splain somethin to me, DPI vs resolution

Rob Belics · February 27th, 2004, 10:02 PM

Now you see why I would never use a zoom lens with film.

Jeff, you said film was 'rated' at 4000ppi. Off the top of my head I don't feel like translating that into line pairs but I was talking about film and not lenses.

Dots per inch is the ability of the printer and have nothing to do with resolution of your camera or scanner.

Pixels per inch determines how big your image is printed. So a 4k by 4k image printed at 1000 ppi will be about 4 inches wide.

If your printer can only print 300dpi, then it can't resolve those other 700 pixels in an inch.

Jeff Donald · February 27th, 2004, 11:21 PM

Yes, by most accounts your printer needs to be at least 1200 dpi to produce photographic results. However, the file you print needs only be around 300 ppi (240 ppi to 360 ppi) to achieve photographic quality.

Under ideal conditions film can resolve more line pairs and produce larger files than I stated. But those conditions are rarely met by most amateur photographers. It requires very low ISO films, very expensive lenses, perfect exposure, use of tripod and mirror lockup etc. Then you need to be willing to spend thousands to purchase an 8000 ppi scanner. Since all of these conditions are rarely meet, the average film scanned won't even come close to 4000 ppi quality.

February 27th, 2004, 11:21 PM	#17
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Yes, by most accounts your printer needs to be at least 1200 dpi to produce photographic results. However, the file you print needs only be around 300 ppi (240 ppi to 360 ppi) to achieve photographic quality. Under ideal conditions film can resolve more line pairs and produce larger files than I stated. But those conditions are rarely met by most amateur photographers. It requires very low ISO films, very expensive lenses, perfect exposure, use of tripod and mirror lockup etc. Then you need to be willing to spend thousands to purchase an 8000 ppi scanner. Since all of these conditions are rarely meet, the average film scanned won't even come close to 4000 ppi quality. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

February 27th, 2004, 10:02 PM	#16
Rob Belics Major Player Join Date: Apr 2003 Location: St. Louis, MO Posts: 581	Now you see why I would never use a zoom lens with film. Jeff, you said film was 'rated' at 4000ppi. Off the top of my head I don't feel like translating that into line pairs but I was talking about film and not lenses. Dots per inch is the ability of the printer and have nothing to do with resolution of your camera or scanner. Pixels per inch determines how big your image is printed. So a 4k by 4k image printed at 1000 ppi will be about 4 inches wide. If your printer can only print 300dpi, then it can't resolve those other 700 pixels in an inch.