[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: [APML] What's the Best Way to "Combine" Two ImagesofDifferingTimes?



> [...] For example, if I have a linear image
>A exposed by a factor 1, and another linear image B exposed by 0.8, the
>correct average should be (A+B)/1.8. Furthermore, if exposure time improves
>the signal-to-noise ratio, this also should be taken into account. Or am I
>completely wrong (I reserve that right :)?
In terms of intensity, you are right, but SNR remains the same. The sum of the weights is just a scaling factor, that is vanished when you perform the division between the signal and the noise (intensities). This is also the same reason why it is the same adding and averaging.
 
 


Regards,

Carlos Milovic F.
-------------------------
Astro & Photo - CMF
http://www.astrophoto.vze.com
-------------------------
Visita "AstroFoto", el foro de astrofotografía en español
http://espanol.groups.yahoo.com/group/astrofoto


Correo Yahoo!
Comprueba qué es nuevo, aquí
http://correo.yahoo.es
_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo