Archived posting to the Leica Users Group, 1997/12/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Tom wrote: > >>Keep these numbers in mind: >> >>600 DPI printer: 85 line screen (LPI) >>720 DPI printer: 100 line screen (LPI) >>1400 DPI printer: 150 line screen (LPI) >> >>Now, you need an image file that has a PPI of about double your target LPI. >>(You can often get by with 1.5x.) So, a 600 DPI printer needs a 170 DPI >>file. A 1400 DPI printer, like the Epson Photo needs a 300 PPI file. And Nick replied: >The Stylus Photo, I believe, is 720 X 720. The Stylus 800 is 1440 X 720. > >For printers like the 800 should we use the higher resolution, the lower, >or in-between, when figuring possible LPI? > >Please understand I am not taking issue with Tom. Just a footnote. > My understanding of the relationship between pixels per inch and dots per inch is that you'll get better printing quality if the number of pixels per inch is EXACTLY divisible into the number of dots per inch selected on the printer. This prevents the printer software fudging the image because it can't print an exact number of dots to represent a pixel. So for instance, on the Epson Stylus Photo (very good printer, BTW) at 720 dpi, output in ppi could be (amongst other numbers): 72, 80, 90, 120, 144, 180, 360, 720. Forget where I read this, but it makes sense to me and certainly seems to be borne out by the results. Am I right? If not, would someone more experienced with digital imaging please enlighten me. Slan Alex Alex Hurst Cork Florists 19 Winthrop St, Cork Republic of Ireland Tel: +353 21 270 907 Fax: +353 21 271 248 email: corkflor@iol.ie Website: http://www.flowerlink.com/corkflorists Home website: http://homepages.iol.ie/~corkflor/