There is more than one question here: when I create a picture for the screen, I create a jpg with 72 dpi and 20% compression. This seems perfect for putting my pix on the web. However, at one location where I store my pictures, they say they will send me high-res prints of my pix.....I don't understand how a 72dpi pic can be blown up and printed in high-res. When the picture starts out, it's humongous, and I immediately shrink it to 40% it's original size. This blurrs the picture and I have to sharpen it a bit. Now my printer prints 14400 dpi. I assume that a TIF image is the best for printing, but I don't have room on my hard drive for TIF images with 14400 dpi. I always keep the originals, just in case I want to print them, but what resolution should I keep for good color printing? Black and white requires only 125 dpi. Hmmmm.

-- David Bonello (qigung@aol.com), November 10, 1999

Answers

A number often quoted for high qulaity photo printing is that you need about 150 dpi in your image. I think you meant to say your printer is capable of 1440 dpi... but even this is not a real number (assuming it's an Epson, for example). Pixels per inch in your image are not same as ink dots per inch from your printer. Read here to learn more on this subject --> http://www.imaging-resource.com/TIPS/PRINT1/PRINT1A.HTM Now, as you mention, 72 dpi is useful for DISPLAYING images. The fact that an image is 72dpi on your screen tells you nothing of how it will print when it is resized. You also need to know the dimensions of the image. An image from my 1600 X 1200 camera will be 72 dpi on my display if I try to display it full size - about 22" X 16 ". If I resize this to 8 X 10 for printing, it becomes a perfect 150 dpi if you keep the file size the same (so as to not lose any image data).

Frank

-- Frank Dittmann (dittmann@pathcom.com), November 11, 1999.