Archived posting to the Leica Users Group, 1999/10/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 6:25 PM -0300 10/14/99, Robert G. Stevens wrote: >Nikon needs the ICE because it picks up all the backing scratches on most >films. My Polaroid that uses a florescent tube only picks up deep >scratched or emulsion scratches. For scratches on the backing and those on >the emulsion that do not penetrate the dye layers, a touch of nose grease >fixes them up for scanning, just like you would do for printing. > >In my opinion, the most important feature of a SLIDE scanner, is its Dmax >range. The scanners with a DMAX of 3 or so will not scan slides and give >sufficient shadow detail, particularily slightly dark slides. At 3,5 or >more, the Nikon is better than the 3.4 of the Polaroid. Nikon scanner >owners always quote the ice feature, but they should be quoting the high >Dmax of the LS2000. I guess the ICE is always quoted because the Nikon >approach to scanning makes scratches more evident to the user. Another >thing never quoted is with the use of ICE, sharpness is reduced. > >Remember, Dmax is the sign of a great scanner, not ICE. Nikon is the king >of good Dmax in the consumer level scanners. I had the Polaroid 4000 and Nikon LS-2000 at home for a couple of days at the same time. The price difference was about 12% to me at the time. I decided on the Nikon. The ICE feature was nice, but only a bonus. The true difference was the Nikon had better Dmax (actually, about 2.5 or so) vs. the Polaroid at 2.3 or 2.4 approx. The Dmax on scanners is generally vastly overstated. No CCD scanner that I know of that has been accurately tested can handle a Dmax of over 3.0 (we're talking $30,000+ here). In addition to the intrinsically higher Dmax of the Nikon scanner, it also has the multisampling option. That is its true strength. With the 16x multisampling to cancel out the background CCD noise to a large degree, it can show useable detail in Velvia slides that the Polaroid is completely incapable of handling. The Nikon is the first desktop scanner I've tried that can compete at a level of the Kodak PhotoCD scanner with respect to dynamic range and Dmax. I bought the slide feeder with the Nikon scanner, and now scan with the new software (2.5) at 12 bit depth, 16x multisampling and ICE turned on, and let it collect 50 slides at a time. Takes nearly 3Gb of hard disk space, but worth it. I then do some correction with levels, curves and very mild sharpening, and save as 8bit jpegs in Photoshop at the highest quality level, which is lossless. Note that _only_ the _highest quality_ level is lossless; all the other levels use a lossy posterization technique, and should not be used unless you will no longer work on the files. I then save the resulting files, of around 10Mb, to CD. The Polaroid software I used was dismal, to say the least. It was barely useable, and certainly not in a production setting. I'm sure they will improve it, but the basic stuff is terrible. In any case, the Nikon's higher dynamic range and higher Dmax capability will always be the better choice for transparencies, unless the hardware has capabilities the present software knows nothing about. My platform is a 400Mhz G3 Mac clone with 500+Mb of RAM. I'll post some new stuff from my scans shortly. * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com