OK, I give up, I'm beginning to sound like an echo in here... You're just one step (or more) ahead on me each time I post... I best read your replies before answering ;-)
Art [EMAIL PROTECTED] wrote: > If the optical resolution is variable and YES there are scanners that > can do it (they have to be able to change the distance between the lens > and CCD (CMOS) to change the resolution, then be able to move the > Lens-CCD assembly into the new focus position. Needless to say, this > generally is in the realm of higher-end scanners. > > If the resolution is variable and the scanner can achieve 2,400ppi over > a 1" wide path, then it will achieve 480ppi over a 5" path (2,400ppi/5in > = 480ppi simple arithmetic). > > You can set up a simple ratio if the original strip is something other > than 1"... > > Original Resolution New Resolution > ___________________ = ___________________ > Original Scan Width New Scan Width > > Fill in what you know and solve for what you don't. It works every > time, IF the scanner has variable resolution (many don't). Remember, > you can never exceed the maximum optical resolution of the scanner. > > Mr. Bill > > > Laurie Solomon wrote: > >>Maybe my math is bad; but if it has a native resolution of 2400 ppi/dpi >>scanning 1" film, then my math says it will have a native resolution >>scanning a 5 inch subject which is much lower than 300 ppi/dpi >>independent of the light path factors(e.g., around 75 ppi/dpi). For the >>size print that the original poster mentioned which was smaller ( but I >>forget the exact size but I think it may have been either a 3.5 x 5 or a >>4 x 6), the native optical resolution would be in the range of about 150 >>ppi/dpi to 300 ppi/dpi. >> >>But this is based on the assumption that a scanner can have variable >>native optical resolutions; however, to the best of my knowledge and >>understanding, scanners have a single native optical resolution. The >>effective optical resolution is a by-product of the number of inches >>that one divides into the native optical resolution. Thus, an >>enlargement of the image without any interpolative resampling will >>result in a lower effective resolution while the reduction of the image >>size without such sampling will result in a higher effective resolution. >> >>Nevertheless, it is still unclear to me if you are saying that the >>native OPTICAL resolution of this scanner is variable or not; and if >>not, if the native OPTICAL resolution of this scanner is 2400 ppi/dpi or >>something else that would produce an effective native resolution of 2400 >>ppi/dpi when scanning a 1 inch horizontal length as opposed to some >>other horizontal length. > > > ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body