Archived posting to the Leica Users Group, 2000/10/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]on 29/10/00 10:01 am, Austin Franklin at austin@darkroom.com wrote: > >> Conventional estimates say that a 35mm negative has about 20Mb > > I do not believe that's close. If depends on if you are talking about B&W > (which only has one value/pixel) or color (which has 3 values/pixel). It > also depends on film. You might be ballpark for some 6400 speed B&W film, > but certainly no where near for a 100 speed film. > > I would strongly urge you to do the arithmetic your self. Pick a good > film, take the grain size and see how many grains are in the image > area...and multiply by either 2 or 4. That'll give you a good estimate. > It's a heck of a lot more than 20M. You don't have to be really anal to > see your 20M number is way off... I agree strongly with Austin here. My guess is that for a 100 film you'd need somewhere in the 8-10000 dpi region to pull off all the detail. At 16 bits on a 35x24mm image that gives image sizes of at least 192 Mb for a bw image and 3 times that in color. Even on a Polaroid SS4000 which believe me is not pulling everything off even Delta 400, my image sizes are beyond your 20 Mb. You can do the reverse arithmetic if you like... let's say you want to print 11x14 at 300 dpi, which is certainly in the ballpark of 35mm quality. A monochrome image sneaks under your wire but a color image demands about 40Mb. - -- Johnny Deadman http://www.pinkheadedbug.com