Oleg Goldshmidt wrote: > > > Also without going into the physics of it here (this is a linux > > group after all), a two million pixel camera is all that you need. > > As you know perfectly well, Geoff, I am a physicist by training. ;-)
Yes, and I would gladly discuss the subject with anyone at any time, but thought that it might not be a topic of much concern here. :-) > Is the 2Mpx number anything deeper than 1600x1200 resolution? That's exactly what it is. > This > will display on a full screen nicely on modern displays, and also will > lead to a less than 0.2 mm/px on paper at A4 size. The latter size is > less than the characteristic scale of paper surface inhomogeneities, > which is 0.3 mm for pretty high quality paper, AFAIK. Is that all, or > is there anything deeper? I don't know it by mm, but the "sweet spot" for printing color is between 200 and 300 dpi. It depends upon many factors, including pixel size (for inkjets, the size of a color dot that can be printed after the ink dries), how far you view the picture from, type of paper etc. I found by experimentation that my bottom of the line Epson 720x720 dpi printer produces just as good results when viewed (as opposed to looked at under a magnifier) as my 2400x2400 dpi HP with dropplet size control. If you have more pixels than dots per inch, the software must combine them to produce a dot. If you have less, it just streches them out. Depending upon the exact ratio of pixels to dots and the quality of the software you often loose something, and IMHO the too many pixels side is where you loose more. If you have a CCD or CMOS camera, you are not getting accurate color rendiditon anyway. The sensors only see one color at a particular point, the color information is interpolated from other pixels. This is due to the fact that the sensors see all colors from near I/R to violet and must be masked with color filters to get any color information at all. One of my favorite photographs of the last few years was taken on film black and white film and scanned at 1800x1200 (2mp). I then cropped it to about 1/4 the area in GIMP and slightly enhanced it. The ehancement was a contrast adjustment which I could have done when printing and "sharpening" which would have been more difficult. I then printed it on my EPSON 720 dpi printer in color. The reason to use color for a black and white photograph is that the color of the "black" ink that Epson uses is not to my liking and I can adjust the blackness of the ink that way. Unless you look at it close up and see that it is pixelated it looks like a good hand done photgraphic print. Geoff. -- Geoffrey S. Mendelson [EMAIL PROTECTED] 972-54-608-069 Icq/AIM Uin: 2661079 MSN IM: [EMAIL PROTECTED] (Not for email) Carp are bottom feeders, koi are too, and not surprisingly are ferrets. ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
