Originally posted by Alex00 We'll let's say I'm looking at wide angle lens, between Pentax 12-24 and sigma 10-20. Pentax shows high CA low distortion where as Sigma shows Low CA high distortion. Both seems to have good IQ in the center.
Originally posted by Alex00 Again, This thread is not about Pentax or sigma. It's about CA vs Distortions and which is easier to correct. It would be great if we can stick to this subject. It's irrelevant to threads i posted before.
Well, now I'm really lost!
It seems like Jeweltrail is just trying to say: discuss this all in one place. If these are the lenses you are considering, discuss all the points together, pluses, minuses, CA, distortion, etc.
The reviews are pretty decent on both of these. IMHO, too much time can be spent on the angels on the head of the pin, and not enough on using the pins to put something together; i.e., discussing the lenses to death instead of using them (or one or the other) in real life.
That given, I'd buy the lens with the less CA given the choice.
But, not every lens has much or any CA at every focal length (if a zoom) or at every aperture or in every light angle. Sometimes lighting conditions are very much to blame. So, again, life is a compromise. Lenses vary in distortion and CA over various settings/uses.
A car can have great handling but be hell to ride in or be soft riding and have excessive roll in a curve.
Life's like that with lots of choices. There often is no technically perfect answer.