Re: [APML] Going to the Luminance side?

["Shekhar Borde" <shekhar@prodigy.net>]

>
> I thought about the above some more and it is the wrong explanation. I'm glad I
caught this before anyone else did. The real explantaion is harder to make, though.
Basially, CCD can record more detail because it records higher frequency information
than film. Two CCD pixels can have widely divergent values, while film has
constraints on that.
>
> Matt
>

I think what you are saying is that CCD has a higher MTF than film for a
given frequency.  I think this is somewhat true.  A film's MTF is much more
contrast dependant than a CCD's MTF.  This is why, as Chuck points out
in another post, CCDs do a much better job at recording nebular detail.
For high contrast objects (e.g., clusters, lunar and planetary detail) a fine
grained film like Tech Pan would still be very competitive.  Unfortunately
film still loses out to CCD when it comes to speed, reciprocity, linearity,
SNR and all the other important stuff.

I am just amazed at how the CCD guys knock off 50 shots in one night in
their back yard right next to a first quarter moon.  It makes our 4-hour
no-moon trips to Chews Ridge look insane in comparison  :-)  Ah! the
things we film guys do for this damn hobby!

Shekhar



--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
             Unsubscribe at <majordomo@seds.org>