> > On Sat, 1 Nov 2003 22:38:34 -0500 (EST), John Francis wrote: > > > My current HP is 600 dpi in normal mode, 1200 dpi in best quality. > > A printer dot (in dpi) is not equal to an image pixel (in ppi). A > printer dithers a pixel across many dots to get a good approximation of > the color of a pixel. The HP printer is resampling the image to, > probably, 300 ppi, then dithering that into a 600 dpi or 1200 dpi > pattern.
Ah, but the HP PhotoPrinters also have multiple levels of intensity; they can deposit different amounts of ink at each possible position. The original PhotoSmart printer was a true 300 ppi printer, without having to dither. The current crop really are 1200 ppi (and in fact they use 1200 x 4800 subpixel dither for even finer level control).
