HDTV Test Patterns

Test patterns for standard definition DVD are available on a variety of home theater calibration discs and test patterns for HD-DVD are available on the Digital Video Essentials disc, but test patterns to calibrate your HDTV broadcast, satellite, or cable signal can be more difficult to come by.

Test Patterns On Cable

The majority of HDTV viewers receive their programming through cable. Many cable providers carry a channel called INHD. INHD is a free HD channel from the company that brings you the INDemand pay-per-view and video-on-demand programing on your cable network. There was also briefly an INHD2, but it has been phased out. The company is jointly owned by Comcast, Cox, and Time-Warner. Conveniently these companies also happen to own the majority of cable networks in the US. That means there is a good chance that your cable company's HD package contains INHD.

INHD broadcasts a set of test patterns once a week on Sunday at 4am PST. Check your local listings to confirm the broadcast time in your area. The program is usually called "INHD Tune-Up" or "INHD Home Theater Tune-Up". Many of the patterns are slightly bizarre in that they are circular, which looks cool, but can make them a bit difficult to measure with a probe or to compare against split screen patterns from a video processor. The patterns switch every 2 minutes, which can be a bit too fast for those without a TiVo/DVR to pause or rewind the sequence. The sequence includes a helpful voice over which explains how to use the patterns. The sequence also includes multichannel audio setup signals, which is a very nice addition.

INHD Test Patterns

- Brightness
- Contrast
- Color
- Convergence
- Overscan
- 5.1 Audio Setup

Some cable providers alternatively (or additionally) carry a channel called HDNet which also broadcasts some good HD test patterns. These cable providers include some Time-Warner providers, Adelphia, Mediacom, and Charter. Since HDNet is the main provider of test patterns on satellite HDNet is covered in the satellite section bellow.

Test Patterns On Satellite

DirecTV and Dish provide US satellite TV programming and both carry HDNet. Additionally a few cable providers, some of whom are listed above, carry HDNet.

HDNet broadcasts test patterns about once a month. They used to consistently broadcast test patterns every week on Tuesdays,, 4am PST, but their schedule seems to have gotten more sporadic recently. Check your local listing for times in your area. The program is usually called "HDNet Test Patterns". The patterns are traditional rectangular test patterns (as opposed to INHD's circular patterns). This more standard shape is generally easier to measure and compare with references than INHD's circular patterns. The HDNet patterns switch every 3 minutes, which is longer than the INHD patterns, but still a bit fast for those without a TiVo/DVR to rewind the sequence. There are no audio patterns. This is unfortunate, but don't forget that most receivers don't give the an opportunity to tune per input audio calibrations anyway. The sequence includes a voiceover, but it gives very little guidance on utilizing the test patterns.

HDNet Test Patterns

- Color Bars and Grayscale
- Convergence
- Registration
- Resolution / Overscan

Test Patterns On Broadcast

Since over-the-air channels vary so much depending on location it is impossible to create a complete list of all channels offering test patterns. Many channels offer at least traditional color bars during their SIGN OFF period, but comprehensive HD test patterns are harder to come by.

Problematic Test Patterns

When an HBO SD or HD channel signs off it often puts up standard color bar patterns. HBO is the greatest of all premium channels, but unfortunately their SIGN OFF color bars cannot be trusted. I have found that these patterns have major problems with color accuracy. They should not be used for calibration.


Copyright 2006 GADGETBENCH