I don't know anything about your particular TV, and I am not completely sure how the Iscan controls work, but here is my theory:
The Iscan controls are probably useful in matching the input signal to the dynamic range of the Iscan circuits. So you would use it to compensate for signals that are either too strong or too weak etc. For instance if the highlights are getting clipped (blasted out) by the Iscan, then you would turn down the Iscan contrast so they look smooth.
The Set's controls are useful for adjusting the overall brightness and contrast of the final image.
So the short answer is that both are useful and might need to be adjusted correctly to get the best image quality.
But the best beginner approach would probably be to leave the Iscan controls alone and adjust your set. Once you get more advanced you may find there are problems that you cannot correct with the set's controls and you need the Iscan controls for that.
A quick analogy that might be useful in explaining why there are two sets of controls: The Iscan controls are like the exposure (aperture/shutter) on a camera, while the Set controls are like the enlarger exposure controls that you use when making a print. The point of the analogy is that both types of controls adjust the picture at different points along its journey, and they can compensate for each other's mistakes to some degree, but not completely.
[This message has been edited by Tom Morrow (edited 03-09-2001).]
I just had my Mitsubishi WT-46807 ISF calibrated by Kevin Miller. Kevin said although the iScan's controls are useful in some situations, for the most part he leaves those controls in the middle position and adjusts everything on the TV's controls themselves. My guess is that the iScan's controls are useful when your TV set does not have an A/V input memory function, which would memorize the settings for each separate input. If your TV does memorize the settings for each individual input selection, then using the iScan's controls are redundant and not necessary.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!