Color shifts along sides of image with C Biogon

[kennylovrin]

Hey guys

I have a 35mm C Biogon that I bought used - really happy with it overall.
However, when I got the M9 I looked into what lens coding to use, but it seemed from reading online that one wasn't really needed.

However, I get some color shifts with this lens that I don't know if it is a sign of something wrong with the lens, or if it needs to be coded, or even accepted and adjusted in post.

Anyway, the shifts I have aren't really in the corners like a vignette would be, but rather along the full sides of the shot. It looks very consistent as well.

If I shoot in landscape, the left side of the frame shifts towards magenta from top to bottom, while the right shifts from green.

If I shoot in portrait then for some strange reason the color shifts are reversed (green on left, magenta on right).

The color shifts looks like magenta and green from CA, I mean it's the same kind of tone/tint. This kind of leads me to believe that the lens is in fact not perfectly aligned?

Any ideas regarding this?

Thanks!

Kenny

 

[kennylovrin]

Going through todays shots I just found one where the problem is very easy to see:

This example is slightly worse than what is usually visible as this image is quite uniform in color, but still, any ideas what I am dealing with here? 🙂

 

[FrozenInTime]

21mm or 35mm C Biogon ?

The 21mm version has obvious gren/maganta edge color shift - I normally crop it to square on the M9 in order to avoid shifts.
I don't think I've used the 35mm C-Biogon on my M9 yet.
There is a Adobe DNG flat field plug in that should help - but not tried it yet. http://labs.adobe.com/technologies/lightroomplugins/

 

[kennylovrin]

Oh sorry, it's the 35mm.

I might give corner fix a go as well, but I wanted to ask if others with this lens has the same problem or if mine is off.

 

[jaapv]

Yes, the camera can produce the socalled Italian Flag syndrome with non-Leica lenses. Often coding as an equivalent Leica lens can help. Otherwise Capture One has an LCC profile option that provides an easy one-click correction.