Weird color around white lines?

[patty_garson]

<p>Hello,<br>

If someone could educate me about what's going on here, I'd appreciate it. I just took a few goof-off first shots with my newly purchased Tokina 11-16mm lens and noticed these lines of color running along the white stripe on the road and the white post in the field. Here's a crop of one image to show what I'm talking about- shot at 11mm, 1/200, f11, ISO 100 on a Rebel T1i:<br>

http:/i36.tinypic.com/308gx7s.jpg<p>

It's in every shot that has any kind of strong white line. I took a few shots with a Canon 24-105L lens to compare, and the same thing shows up a bit, but much less intensely than it does in the Tokina images (could have just been a change in light since it was 20-30 minutes later in late afternoon). Could it be because I wasn't using a hood or filter of any kind and the strong light created some kind of glare? Anything I could have done to avoid this? I'm hoping it's not a problem with the lens. From the looks of the box it arrived in, it had a rough time during shipping so I'm being hyper-sensitive to potential problems...</p>

<p>Just curious if anyone has any insight to share. I'm definitely a beginner and clueless about many things. Thank you! :)</p>

[peter_daalder]

<p>Read the <strong>Optics</strong> paragraph of <a href="../equipment/tokina/11-16/" target="blank">this Tokina review</a> and look for the sentence that mentions<em> “fix-able” chromatic aberration.</em><br /> This can easily be corrected during the post processing of your images.<em><br /></em></p>

[patty_garson]

<p>Thank you! Chromatic aberration... that's a pretty simple explanation. Sorry, probably could have figured that out with a bit more research before posting. Thanks again!</p>

 

[tommyinca]

<p>The shorter the lens' focal length, the worst these type of color convergent problems are. It is also not fair to compare a 11-16 to a 24-xx zoom in this area. Here is how your image could look corrected. For better result, shoot raw and correct CA during the raw to JPEG conversion. </p><div></div>

[leighb]

<p>When white light passes through glass at an angle, the different colors are refracted (bent) by different amounts. That's how a prism works, and it's true for all glasses.</p>

<p>The severity of chromatic aberration in a camera lens varies dramatically with the type (Planar, Tessar, etc). Some types are better in this respect than others. It's one of several aberrations and degradations that must be traded off one against another when designing the lens in the first place.</p>

<p>To a lesser extent, the quality of the product from a particular manufacturer may be better or worse than the same type from another maker.</p>

<p>- Leigh</p>

[andrewg_ny]

<p>One other factor is that more recent D-SLRs can correct some of this in-camera, but likely only for the manufacturer's own lenses, likely the more recent/popular ones, excluding some older models. Pretty sure the T1i has vignetting/falloff correction, not sure about CA correction.</p>

<p>The third-party lenses probably cannot be done automatically in-camera.</p>

[patty_garson]

<p>Thank you all so much. It's making much better sense now. Appreciate the info!</p>