Chromatic Aberration...

[JeffieLove]

How do you fix it in post???

I can google what causes it, but if anyone wants to include a more lamens term version of what causes CA, I'd appreciate it too LOL

 

[JeffieLove]

Here's the SOOC. I'm sure you can pick up on where the CA is... But just in case, it's around the edge of the tree to the left of his head

This was shot with my 85mm lens... Settings were: ISO100, f/2, 1/1250s

 

[Bitter Jeweler]

Photoshop and lightroom have tools to fix it. With sliders and everything.


...and it's "layman's". :greenpbl:

 

[dxqcanada]

CA is caused by light passing through the glass.
Each wavelength of light (red, yellow ... blue, violet) is focused at slightly different points by the lens. This causes images to look out of focus or the color fringing on high contrast edges.
Using various methods, the lens manufacturer will attempt to correct for that.
Lenses with very low CA have very high levels of correction and cost more to manufacture.

Some Applications such as Adobe CS5 or Lightroom 3 have built in algorithms to correct for it (I am not sure about other Apps).

 

[JeffieLove]

I heart you

Thanks

 

[Bitter Jeweler]

In Photoshop I think it's under Lens Distortion (don't have it here) and in lightroom, it's in developing way down passed sharpening and noise reduction, if I remember correctly.

 

[JeffieLove]

Gonna have to see what I can do with Photoshop... LR isn't taking it out... I can get it out of the tree spot, but then I end up with a green halo all around his head... UGH!!!

 

[dxqcanada]

In Photoshop I think it's under Lens Distortion (don't have it here)...

With CS5, it is under Filter -> Lens Correction Shift+Ctrl+R

 

[Bitter Jeweler]

Thank you!

It's hard to remember stuff when it's not in front of you.

Like not remembering a phone number until you are dialing it.

 

[JeffieLove]

Phew! Took a little bit of cloning and some hue/saturation adjustment layers but I got it taken care of...

After getting the photo into PS I noticed some magenta in his hair tooo...

And I was able to find information on how to prevent it

Thanks for the help friendies

 

[Bitter Jeweler]

How do you prevent it?
Inquiring minds want to know!

 

[dxqcanada]

It's hard to remember stuff when it's not in front of you.

Yup, the only reason why I answered, was that it (CS5) was right in front of me.

 

[KmH]

ACR has CA correction tools in the Lens Correction panel.

 

[Robin Usagani]

or just select that area (no need to be accurate) and do hue adjuments. For example reduce magenta or blue or whatever color the CA is.

 

[Dao]

The software that shipped with the Canon camera has tool to correct the chromatic aberration with RAW files. If you use a compatible lens (most likely lens that made by Canon), it can correct it automatically.

1. Run Canon Digital Photo Professional (If you use a older version, you may need to download the updated version from Canon).
2. Open the RAW image in Edit Window.
3. If you are using MS Windows, press CTRL-T or click "View" then choose "Tool Palette".
4. In the Tool Palette, click the "NR/Lens/ALO" Tab.
5. In Lens aberration correction section, click the "Tune..." button.
6. I think you should know what to do after that.