I don't know they might be using it but in CCD astrophotography you take one shot of a nothing frame, like maybe the inside of the lens cap, and use the noise you find in the pixels to subtract the so-called dark frame from each real shot. This reduces the amount of noise that gets into a shot. So the amount of noise has only a very small effect on the final image because all or most of it is being subtracted prior to the final image. By the way with CCD/digital imagers the higher the ambient temperature the more noise you get. Kent Gittings
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Frantisek Vlcek Sent: Thursday, December 13, 2001 5:25 PM To: [EMAIL PROTECTED] Subject: ? PShop darkframe subst Hi, anybody knows what this technique is? I heard E-20 digicam uses darkframe substitution to reduce noise, any pointers on it in photoshop? I wanted to postprocess my digital files, removing noise already with LAB mode or quantum mechanics, but neither is much good for luminance noise. Thanks! Good light, Frantisek Vlcek - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org . ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ********************************************************************** - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
