r, You are on the right track. Your question has to do with final output or print size while the thread so far I believe has been about display on a monitor. The image size on a monitor is a function of the image pixel count and the monitor "resolution" - higher resolution monitors will show smaller displayed sizes than those with coarser resolution. When it comes to printed output then you can specify how big you want the print to be and the same picture data will then be spread out over smaller or larger areas of paper - effectively making the dots on the paper larger or smaller depending on how many you have available originally to fill a given distance on a piece of paper. Generally, at the printed side of the house 300 dpi is asked for by printers to assure high quality reproduction. (I think you don't quite need that but ...) If you will be printing with an ink-jet printer or similar this can go down to 150 or 200 dpi I think). So given a fixed pixel count from the camera you can get the theoretically highest printed quality by making that data fill a very small printed reproduction. On the other hand, fitting all that data on a screen will result in very large display sizes on a monitor which has a fixed "pitch" so to speak. In this case you downsample a file to make it fit the intended purpose. quack reply before coffe this morn ... andy > Further investigation has shown me that unchecking the "Resample Image" > box will, when changing the 72 to 150, give me an image which has gone > from 31.556x23.667 inches to 15.147x11.36 inches while retaining the > 2272x1704 pixel count. A change to 300 dpi will afford me an image > 7.573x5.68 inches with a 2272x1704 pixel count. > Will not an image print better at 150 or 300 ppi than at 72 ppi? > If the answer is yes, then... > Is this in fact the best way to change the ppi of an image? Or dpi if > you are considering, as I do, each pixel to be a digital dot. > r > > A typical digi cam produces an image that is n > > x m pixels, that's it. If you wish to believe the pixels are 25.4/72 mm > > apart, you may, but I prefer to think of them as reaching parsecs across > > the universe. It simply doesn't make any difference. > > > > How many prime numbers are there between 10 and 20? (Hint: 11, 13, 17, > > 19) OK, so what is the average distance in Greek gallons between prime > > numbers in this range? How many miles long is pi? How many kilometres? > > > > Arrgh. > > > > Brian Chandler > > ---------------- > > geo://Sano.Japan.Planet_3 > > Jigsaw puzzles from Japan at: > > http://imaginatorium.org/shop/ > jerk! jeez. worse than me AND jan put together.
