Chromatic Aberration and Defringing

[Jimmsp]

I've been playing with the CA correction and defringing tools in LR RC2.
A couple of questions come to my mind.

1. Why would I not ever check the box for remove CA ? Shouldn't it always be on?

2. While I can see the result (in a few cases) of defringing, it isn't obvious to me how I optimize it. Can anyone point me to a good reference?
I've tried a few searches and haven't really found anything that I like.


Thanks,

Jim

 

[Jim Wilde]

Have you looked at Eric Chan's article on the Lightroom Journal piece announcing the RC2? See it here.

As to why the CA removal isn't turned on by default, I assume that it's processor intensive and so should only be turned on when CA is present.....but I'm only guessing.

 

[Jimmsp]

Jim,
Thanks for the Eric reference.
I missed this. Though on a first pass, it looks like I have a lot of learning and playing to do.

Re CA on - I'm running a decent processor. I may always turn it on; I'll have to see what the speed impact is.

Jim

 

[Victoria Bampton]

Yep, you're quite right about the fact it's processor intensive, which is why it's not on by default. If you don't find it to be a problem, you could update your defaults to automatically apply it.

 

[Jimmsp]

Actually, in my recent tests, I find the overall performance is highly dependent on the number of photos in the folder that I load.
The more files loaded at the same time, the slower the performance is; especially with variable sliders for noise and sharpening.
I have tended to avoid some of these by starting from a number of noise presets that I generated on a test pattern.

In general, the best advice, often given here, is to adjust the variables in the order presented by LR.
This means saving CA until the end -- especially on a large number of photos.

I forget that LR is first a data base, then a file processor.