> But if starting from an image at say 360 ppi at final size, then comparing > 300 ppi or 260 or any other number to see what happens at output - will > involve resampling down to the other resolutions at the same print size. > This will soften the image, the more so with greater reductions of > resolution. > This is not the same as the original data and may lead to less than > scientific conclusions based on the amount of pixels discarded and how this > plays with the image content at hand.
Stephen I will get only once more into this to try to understand things better myself, since your scientific approach, or your search for objective variables to evaluate is still lacking some formality. My point in discussing wether to work with LowRes files ( 150, 180, 200 dpi, you name it) for Epson Printing as being "subjectively" equivalent to the use of higher resolution files comes merely from fact that the Epson Driver will dump excess info anyway ( according to what the driver considers excess, and provided the Drivers are doing actually doing the dumping) , it then logically follows that a) Either there is a smoothing in the Epson Print due to downsampling on the fly or b) The Epson driver is taking care of some level of sharpness to accomodate the induced softening due to data dumping ( or downsampling-on-the-fly, you name it at will). Then it follows that sending ultra Hi Res files to the Driver will just provide of a slower process to get the print- more time to get the same thing- and the extra resolution - over the top accepted by the Driver- will not help a bit in producing a higher quality print( neither a sharper one). Should some "details" like banding or any other issue show up, they are not to be attributable to the low res file( or should I say, Optimum Resolution File?), but to other issues( profiles etc) affecting the printed result. At least that is my current understanding on this subject. Please enhance or correct me if this is wrong. >Sharpening can also be hard to > evaluate, the resampled images should have some USM, but how to be objective > that all the different pixel dimensions and sharpening are the same and that > this is not what makes the image look better, rather than the resolution. Effectively, all these tests can only provide a subjective approach to what is best FOR EACH OF US, but again, that is one of the beauties of Digital, the ability of having all of us using the same machines but obtaining altogether different results. Otherwise, Digital would be putting uniformity and a homogeneization in our work. This discussion, taken to the limits of formal ,objective tests, will probably drive to the conclusions you yourself and others have clearly explained about how close we can get to reproduce a Macbeth Color Chart, and how little resemblance with reality ( or our perception of reality) and how far from a good color rendition of various average subjects can we get by using curves and adjustment layers etc, as they apply to obtain the perfect chart. Likewise, the perfectly upsized, perfectly sharpened and perfectly printed file is probably just boring to see. > when doing cosmetic > work, either product shots or female faces, Res 14 or 16 scans were often > common, to help smooth out fine sharp lines and to 'oversample' and > smoothout the skintones. This was a case of intentionally providing more > data than what would be required for an 'average' image in the same > conditions. Again, scanned files are always "dirtier" than files from cameras and this has to be put into the oversampling dilemma just as well. Now, having files printed a 175 lpi output , instead of the classic 150lpi, theoretically requires higher res files (350-400 dpi ), but would be justified on the fact you would actually be able to see more detail in such print, pretty much in opposition to Epson Printing, where you will only waste more of your time to get the same thing. However, it's been ages since I have been asked to deliver a 400 dpi file for a better rendition. Don't exactly know what this means. Regards. Jorge Parra =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
