 480P as well. Digital is typically 720P or 1080P. There are variations such as 1024X1024 which will not be native to anything requiring any input be scaled to that scan rate. None of this is related to what signals your unit will display.
The first step is determining the native scan rate(s) of your display. The next is confirming that your DVI input is HDCP compliant by checking the specifications in your owners manual for HDCP in reference to your DVI input (HDMI is HDCP by design). The final step is determining if your display will tell you what the incoming scan rate is so you can confirm that the HDCP protocol is satisfied which will allow the source to output an HD scan rate such as 720P or 1080I or check your owners manual for the source to find various ways to detect what the output scan rate is if your display does not provide this feature. Now all you do is hook up your source to the display, set it for the native scan rate and either put in a DVD in the case of a player or go to an HD channel on your STB and confirm that the scan rate has not changed. Once you have verified this you are set to make some comparisons with component but bear in mind it is not uncommon to have to adjust the picture controls to different settings with different types of inputs for your observations to be conclusive. There is also the issue of whether or not the manufacturer setup the DVI output or input for PC or video content which can cause black and white crush and variation in black level and contrast compared to component. If the source is DVD you can confirm this problem with a calibration DVD.
There have been reports of DVI/HDMI specifically the hand shake HDCP protocol not working properly which can be elusive to the end user causing one to conclude that DVI or HDMI was of little benefit. In this case often times the source will change the output scan rate to 480P without telling you this has occurred which is why I explained how to check what the scan rate is. In rarer cases you will have no image. If you are one of these unfortunate few your next step is to contact the manufacturer of your display to confirm that your DVI is HDCP compliant. Once this is verified or if you have HDMI instead of DVI then contact the manufacturer or provider of your source component and tell them it is not passing an HD scan rate and your display has HDMI or the DVI is HDCP compliant.
Regardless of whether DVI or component is better it must be made clear that if you are in the market for a new display it must have HDMI or DVI/HDCP or you are not interested. This digital connection is the future standard for the delivery of HD content.