purple fringes ... is it the lens or the CCD? confused!

It was pointed out to me in another thread that CA and purple fringes are two different thing.

Have done some reading up on the net and realise that purple fringing is more a CCD issue where lights over-spill to neighbouring pixel cells.

is this correct?

if yes, then lens from different manufacturer should exhibit similar performance in terms of PF cause it is not a lens issue.

however, one often reads that some lens are really bad in PF while other is very well controlled ... the Sigma vs Tamron for 70-300 is one example.

So, i am a bit confused.

Are coating and APO glass correcting factors to PF ? or the "one is better than the other" comments are mostly subjective perception?

I've also seen articles suggesting that PF is more of a CCD than lens issue, but they don't make sense to me when PF is rarely a problem with some lenses but commonly a problem with others.

Also, well respeced reviewers mention PF (as well as CA) in direct relation to lenses.

Numerous comparison shots I've seen between the Tamron 70-300 LD Di and the Sigma equivalent provide clear ojective examples. The Tamron more often results in more purple fringing.

Even if PF is a type of CA (I didn't think so, but I'm not sure now), the practical point is that PF is more difficult to remove with software than common types of CA.

Yes the internet is confusing! You will find conflicting opinions and advice on every subject. I think you just have to read as much as you can (be bothered) and go with your gut instinct as to what is most likely to be correct, and ignore all that isn't relevant to you.

Hi,

"Yes the internet is confusing!"

This is because any Tom Dick or Harry can post any old nonsense on the WWW. The web is FULL of incorrect information...and yet so many people re-quote stuff from the web without kowing if it is correct or not, so the mis-information spreads...
cheers Steve

Wikepedia has a sensible article

http://en.wikipedia.org/wiki/Chromatic_aberration

CA is clearly a lens issue

PF seems to be a combination of sensor and lens design issues

Sea also

http://en.wikipedia.org/wiki/Purple_fringing