Cyan shift

[jrc]

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I can't figure out how to delete this -- there's already a thread on this that I missed. -- JC

 

 

If the cyan shift is corrected by the lens coding, that means essentially that a profile is being applied. So it would seem to me that the cyan shift can be treated like a species of vignetting, relatively easily corrected in software.

 

So couldn't Zeiss and CV, failing all else, just provide a plug-in for C1 LE, that would simply correct the cyan problem for however many lenses they wanted to correct? You're gonna need some program to extract the file from the memory card, so it's not going to be too inconvenient to apply the profile at that time...

 

I mean, Jamie estimated that he did ten hours of work to provide a C1 plug-in that made a huge diffference with the much more intractable magenta problem. How hard could this be for CV and Zeiss, where they would have progammers to work on it fulltime?

 

Or have I just stuck my head where the sun don't shine?

 

JC

[marknorton]

The problem, John, as was pointed out to me, is that by the time the program gets hold of the data, it's already been compressed to 8 bit so it's better to apply correction before compressing it, in camera.

 

The whole cyan and third party lens issue is strengthening the case for an option where raw means raw - uncompressed data out to the card. 20Mb DNG + 10Mb JPEG if you want it.

 

Once you have got this, the correction can be done by third party plug ins - including if they so chose - plug ins from Zeiss and CV for "their" lenses.

 

What we don't know is how easy the cyan correction is to apply, how specific to the lens it is, how specific it is to shooting aperture and the actual filter used and how well it works in camera. If JPEG counts for anything, it's got to be pretty darn good in camera when a coded lens is used. Otherwise, we might as well give up and use 20Mb DNG all the time.