CompuServe Messages

#Output to VHS

    19-Apr-95 13:23:29
Sb: #4812-#Output to VHS
Fm: John Small 72550,2150
To: Jan Cabral 73270,3306
Jan, my genlock is 640×480 so I don't have first hand experience to know the answer to your question. NTSC is 525 lines of vertical resolution at 30 frames/sec … but only half that is contained in each field at 60 fields/sec. This interlacing reduces flicker w/o increasing the frame rate. From what I've read I believe up to a point better resolution from the source can be noted on even a lower resolution NTSC monitor. But I'm not sure how much above 525 this applies. I suppose unless other factors improve along with the resolution then anything over 525 is not a factor at the NTSC stage. But I suspect the better resolution would still make a difference in the same sense that 'bumping' the Hi8 up to a higher resolution format for editing makes a difference even at the lower VHS resolution. Of course this means you'd need something better than Hi8 as your intermediate medium. In going to 800×600, that's fine for a computer monitor but I wonder if aside from an improvement in sharpness for smaller images whether you'd really make use of the increased resolution for teaching. It's usually best to have only one new idea per 'slide', right? The additional information you could place on each 'slide' might not be a good thing unless it involved graphic images that now have insufficinent resolution. In other words the sharpness may well be real but you may be restrained from making use of this unless you're dealing with graphics that now are not sufficiently resolved, like graphs, etc. Of course, bottomline, I'm not able to answer your question … only speculate. I suspect Marc Wielage or Bill Rood, sysops on CEVIDEO, could answer your question. -jts