Strange effect using 5D3 and 16-35 f/2.8L II

[bjd]

Hi,
just wondering about how this happened?

See the strange effect that the leaves have in the middle where the blue sky is the background, like chromatic aberation, but in light Blue I wasn't shooting into the sun, but it was a very bright day, taken late afternoon.

I couldn't get rid of it in LR due to parts of the sky having the same Blue colour.



Cheers Brian

 

[sulla]

I don't see it at this resolution of 1920x1080 px.
Can you post a 100% crop with these dimensions?

 

[bjd]

I don't see it at this resolution of 1920x1080 px.
Can you post a 100% crop with these dimensions?

Sure, BTW I see the blue fringing in LR and in the image shown on the website.

 

[sulla]

Ah, now I can see what you mean:
I guess it's the well known "purple fringing", a special, axial type of chromatic aberration effect that causes colour fringes - mostly purple - when a huge brightness contrast occurs on a very small scale, such as dark leaves before a bright sky, or at stage photography, e.g., more visible with digital sensors than with film.

http://en.wikipedia.org/wiki/Purple_fringing

The effect is usually much more prominent in medium telephoto lenses, 85mm lenses seem to be plagued the most.
I've seen it in Canon's own 85mm lenses, in Sigma's lenses as well as some very very good Leica glass.

I guess there are only very hard ways to remove it IN POST, though. In photoshop you could try to resize the red colour channel of the image...
It can be avoided - or mitigated - using a UV filter during shooting, however.

 

[sulla]

3 things to do during shooting:

• Avoid shooting with a wide-open lens in high contrast scenes.
• Avoid overexposing highlights (e.g. specular reflections and bright sky behind dark objects).
• Shoot with a Haze-2A or other strong UV-cut filter.

You might have done all 3 things wrong simulataneously in this image...

 

[bjd]

Ah, now I can see what you mean:
I guess it's the well known "purple fringing", a special, axial type of chromatic aberration effect that causes colour fringes - mostly purple - when a huge brightness contrast occurs on a very small scale, such as dark leaves before a bright sky, or at stage photography, e.g., more visible with digital sensors than with film.

http://en.wikipedia.org/wiki/Purple_fringing

The effect is usually much more prominent in medium telephoto lenses, 85mm lenses seem to be plagued the most.
I've seen it in Canon's own 85mm lenses, in Sigma's lenses as well as some very very good Leica glass.

I guess there are only very hard ways to remove it IN POST, though. In photoshop you could try to resize the red colour channel of the image...
It can be avoided - or mitigated - using a UV filter during shooting, however.

Hi, so it is just the same fringing, but in blue. And I guess the contrast was pretty intense. First time I have
seen it in Blue though, I have seen purple pretty often on this lens, oh and I did have a good UV filter on.

Thanks for the explanation.

Cheers Brian

 

[sulla]

I think so. When you spread out the purple colours over a larger area, like with many many small branches of the tree, then I guess a sharper blue remainder is all that is left from a branch.

 

[bjd]

• 3 things to do during shooting:
  

  • Avoid shooting with a wide-open lens in high contrast scenes.
  • Avoid overexposing highlights (e.g. specular reflections and bright sky behind dark objects).
  • Shoot with a Haze-2A or other strong UV-cut filter.

  You might have done all 3 things wrong simulataneously in this image...

  • Avoid shooting with a wide-open lens in high contrast scenes.
  Especially set to 4.0 instead of 2.8. Trying to keep away from using the extremes of this lens.
  • Avoid overexposing highlights (e.g. specular reflections and bright sky behind dark objects).
  I have lately been trying to conciously ETTR more, as I am not happy with the sensor noise the 5D3 produces.
  The histogram says the bright areas were not overexposed, but I was way to the right. Obviously its not a scene with a lot of dark areas, so I guess it would not be so important here. I'll take this in mind next time there is a lot of contrast.
  • Shoot with a Haze-2A or other strong UV-cut filter.
  Did have one.

>>You might have done all 3 things wrong simulataneously in this image...
That happens with me :-[


Thanks for the tips.

Cheers Brian