Originally posted by Kunzite Of course, I knew about Pentax pursuing actual image quality rather than test results. But now I wonder, what if Pentax wasn't uniformly slightly "worse" than the competition, if there are other factors why the numbers weren't as high (or low)?
We know what we're losing with the high CA numbers, we don't know if there is something else we might be gaining. The last example of CA I posted the CA was only visible in one image of the 8 or so keepers I got that day.
CA image...
No visible CA
Using the same set up positioning etc. I see very different CA, just from changing the angle of sun to subject a few degrees or a slight rotation of the camera on the tripod.
You can obsess about CA, you don't have to. Most of the time I don't even bother correcting it.
The best conditions for producing CA would be high contrast good lighting. Or in other words , a test chart. I'm not sure how relevant that is to everyday shooting.
Even in high contrast situations.
Someone needs to talk to an optical engineer to see how they see it.
What we need to do here is ship the same lens to someone with a Sony and Pentax and Nikon adapters, and test the different incarnations on the same camera, then the Pentax lens on the Sony Camera and k-1. We have way too many variables to know what's going on. Are the sensors used by Pentax more prone to reproducing CA, is it some component of the Pentax implementation of the design? Was the same lens used for both of the tests, and could that lens be defective? We don't know anything.
But based on my experience with my own lenses, sometimes they produce CA , sometimes they don't. There are parameters I've never bothered to define. So, I'm completely unwilling to commit to any kind of explanation, beyond let's keep an eye on it until we get a more thorough understanding of CA, especially with regards to it's prevalence in the shooting conditions most of us shoot in every day.