re more gray levels out of the screen in article pp t cc tut fi jk lehtori cc tut fi kouhia juhana writes in article apr kpc com hollasch kpc com steve hollasch writes i think you re proposal would work to get an extra one maybe two extra bits of color resolution however if you had a display that chould do only zero or full intensity for each primary i don t think you d get great equivalent bit photographs i have not suggested to do so i wrote about problems and the problem were clearly visible with bit b w images not to mention bit images description of experiment deleted if the bit images are viewed quickly and in sync with screen then intensities could be better than we have i dunno more deleted in any case getting black color with slow machines is problem i could try it on our bit screens but i don t know how to render pixels with x in constant time i recall our double buffer has other image color and one b w that doesn t help either maybe i should dump photos to screen with low level code how a few years ago a friend and i took some grey level photos from a bit mac plus screen using this method displaying all levels synchronized to the hz display took about seconds after experimenting with different aperture settings and screen brightnesses we found a range that worked well giving respectable contrast the quality of the images was pretty good there were no visible contrast bands to minimize the exposure time the display program built different bit frames the first contained a dot only for pixels that had value the second only for pixels that had value etc these frames were stored using a sparse data structure that was very fast to or onto the screen in sequence creating these frames sometimes took minutes on that old mac but the camera shutter was closed during that time anyway and yes we wrote directly to the screen memory mea culpa our biggest problem was that small images were displayed in the top left corner of the screen instead of the center it took an extra week to have the film developed and printed because the processors took the trouble to manually move the all images into the center of the print who d have guessed regards jon rowlands
