Just to add my $1.00 worth. I use an Epson 1280 set to 1440 X 720 and use the Epson inks and Epson heavy weight matt photo paper. I import my images using the Epson Print Image Matching plug-in for photoshop. I have recorded on my Sony DSC F707 (5MP) camera both TIFF and JPEG images. I have compared the final print from the TIFF image file of 11MB vs the JPEG image file of 3MB and there is no visual difference. The DPI is about 250 and it appears that the 1280 injet printer can produce excellent results at this level. The high resolution image matches what I saw when the image was captured. Richard Cooper ----- Original Message ----- From: "David Dyer-Bennet" <dd-b@dd-b.net> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@listserver.isc.rit.edu> Sent: Tuesday, October 15, 2002 6:01 PM Subject: Re: file formats > Rob Miracle <rwm@photo-miracles.com> writes: > > > At 01:05 PM 10/15/2002 -0500, you wrote: > > >I've seen sufficiently many reports of people seeing improvements in > > >Epson inkjet output at ppi values up to 720 that I don't consider 240 > > >to be optimum. It's more like "minimum professional level" or > > >something -- despite the fact that I've passed off 150 ppi Epson > > >prints to professionals on occasion (it all depends on the subject, as > > >usual). > > > > If you print 720 dpi, you will only get 1 pixel vertically since most > > of these printers only print 720 dpi vertically. So each pixel will > > be represented by a grid thats 2 x 1 on a 1270, or 4 x 1 dot grid for > > the 1280 (2880 x 720). For the Epson 2200, at 2800 x 1440, your dot > > grid is 4 x 2. It can't lay down enough color combinations to dither > > the apparent continuous tones needed to make it look like a photo. > > What most likely happens is that if you print a 720 DPI image to the > > Epson print driver, it probably resamples the image so that it will > > have enough ink dots per inch to print each pixel. > > I'm sure the driver doesn't use the ppi of the image I send for > anything at all. But I think it looks at the amount of data it has, > and uses the data in complex ways, and I don't find it unbelievable > that people see marginal improvements with additional data above 240 > ppi. The driver is *already* doing very complex playing with the > image -- mapping a pixel to a fixed region on the paper is *not* what > goes on in Epson drivers. > -- > David Dyer-Bennet, dd-b@dd-b.net / http://www.dd-b.net/dd-b/ > John Dyer-Bennet 1915-2002 Memorial Site http://john.dyer-bennet.net > Dragaera mailing lists, see http://dragaera.info > > >
