Epson printer drivers will not go above 360 dpi. send higher resolution (i.e. 6Kx4K for a 4x6 print) and it will downsample. i suspect Canon ones are the same with a different number, probably 300dpi since their quoted printer resolutions are multiples of 300.
Herb... ----- Original Message ----- From: "Cotty" <[EMAIL PROTECTED]> To: "pentax list" <[EMAIL PROTECTED]> Sent: Friday, October 31, 2003 4:33 AM Subject: Printer resolution (was: Re: posted *istD Samples) > Off the starting blocks I have always been printing at 300 dpi and always > been very happy with the results. I think I tried 200 dpi once and > noticed the difference. My image size out of the (light-tight) box is > 3072 pixels by 2048 pixels with a file size in Photoshop of 18 MB (from a > large/fine jpeg). > > If I change the resolution to 300 ppi (without changing the dimensions - > file size - that is without getting Photoshop to interpolate extra info > into the image) then my physical size of print will be 26cm by 17cm or > thereabouts. That's roughly 10"X 6 1/2". So at 300 ppi, if I want to fill > a nice A3 print, I would normally increase the size to (say) 40cmX26cm, > also increasing the pixel count from 3072X2048 to 4724X3150, and bumping > up the file size from 18 MB to a whopping 42 MB. Photoshop interpolates > very well and the prints are really nice. > > But now if I change things slightly and select a resolution of 240ppi as > Mr Evening suggests, the size increase is much less in terms of added > Photoshop interpolation. 3072X2048 goes up to 3780X2520, and file size > jumps from 18MB to only 26MB.
