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At 12:46 PM 8/4/99 -0400, you wrote: > I'm told no photographic paper has resolution >better than 200 dpi, so scanning it at 300 dpi will not buy you anything, I've heard this before, and always wondered whether it was one of those cases where those who aren't fussy say there's no real difference and those who are fussy say there's a very real difference. So I checked it out. THE PRINT: 6" x 9" photographic print on Ilford Ilfobrom, enlarged using either a Schneider Componon or a Leitz Focotar enlarging lens. THE NEGATIVE: B&W, probably Tri-X developed in Ilford ID-11plus. THE CAMERA: probably my Leica M-3/35mmSummicron, definitely on a tripod. THE SCANNER: Microtek x6EL. THE SCANS: 150ppi, 200ppi, 300ppi, 400ppi, 600ppi, 1200ppi. RESULTS: There are clear gains in information up to 600 ppi. At every level below that, pixellization obscures details which are clear in a higher rez scan. Comparing the 600ppi (optical max) to the "1200" ppi (stepper motor max) at the highest magnification before pixellization becomes visible, there's little to choose between the scans: very slight difference which falls into the resolution/accutance pattern described recently by Arnold Gassan. That is, the higher rez scan (1200) looks a wee tad softer, but with a wee tad more detail (maybe); the lower rez scan looks a wee tad "sharper," that is, harder edged, but (maybe) losing just a wee tad of detail. Comparing the 600ppi and 1200ppi scans at the lowest magnification which shows any pixellization in the 600ppi, it's clear that extremely subtle shapes are obscured by pixellization, but unclear whether the greater detail in the 1200ppi scan is "real" information of simply the lack of visible pixel edges (that is, whether the interpolation involved at the stepper motor's maximum resolution is just averaging). Remember this is a scan of an enlargement from 35mm, made from a Tri-X neg: hardly the last word in fine detail (although the lenses and technique were very good). One of these days, I'll dig out a 4x5 neg, make a contact print, and repeat the comparison. My suspicion, based on the perceptual difference between enlarged 35mm Tri-X and a 4x5 contact print at the eye's level of magnification, is that there well be clear, scan-able detail available at over 600ppi. Is this level of detail visible to the naked eye? Certainly, but those of you familiar with larger format photography know that the difference is often described less at the gross level of, "see, there's a blade of grass on the contact print that you can't see on the enlargement" than it is at the more subtle level of, "see, the contact print just looks more real, more modelling, more real textures" etc. Is this level of detail important? That's an aesthetic question, and depends on the image, intent, etc. But back to the original question: can there be detail in a photographic print finer than 200ppi/dpi? Unless there are flaws in my methodology I haven't thought of, the answer to my eyes is a clear yes. Regards, Mitch Valburg - Please do not include an entire message in your response. Delete the excess. http://www.leben.com/lists for list instructions.
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