Chromatic abberration ?

Seajay

Seajay

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Cathy
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I was taking some images at a local gym with another photographer who set up the lighting. A lot of my images have this chromatic aberration going on.
Is this because my lens and settings were wrong or did I need more light? I used my Canon 6D with a Sigma 35 art settings were ISO 200 f7.1 125
I would like to do this again but need some advice on how to prevent this. For now I am painting the black backgrounds out to be black and the image looks very grainy but that is ok.
Hope you can help :)example.jpg
 
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To my knowledge at least (I'm sure someone will correct me if it is wrong) chromatic aberration is a by product of the lens you are using as opposed to the settings you selected. If you shot in RAW and are using something like Lightroom or Photoshop (can use adobe camera raw here), you can remove CA by clicking a check box and it does it very well. I've never tried to remove it from a JPEG but I'd assume it would work the same.

EDIT - Just seen the photo you uploaded, that looks like colour noise to me, not CA.
 
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That's not CA it's noise. Are you sure you were at ISO 200? That seems very noisy indeed for such a low ISO. CA is usually seen as purple fringing along high contrast edges, and as said above it's usually a one click process in Lightroom to remove it
 
Had a look in photoshop and can not see even a trace of Chromatic aberration.
However the Colour noise is horrendous when the image is lightened with curves, and shows huge irregular patches of reddish granularity.
I fail to see why the image is so noisy with your exposure of ISO 200 f7.1 125
Of course the black background is heavily under exposed and one would expect to see noise in those conditions but even the chaps forehead is far noisier than one might expect at iso 200.
I do not care for the way the camera is handling noise and would expect better from a FF camera even of that generation.
I would expect more recent cameras even with a crop sensor to do rather better.
The noise is more like I might expect at 2000 rather than 200.
 
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Terrywoodenpic said:
I would expect more recent cameras even with a crop sensor to do rather better.
The noise is more like I might expect at 2000 rather than 200.
Click to expand...


I've literally just shot a photo using my 80D inside a windowless meeting room at work at ISO2500 and it's not as noisy as the OPs image
 
Thank you everyone :) I agree with you all the noise is really bad in most of them and yes the settings are right.
They all looked good on back of camera but not in Raw in photoshop. The only thing I thought was that the lights were camera flashes and that we were sharing his controller for his camera to work them and he has a Nikon ? This is another example with different settings and much the same.
 

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Seajay said:
Thank you everyone :) I agree with you all the noise is really bad in most of them and yes the settings are right.
They all looked good on back of camera but not in Raw in photoshop. The only thing I thought was that the lights were camera flashes and that we were sharing his controller for his camera to work them and he has a Nikon ? This is another example with different settings and much the same.
Click to expand...

I can not see this as being anything to do with the lighting.
The Histogram of Example2 shows a normal distribution of tone for that subject and exactly what one might expect.
You would expect there to be noise artifacts in the almost totally black areas. but in the normal way black areas are handled by the camera firmware to minimise them.
In this case the noise extends even to the better illuminated parts of the image.
Example 2 is sharp but grainy. though we do not know what magnification the clips represent, I am supposing that they are at 100%
Can you put up one showing the whole of the image as it might be that this section is seriously under exposed as that seem the most likely cause.

You clearly need to do some more experimenting in that lighting, so as to give more clues as to what is going on.
 
Have you done any Shadow recovery in photoshop? Pulling the shadows too high on an already underexposed image causes that sort of noise to appear even on low ISOs. To me at least the histogram looks under exposed...
 
I knew you would help me find the answer and Terry you are right.
I had adjusted exposure for one and sync to the others did think they looked a little darker than my usual but not to the extent they are. They are all underexposed too much so I guess that's the problem solved. They just seemed to look ok in camera but next time I am putting up my histogram lol
Thanks all :)
 

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Seajay said:
I knew you would help me find the answer and Terry you are right.
I had adjusted exposure for one and sync to the others did think they looked a little darker than my usual but not to the extent they are. They are all underexposed too much so I guess that's the problem solved. They just seemed to look ok in camera but next time I am putting up my histogram lol
Thanks all :)
Click to expand...

Is the LCD brightness high on your camera? That can easily fool you in to thinking the photo is exposed correctly when in fact it is under exposed.
 
I'm going to guess that you set iso 200 but have your 6D configured for 'safety shift' using iso.....the iso will be ramped up if the exposure would have been incorrect using your chosen aperture and shutter speed.

Bob
 
Andrew Benbow said:
Is the LCD brightness high on your camera? That can easily fool you in to thinking the photo is exposed correctly when in fact it is under exposed.
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Yes Andrew it was so another thing to remember .Thank you for bringing my attention to that as it is something I would have not even thought about,
 
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Canon Bob said:
I'm going to guess that you set iso 200 but have your 6D configured for 'safety shift' using iso.....the iso will be ramped up if the exposure would have been incorrect using your chosen aperture and shutter speed.

Bob
Click to expand...
Bob I will need to check that one as I am not sure .Good thing is the images and look ok after a little work they will be fine if they just want them for social media and small prints lol
 
Seajay said:
I knew you would help me find the answer and Terry you are right.
I had adjusted exposure for one and sync to the others did think they looked a little darker than my usual but not to the extent they are. They are all underexposed too much so I guess that's the problem solved. They just seemed to look ok in camera but next time I am putting up my histogram lol
Thanks all :)
Click to expand...

Glad you have found the answer.
Excess noise is almost always lack of light reaching the sensor.
 
As others have said, the above is noise, no chromatic aberration. You can remove it somewhat by removing colour definition, but it can result in losing detail. In the example above, it would likely help, since there doesn't appear to be anything behind the subject texture wise :)
 
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