--- Rob Studdert <[EMAIL PROTECTED]> wrote: >
>
> We were talking 35mm format. So what would be the
> advantage of providing more
> than 14MP density on a 35mm frame? You know that
> drawing an analogy to RAM
> capacities is entirely inappropriate in this case.
>
Pass the coffee....
Time for maths! in round figures 14Mp is; lets say
4800x2900. Take the long side of 35mm = 36mm and think
of lines per mm..... well great film and ggreat lenses
may deliver 80 lpmm but that is probably a theoretical
figure few people get in practise.... One "line" is a
discernable pair of light dark transitions so it takes
TWO pixels .... 4800/36/2=66.67 lpmm!!! we are getting
near to the best that lenses can provide..... Or are
we?
The resolution of a system of more than one resolution
is not as great as the best figure... No it is:-
1/rsum=1/r1+1/r2+1/r3 etc. so a lens that give 80lpmm
and a sensor that gives 67lpmm yealds 36.5lpmm!!..
Conclusion, there is a reason for more pixels right up
to the point where the resolution of the sensor
exceeds the resolution of the lens by an order of
magnitude (10x) Then your pics will only be limited by
the quality of the lens! That's about 1.5Gig pixels!
Anyone care to compute where in this problem the
wavelength of light will start to come into play?...
time for bed here..
Tom Addison, an electronics engineer who works for
physicists, a folk singer and flute player, Oh and
I've been using Pentax cameras since my (now ex) wife
bought me one in 1977...That's all folks..
___________________________________________________________
Yahoo! Messenger - Communicate instantly..."Ping"
your friends today! Download Messenger Now
http://uk.messenger.yahoo.com/download/index.html
