Color Fringing on Shadow's Edge

[mark_mui]

<p>Can anybody explain why color fringing occurs on the shadow’s outer fall off area? <br />Camera: D3, iso 200, 135mm 1/200 f13. Lens: 70-200, light: Profoto D1 with large softbox. <br /><br />This happens often my shadow when I shoot against a white background with any of my lenses. Is this normal? I dont see this when I shoot with my assisstent's canon 5d.<br />Thank you for your input.<br />Mark<br /><img src="http://farm5.static.flickr.com/4017/4473477738_c4f9fee81b.jpg" alt="" width="500" height="356" /><br /><br />link to full size: <a href="http://farm5.static.flickr.com/4017/4473477738_b9cba34c5b_o.jpg">http://farm5.static.flickr.com/4017/4473477738_b9cba34c5b_o.jpg</a></p>

[Matt Laur]

<p>Those are JPG compression artifacts ("banding"/"posterization") - not a function of the lens. Are you shooting straight to JPGs, or working with RAW files? How are you creating the output file that you're actually seeing, above?</p>

[mark_mui]

<p>I shot this with Nikon Raw. These color bands are visible while viewing the raw nef in adobe Lightroom. No matter what profile settings I use to convert (ACR or Adobe profiles), they still appear.</p>

[Matt Laur]

<p>Do you see them when you use a different file viewer/utility (say, Nikon's free View NX) ?</p>

[umesh_bhayaraju]

<p>Yes, I too believe that it is an artifact of file compression/conversion algorithm. Just check the file size.</p>

[ilkka_nissila]

<p>To me it looks like the 'fringe' is formed by light scattered from the colored hat.</p>

[tom_mann1]

<p>Yes, it certainly looks like posterization, but this is a consequence of the bit depth not compression artifacts or the RAW converter. Specifically, JPG compression artifacts look blocky, not like bands. There was a recent discussion of this here: <a href="http://www.photo.net/digital-darkroom-forum/00Vl7k">http://www.photo.net/digital-darkroom-forum/00Vl7k</a></p>

<p>The bottom line is that even if an image starts out with 14 or 16 bpc, once you take the image down to 8 bpc, any featureless, low noise, low gradient areas will show banding if you look closely enough. The usual solution is break up the bands by introducing a tiny bit of random noise (ie, 1 level out of 256) at each pixel.</p>

<p>Tom M</p>

[elliot1]

<p>Have you tried opening the NEF file with NX or NX2? Is there more than one light source?</p>

[mark_sirota1]

<p>What version of Lightroom, and what profile are you using?</p>

<p>Adobe recently released betas of <a href="http://forums.adobe.com/thread/602274">new camera emulation profiles for the D3 and D700</a> which are designed to avoid hue shifts like these. They'll work in Lightroom 2.x, but try them in Lightroom 3 Beta 2 with Process Version 2010 for best effect.</p>

<p>In the meantime, I think you'll find the effect is minimized if you use Adobe Standard as your profile rather than the camera emulation profiles. Noise reduction can also sometimes play a part. Or, as others have suggested, other raw converters won't have this issue.</p>

[kohanmike]

<p>Haven't there been posts about not using to small an f stop because that will cause fringing and such, especially using older lenses without coatings?</p>

[mark_mui]

<p>Thanks for all the ideas. I've tried LR with standard and neutral profiles, both v1 and v2, NX2.0 and LR3 Beta. A comparison can be seen here: <br /><a href="

It seems NX is the best at removing the color banding.</p>

[Matt Laur]

<p>Just to be clear: what's really happening is that - in the way you're using all of the contenders, here - NX is the best at not <em>creating</em> the color banding.</p>

[mark_mui]

<p>Yes Matt, that is correct.</p>

[robert_k1]

<p>This does not look like the normal fringing from chromatic aberration. But have you tried this simple test in ACR?<br>

http://www.photos-of-the-year.com/articles/adobe-raw/</p>

[mark_mui]

<p>Thanks everyone for pointing me in the right direction. Based on your ideas and suggestions, I came a cross this photog that outlined the problem pretty well. Its quite clearly a raw conversion issue:<br>

<a href="http://ishootshows.com/2010/01/22/lightroom-3-vs-nikon-capture-nx-2/">http://ishootshows.com/2010/01/22/lightroom-3-vs-nikon-capture-nx-2/</a><br /><br />Todd replicated the banding issue with this photo:<br /><a href="http://farm5.static.flickr.com/4006/4294006529_9d05984536_o.jpg">http://farm5.static.flickr.com/4006/4294006529_9d05984536_o.jpg</a><br>

Adobe has beta profiles that are trying to emulate the NX converter:<br /><a href="http://ishootshows.com/2010/03/28/lightroom-3-improved-camera-profiles-highlight-rendering/">http://ishootshows.com/2010/03/28/lightroom-3-improved-camera-profiles-highlight-rendering/</a></p>