When I project certain DVDs I see a juddering or rippling effect. What's wrong?
EPSON home cinema projectors
Juddering or rippling effects when projecting certain DVDs
If your DVD projection is jerky or suffers from rippling or juddering effects, particularly during slow, panning camera movements, then the issue is likely to be that you are projecting an NTSC format DVD on a home entertainment system set up to use the PAL format.
NTSC is the format commonly used in Japan, the USA and Latin America, while PAL is the standard in China, Western Europe (France excepted) and many African and Asian countries.
These visual phenomena, often referred to as telecine judder, are a normal part of the image conversion process between the formats.
While the juddering is not noticeable to many people, if your DVD player supports both formats, you may be able to reduce or eliminate the effect by changing the display system from PAL to NTSC before you play the disc.
However, some juddering or loss of smoothness in NTSC format DVDs can still be expected with any audiovisual system not fitted with a motion interpolation chip. This is due to the process used to convert the cinema film format to NTSC, known as 2:3 pulldown or 3:2 pulldown.