At 12:08 PM 11/28/98 -0800, John Petrush wrote:
>"wonky"?? Is that a technical term <g>.
In my vocabulary, yes. ;-)
>...with an
>astro CCD one takes two exposures to get a picture - a "dark frame" and the
>image itself. The dark frame is all black, except for the noise patterns
>for that CCD. The dark frame values are then subtracted from the image
>values to produce the first generation image.
Interesting. From what you mentioned above, John, I'm assuming that the noise
characteristics of the specific CCD field are always the same? Sure makes it
easy to manipulate, if that's the case. I also assume that Sebastien would
have to make "dark field" exposures that are always the same elapsed time as
the actual subject exposure, in order to do this subtraction properly...
Garth
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|