Every display has different factory default settings, picture adjustment tools, and picture characteristics. Attempting to pass judgment about image quality is a very subjective process, so some standardization of testing techniques does help us get closer to the goal of comparing "apples to apples". However, developing a good eye for various image quality characteristics can be even more beneficial.
All review units are shipped directly from the manufacturer, and most appear to never have been used. All subjective testing is performed in a light-controlled environment, with most testing performed with no ambient light; light is later added to view the affects of ambient light on picture quality. Here are some details about testing equipment:
HDTV, Digital and Analog Testing - I use a Scientific Atlanta 8300HD Cable Box with regular and HD cable service from Cablevision, based in New York. I have found the overall HD offering of Cablevision to be relatively extensive and of excellent quality. I use HDMI and component video cables from Pacific Cables.
DVD Testing - DVD tests are performed with the Oppo OPDV971H DVD player via the DVI input. I have found this player to provide very consistent performance, particularly with upconverting from 480p to 720p/768p/1080p HD displays. Again, I use HDMI/DVI cables from Pacific Cables.
PC Testing - PC tests are performed either via the DVI or VGA input, depending upon whether I can achieve 1:1, non-scaled pixel mapping with the DVI input. Frankly, I have not noticed much difference in quality between DVI and VGA. My desktop computer uses a Radeon X300 video card with both DVI and VGA outputs. I then view various content including Internet, word processing, photos and video. I also look for motion ghosting by testing several types of games, including Halo, Madden Football and others.
Video Processing Testing - When attempting to accurately judge how well a display scales images of various resolutions, I view a lot of different source material for overall image quality: analog and digital cable, DVD, HDTV and so on. Typically, HD displays have the most trouble with low-resolution sources, such as analog cable, but some displays do a better job than others at "cleaning up" these sources so they are as viewable as possible.
I test 3:2 pull down processing by viewing 24 frames per second, film-based material and see how well it is converted to the video frame rate of 30 frames per second. This is an effective way to see how fast-motion scenes are processed, and where "jaggies" or motion artifacts are more likely to appear. An example is during the movie "Assassins" where there is a slow pan up a shingled building, and the lines of each shingle usually show some severity of motion artifacts.