Tom Reese a écrit : > Hey all, > > Our photo club currently has competitions in slides and prints. We're going > to combine projected digital images and slides in future contests in order to > provide maximum opportunity for participation. Members won't have to make > prints to enter contests and they'll save a lot of aggravation and expense. > > My question from other club members is: > > are you having contests with projected images? What resolution do you use for > the images? Have you had any problems? > > thanks for your help. > > Tom Reese > > Hi Tom,
My club organizes every year quite a big contest (as far as a few thousands candidate photos is considered big), and seriously considered digital projection along with slides. We discussed with other clubs and decided that we would not venture into this yet, mainly for manpower reasons (reception, sorting etc...). However, we've often projected digital in various other occasions. What we learned: The quality is certainly behind slide projection, in resolution, and specially in color accuracy and stability (compared to a reasonably good slide projector typically available in a club). Maybe it's because the digital projectors we used were bad, but this proved noticeable with various recent models. Regarding color rendition, we did not have the hardware to calibrate the projected image, though. The photos are not on the same playing ground not only depending on the support (digi vs. film), but also depending on the image orientation. While a slide can be projected vertically and horizontally with equal quality, the digital imager is a horizontal rectangle. Therefore, with a 1600x1200 imager, horizontal images will be 1600x1066, while vertical images will be only 1200*800 (2/3 images like 24x36 and APS-C). The projected vertical image will be much smaller, with the same dot size, and will lose more detail. I can see only two workaround to this: - configure the projection software or pre-process the images so the projection area is square (in this case 1200x1200). Of course this means lowering the quality of horizontal images to the same level as vertical images. - wait until manufacturers make square image projectors just for the photo clubs :-) Projecting the original files and let the projection software do the resizing and adding black borders ran smoothly for us. One would expect that if the authors knew (or guessed) the projector's resolution, they would have the chance to adapt their files to it, especially sharpening and the interpolation method if one is preferred. Interpolators used in projection software do not always give identical results. Enjoy your club activity (and the pictures) and take care. Patrice -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
