Blue lines over the branches

[NimArt]

<p>Hi<br>

Actually I didn't know in which category should I post my question,<br>

I captured the photo as attachment ,in late afternoon with my Canon 7D and 70-200L f4 lense , F:4 @1/50 sec. ISO:160.<br>

Would someone please describe me what are those blue lines over all branches the photo when I crop it in 100%?<br>

I think its the reflection of the blue sky but how can I get rid of it with my camera, or maybe should I edit it in photoshop?</p>

<p>thank you in advance<br>

Nima</p>

[craigd]

<p>I don't see an attachment.</p>

<p>Blue or cyan lines around branches are sometimes seen when the branches are against the sky and sky is badly overexposed.</p>

<p>You might also try stopping down the lens a bit in case the effect has something to do with lens aberrations that are at their worst at maximum aperture, but the EF 70-200L f/4 lens is supposed to be excellent wide open, so I kind of doubt that's the problem. Still, easy enough to test.</p>

[bob_sunley]

<p>Well no photo at the moment, but 1/50 sec is a good way to get motion blur from the operator and/or the subject moving. Also it could be chromatic aberration made worse from movement. Your shutter speed should be at least 1/100 of a sec at 70mm and 1/200 at 200mm to minimize blur caused by camera movement.</p>

<p> </p>

[eric merrill]

<p>Sounds like chromatic aberation. Are you shooting RAW or jpeg? If RAW and using Adobe Camera Raw, there are settings to minimize this.</p>

[mukul_dube]

<p>Please search here, and on the Internet, for "purple fringing".</p>

[Alan Marcus]

<p>All lenses, regardless of make or model are plagued by a plight labeled aberrations. These are lens defects that cannot be completely eliminated. <br>

1. Spherical Aberration - A blurred image due to differences in the focal length central rays vs. rays that come from the edge of the lens.<br>

2. Coma - points of light should reproduce as tiny circles instead show up like a comma (circle with tail).<br>

3. Astigmatism - distortion caused when the curve of the lens is different horizontally vs. vertically.<br>

4. Curvature of field - focus at the center is different from the focus at the margins.<br>

5. Distortion - a. pincushion b. barrel -- the image of a square is distorted with bulging or curved- in sides.<br>

6. Chromatic Aberration - a. longitudinal - each color comes to a focus at a different distance from the lens. b. chromatic -- difference in magnification - each color image is different is size - a rainbow of color surrounds objects and is most notable as a purple fringe around objects against a mundane background.</p>

<p>The lens maker combines different types of glass with different shapes of lens in an attempt to correct these aberrations. The lens design becomes complex made up of groups of individual lens elements. A zoom lens design requires moving lenses and groups. It is far more difficult to correct a zoom and the cost of a well-corrected zoom is high. Aberrations are more pronounced when the lens is zoomed out. </p>

[NimArt]

<p>Thank you all of you and I'm really sorry about the photo, I sent it , but don't know why its not here, I do it again.<br>

Thank you<br>

Nima</p><div></div>

[mukul_dube]

<p>Nima, this is a small photo file and no detail is visible in it. At 100 per cent magnification, do you see something like the bird attached?</p><div></div>