Not at all. CoC is noramally defined as the acceptable "unsharpness", still accepted as "sharp" in a final images. CoC has nothing to do with HOW or by what means the image was made. However, this acceptable level of unsharpness is often defined differently for different formats. But this was not the subject. The subject was which lenses (focal lengths) will record which images.
Bringing CoC in to the discussion is not helping anybody to undserstand the basic fact, that the same lens produces basically the same images, regardless of the camera or sensor used. How you an I may assess the final results is not relevant to the subject. CoC is a relativ term designed to establish a commonly accepted measure for acceptable unsharpness. It's an agreement in the photographic industry. Not a scientific property of optics. Regards Jens http://www.jensbladt.dk -----Oprindelig meddelelse----- Fra: Adam Maas [mailto:[EMAIL PROTECTED] Sendt: 24. marts 2006 21:59 Til: pentax-discuss@pdml.net Emne: Re: crop factor vs. telephoto factor It's not even necessarily related to the format, as acceptable CoC on digital will be determined primarily by sensor site size, not sensor size. -Adam Jens Bladt wrote: > ...CoC is a relative term - set seperately for each format, depending on how > much you must enlarge in order to see the image at a proper size. > I my world a smaller image (APS-size) should be enlarged more in order to > produce an acceptable, final image. > This should result in poorer overall sharpness. Why should this be regarded > as more DOF?? > > Since the image is cropped, the DOF in the final picture SEEMS to be > "better", since you most likely have croped away the unsharp edges. Still > the remaining image is the same as the center part of the 35mm frame. IMO > DOF does not change, just because you record the image on a sensor in stead > of a film. > > Another reason why DOF seem to be "better" in digital recorded images (small > sensors), is because we use shorter focal lengths in order to maintain the > same FOV. This will cause larger DOF in the final image. But this is > comparing two intirely differnt images, and this is NOT the subject here. > The same lens at a given aperture still produces exactly the same image - > althoug croped. > > Regards > Jens Bladt > http://www.jensbladt.dk > > -----Oprindelig meddelelse----- > Fra: Mishka [mailto:[EMAIL PROTECTED] > Sendt: 24. marts 2006 04:19 > Til: pentax-discuss@pdml.net > Emne: Re: crop factor vs. telephoto factor > > > DOF != CoC > > best, > mishka > > >>DOF doesn't changs either. DOF is dertemined by aperture and focal length. >>Nothing else. > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.385 / Virus Database: 268.3.0/290 - Release Date: 03/23/2006 > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.385 / Virus Database: 268.3.0/290 - Release Date: 03/23/2006 -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.3.0/290 - Release Date: 03/23/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.3.0/290 - Release Date: 03/23/2006
