On 31/10/03, [EMAIL PROTECTED] disgorged: >> > The 11" print was then compared to a 11" print I made from >> > scanned 4"X5" ektachrome 100. The ist image has remarkable lack >> > of grain/noise and looks virtually as good as the 4x5 print >> > in that respect. The resolution however is clearly not at >> > the same level when examining with a loupe. This is exactly >> > as I expected. > >But, how many people view an 11" print through a loupe. Most folks hang one >that size on the wall and view it from several feet away.
This raises a very interesting point. I have been re-reading Photoshop for Photographers by Martin Evening and I came across a section on printing resolution that I didn't recall. In it, the author says that 'the optimum pixel resolution [of the printed image] should ideally be the printer dpi divisible by a whole number. The following pixel resolutions should be used [for a 1440/2880 printer] : 144, 160, 180, 240, 288, 320, 360. To make large inkjets for viewing at a greater distance, use a low pixel resolution. For smaller sized portfolio prints I normally use a 240 ppi resolution. I doubt very much you will notice any improvement in print quality if you choose a resolution that is higher than this.' This subject has been discussed on the list before, but what with the recent arrival of the *ist D into many eager Pentax user's hands, it may be of interest again now. Off the starting blocks I have always been printing at 300 dpi and always been very happy with the results. I think I tried 200 dpi once and noticed the difference. My image size out of the (light-tight) box is 3072 pixels by 2048 pixels with a file size in Photoshop of 18 MB (from a large/fine jpeg). If I change the resolution to 300 ppi (without changing the dimensions - file size - that is without getting Photoshop to interpolate extra info into the image) then my physical size of print will be 26cm by 17cm or thereabouts. That's roughly 10"X 6 1/2". So at 300 ppi, if I want to fill a nice A3 print, I would normally increase the size to (say) 40cmX26cm, also increasing the pixel count from 3072X2048 to 4724X3150, and bumping up the file size from 18 MB to a whopping 42 MB. Photoshop interpolates very well and the prints are really nice. But now if I change things slightly and select a resolution of 240ppi as Mr Evening suggests, the size increase is much less in terms of added Photoshop interpolation. 3072X2048 goes up to 3780X2520, and file size jumps from 18MB to only 26MB. I don't really have a question in starting this thread, rather just the above observations. It's my last day off sick (I'm feeling much better after being attacked by a flu bug) so I'll be using a bit of ink up doing some tests. Any thoughts / comments / pointers ? How do you do it ? Cheers, Cotty ___/\__ || (O) | People, Places, Pastiche ||=====| www.macads.co.uk/snaps _____________________________ Free UK Mac Ads www.macads.co.uk
