Re: [APML] Re: (OT) IC1396 CCD with Schmidt-like FOV

[Philip Perkins <philip@astrocruise.com>]

Sean,

Please see my other post on this...  but I am surprised to hear that a 
Schmidt camera shot would need reducing to web resolution in order for the 
grain not to be obtrusive.  I assume that this experience was based on some 
high speed colour film that was not composited (or at least not composited 
correctly) - if it had been then the image should have appeared quite 
smooth and very detailed at full resolution.  I assume that it could not 
have been Tech Pan either because Tech Pan should appear virtually 
grainless, especially after a tri-colour composite.  Schmidt camera shots 
have been renowned for many years for their huge amount of detail and 
resolution, provided of course that the imaging medium is appropriate.

Noise reduction techniques can be applied to film too, and should be 
applied for a like-for-like comparison.  In most cases single CCD shots 
appear to me to have more noise in them than single film shots, especially 
in the case of a fine grained film.  Ultimately the film shot cannot 
achieve the degree of resolution and smoothness as the CCD shot, but on the 
other hand film has the big advantage of image scale and detector size (at 
least in the case of medium format) which can more than compensate for many 
types of image.

--Philip

>Philip, I have to disagree with you here- Schmidt camera shots look
>quite impressive at web resolution, but when blown up, the grain of the
>film starts to become quite apparent. Rob's response sums it up for me
>also.
>
>Sean Walker
>
>
>--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
>              Unsubscribe at <majordomo@seds.org>

Philip Perkins - philip@astrocruise.com
Wiltshire UK & Luberon France
Astrocruise - http://www.astrocruise.com


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