Video scalers can be both a blessing and a curse. While a scaler will allow us to adjust the input resolution or even the format to match a specific output format, it does not guarantee our image quality.
Most projectors topped out at SXGA+, giving them 1050 pixels. So what happens to those other 30 lines of information in a HD 1080 frame? They get lost in the scaling. They can either be thrown out and part of the image is cut off, or they get squeezed in and the image has this very slight fuzzy appearance where it occurs. On an SXGA+ screen trying to reproduce a 1080 image, the distortion is slight and often unnoticed except by a trained eye.
All of the major and most of the minor projector manufacturers have taken care to install good quality scalers onboard their projectors. Still, just like in audio world, there are a number of even better quality outboard scalers that do amazing jobs of helping us get our images under control.
– From Paul J. Duryee’s Video World article in the Upcoming August PLSN
