Archived posting to the Leica Users Group, 2000/11/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]on 1/11/00 4:44 pm, Birkey, Duane at dbirkey@hcjb.org.ec wrote: > Johnny, > > Where in the world did you come up with Erwin saying a 960 x1440 pixel image > was functionally equivalant to film??? > > No wonder you are confused..... : ) This is the bit I was referring to, Duane. He says that 40 l/mm on the negative, which he says is equivalent to a digital capture of 960x1440 pixels, is roughly equivalent to the quality 'most people would dream about' in hand held picture taking. If I have misunderstood it, please illuminate!! > Now for some steps. It is very difficult and often considered unnecessary > (pace Mike Johnston) to get on film more than 40 line pairs or 80 lines. And > if we be even more general, 20 lp/mm are the best. most people would dream > about. Assume now 20 lp/mm or 40 lines per mm (the best you can get in hand > held picture taking, generally speaking). *** BEGIN ASSERTION *** > Again: 24 x 40 x 36 x 40 = 960 x 1440 = 1.382.400. Three colours would be 3 > times this number, which is 4Mb. And with 40 lp/mm we et 5.529.600 bytes > times 3 = 16.588.800 bytes or 17 Mb, quite close to the 20 MB I quoted as > the conventional wisdom. *** END ASSERTION **** > So any digital capture of 20Mb would be close to the resoluton of 40 lp/mm > that some on this list would consider as the most one would want in 35mm > photography and to go beyond this number would qualify as being a freak > obsessed with lines and test targets and all that. Reread the mails by Mr > Johnston and Mr. Grant and Mr Goodman at all. - -- Johnny Deadman http://www.pinkheadedbug.com