Blue Line.

I shoot with Sony a7R4 and Sony 100-400 f 4.5-5.6 +1.4 TC.
When the subject (bird and dark green foliage) is surrounded by blue sky in the picture, then there is a visible blue line along the dark area of the bird and the vegetation.
I shoot RAW and convert it into TIFF file in DXO Photo Lab 4. The blue line gets more pronounced and bothersome.
It can be dealt with in Photoshop CS5 but it a time consuming tedious work.
Anything can be done to prevent the blue line along the dark areas to be formed?
Thanks,
Karl.

Hello Karl. when you do your conversions there should be a " defringe" setting in the lens correction area that you can adjust to remove the defringing you are getting, the blue line thing you are experiencing.

I know nothing of the quality of the sony equipment you are using but adding the TC may be enhancing the blue line effect and/or it could be your lens could need adjusting for critical sharpness as it is a common symptom of lower quality lens with TC's or lens that need adjusting to achieve proper sharpness.

First step on your existing images is to apply some defringing during conversion to your tiff files.

The lens is a Sony professional GM, not a "lower quality lens".  Also, this is a mirrorless lens on a mirrorless camera so the issue of adujusting focus is also moot.  I use the Sony 100-400 on my A7RIV and have never seen the issue of chromatic aberration fringing.  I don't have, or use the TC so I can't comment on that.  Unfortunately, I use Adobe software all the way through, but as Kim says, I have "remove chromatic aberration" checked and that may be eliminating what you are seeing?

It should be possible to remove chromatic aberration when you do the RAW conversion in your software.

can you post an example Karl? Does it appear if you use other raw conversion software? Some converters are quite aggressive with some adjustments and worsen or create artifacts.

Scott Fairbairn wrote:can you post an example Karl? Does it appear if you use other raw conversion software? Some converters are quite aggressive with some adjustments and worsen or create artifacts.

Thanks, Scott.
I'll try to include an example. The dark blue line is at the dark belly of the bird.
k

This may also happen with too much sharpening and/or noise removal.

This may also happen with too much saturation, sharpening and/or noise removal.

Edit: What I also see is a light blue halo around the bird.

It may be my monitor, but I don't see anything there. I would try a different Raw converter and also check Stephens suggestions.

Karl, I can see it and it does look like chromatic aberration. So yes you should be able to remove it in your raw converter. As suggested above it can be exacerbated by overprocessing in some functions but I think your image does not show that on my monitor.
I am thinking it is the TC that is amplifying the chromatic aberration.

If you turn on that feature in your raw converter I think it will fix your problem.

Thank you all. I tried a few RAW converters. The proprietary Sony program does remove the blue chromatic aberration but not the noise. In DXO Photo Lb Elite 4 on the other hand everything was turned on but then blue line remained. I still like to use it as it does an excellent job removing noise automatically. I downloaded the stand alone DXO Pure RAW just now. I will modify my workflow for the time being, and combine Pure Raw and Sony's Imaging Edge.
and see how it works out. Meanwhile I tested the lens with and without the TC. Also tested the camera with two lenses and the two lenses with a7R4 and a7R3.
Results are all the same. The blue line is present in the original unprocessed Raw file all the time when you have a darker surface against blue sky.
Well, I read that the high resolution cameras will bring out all the possible faults.

Are you shooting electronic front curtain shutter?

Joe

Karl, have you tried Capture One? I find Capture one does a great job with raw files.

Scott Fairbairn wrote:Karl, have you tried Capture One? I find Capture one does a great job with raw files.

I tried for the free version of Capture One for Fujifilm when I had a Fujifilm camera and I did not find it very user friendly.
The full version is probably much better but expensive.
I tried other RAW converter, Adobe DNG that is, and it does a very bad job.
Imaging Edge from Sony removes the fringing but leaves all the noise behind. I Tried to combine the stand alone
DXO Pure RAW for noise, then using Imaging Edge. So far I failed to make them work together.
Thanks for the help, Scott.