> I've just bought an epson 950, and have a query: > > In print quality you can choose to print up to 2880 dpi, > but if your original image is say 350 dpi (10x8in) do > you gain any benefit choosing to print 2880dpi? no, you loose quality (and get a leetle tiny print) bare with me while I go through this.. 'printer reslolution' relates to the number of dots the printer can lay down per inch. The more it can do the better. 'print resolution' is a number which basically informs the printer how big you want this image to be, nothing more, nothing less. lets say you open a pic in PS and it's 3000 pixels wide - forget the height at this stage. if you set the res to 300dpi it will scale to 10 inches wide (3000 / 300 =10) and look very pretty to our eye :-) If you scale it to 100 dpi, you are telling the printer you want this image to be 30 inches wide, but it'll look like crap as the human eye can easily differentiate between 100 dots per inch :-P (300 ish is a good number) But if you were to have scaled it to 1500dpi, the image will be only 2 inches wide .. big file, small pic. OK, so lets assume your printer can actually print at 1500 if you DID set this res, you'd be forcing the printer to place EACH AND EVERY DOT where you specify it and that's not a good thing because 1. it takes heaps longer to transfer that data to the printer resulting in longer print times and 2. you are telling the printer to decide which ONE of it's 6 or 7 colours to use to render a pixel which may be 24 bit! what that means is you may have a pixel with 100y 240m 30c 40pm 60pc and 47b as it's colour but because you've specified that the printer print this image at it's full resolution (1500) and it can only PRINT 1500 dpi, it must decide whether to lay down either a single y,m,c,pm,pc or a black dot ... not good.. The only thing worse than the above would have been if you'd set the res to 1500 dpi and then resized it back up to 10 inches wide <eeeek!>, effectively havng PS make it now 15000 pixls wide and adding a whole 12000 pixels worth of interpolated, superfluous data! 600 dpi is overkill, go back to 300 dpi and you should be happy with the way the printer scatters all of it's 2400 dots to achieve the resolution of 300 (effectively allowing it to place 8 dots per pixel). The true photo printers (ie the Pegasus) may only print at 300ppi - but each pixel is one of 24million colours, hence the superior output at lower resolution. clear as mud, right?
