Is this chromatic aberration?

[codrus]

Looking at some pictures I took over the weekend, I noticed purple edges to the highlights in some of them. Is this chromatic aberration? I see them in this shot, particularly around the edge of the mirrors:

http://codrus.smugmug.com/gallery/6566164_6yd4E#417936212_zskT

Whereas this shot from a similar angle doesn't show them:

http://codrus.smugmug.com/gallery/6566164_6yd4E#417940508_RN4zP

Both are shot with my 50D, the first with the Canon 50mm f/1.8 II and the second with the EF-S 17-55 f/2.8. Is this just the $80 vs $1K lens price showing through, or is it related to the difference in aperture (both are wide open)?

thanks
--Ian

[LiquidAir]

Purple fringing is not the same as chromatic aberration, but it is a lens artifact. You were shooting at f/1.8 with the 50 which not going to give you the best quality that lens can deliver. If you are looking for sharpness, try stopping down to f/5.6.

[pyry]

Purple fringing is not the same as chromatic aberration, but it is a lens artifact. You were shooting at f/1.8 with the 50 which not going to give you the best quality that lens can deliver. If you are looking for sharpness, try stopping down to f/5.6.

Depends on what you mean by purple fringing, I think it's usually the lateral kind of chromatic aberration. However, in the particular shot mentioned above with the 50mm, the mirror is surrounded by flare.

In the same shot: take a look at the reflections of the sky on the side of the car. Behind the mirror they are fringed green, and further forward in purple. This is longitudinal CA - the colour of the fringe depends on the highlight being forward or behind the plane of focus.

This is what lateral CA (http://en.wikipedia.org/wiki/Image:Purple_fringing.jpg) looks like. The fringes either favour one side (or seem to, because the other side is too bright to show it) of a strong contrast or change colour from one side to the other.

And yes, the 17-55 is less prone to any of this than the 50mm.

[Tee Why]

It looks like CA to me as well.
The lens doesn't have that much but per slrgear's test, looks like there is a bit less of it when you stop down by f4.
Here is a link to the test.
http://www.slrgear.com/reviews/showproduct.php/product/150/cat/all

DPP and LR both have ways to reduce it as well in post processing.

[codrus]

Thanks folks. I hadn't actually noticed the green fringing in the background before, interesting. I don't really want to stop down and lose the blurred background.

As for postprocessing, I'm using Aperture. Any idea if there's a way to reduce it in there? I haven't seen it mentioned in what I've gone through on it so far (only started using it about a month ago).

thanks,
--Ian