[quote name='Brightcolours' timestamp='1280147057' post='1315']
CA can be an exception, depending on which colour(s) are the offending one, and the method of CA "correction".
I am not totally sure, but to me (having looked at samples) it seems that for instance Nikon does not correct CA in-camera (shooting JPEG) "correctly". It seems to filter out coloured edges. Again, I can be wrong in my perception.
La CA is basically one colour of light (or more) bending more (or less) through the optical system than the other colours. This means that if for instance the red colour is bending less, the projected red image is smaller on the captured image than the projected green and blue images.
Two ways to correct LaCA:
Of course, lower CA in lenses is by far preferable.
[/quote]
LoCa is actually also completely correctable in PP without any loss of detail, sharpness, or colour. However, that is a rather long-winded and convoluted process, where specific colour channels or even parts thereof are treated for correction, and with lots of masking layers involved. I did read a write-up on this half a year or so ago.
If I can find that article again, I'll post the link here.
I guess that that is method #3 <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
Kind regards, Wim
CA can be an exception, depending on which colour(s) are the offending one, and the method of CA "correction".
I am not totally sure, but to me (having looked at samples) it seems that for instance Nikon does not correct CA in-camera (shooting JPEG) "correctly". It seems to filter out coloured edges. Again, I can be wrong in my perception.
La CA is basically one colour of light (or more) bending more (or less) through the optical system than the other colours. This means that if for instance the red colour is bending less, the projected red image is smaller on the captured image than the projected green and blue images.
Two ways to correct LaCA:
- Filtering colour edges. This indeed does not fix, nor bring back what was lost. The muddy fuzziness brought on by the CA remains.
- Shrinking or expanding the "offending" colour channel. This will bring the image of that channel in line with the rest. This will get rid of the coloured edges on contrasty areas, and it will get rid of the muddy fuzziness. This method does fix what was wrong, and you gain sharpness and contrast.
Of course, lower CA in lenses is by far preferable.
[/quote]
LoCa is actually also completely correctable in PP without any loss of detail, sharpness, or colour. However, that is a rather long-winded and convoluted process, where specific colour channels or even parts thereof are treated for correction, and with lots of masking layers involved. I did read a write-up on this half a year or so ago.
If I can find that article again, I'll post the link here.
I guess that that is method #3 <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....