Green and red fringing

[homeward]

I'm starting to get (or, more likely, starting to notice that I'm getting...) green and red fringing on some of my shots -- especially on the edges of white areas, and on the periphery of pictures; and I'm worried that it might be my camera, rather than my lenses (which is what the research I've done on the web so far would actually suggest -- so I'm probably just being paranoid; and should probably just accept that this is what happens unless one pays serious money for lenses...).

See here for an example (...look at the window-frames to the right of the photo).

I have a Nikon D200, and I've noticed the fringing using two lenses, so far: my Sigma 18-200mm f/3.5-6.3 DC and my Sigma 28-300mm f/3.5-6.3 DG Macro. Interestingly enough -- well, to me, anyway... -- is the fact that the shots that I've taken that prompted me to post this have all been taken on incredibly bright, sunny days, with lenses with quite a large zoom range....

I've yet to do more extensive testing; but I will go back and try some more lenses (e.g. my Tamron and Nikkor ones) in similar conditions, and then report back: but I just wondered if anyone here had any thoughts in the meantime....

Thanks for listening...!

[ghsmith178613]

I'm starting to get (or, more likely, starting to notice that I'm getting...) green and red fringing on some of my shots -- especially on the edges of white areas, and on the periphery of pictures; and I'm worried that it might be my camera, rather than my lenses (which is what the research I've done on the web so far would actually suggest -- so I'm probably just being paranoid; and should probably just accept that this is what happens unless one pays serious money for lenses...).

are you shooting RAW? are you using PSCS2/3?
as much as i hate the photoshop crutch, there is a lens aberation adjustment in the RAW processing tab. http://www.adobeforums.com/cgi-bin/webx?14@@.3bb6a85c.3bc08253/0
of course, there is no substitute for quality glass or a full sample sensor. if this band-aid doesn't work, well...

[homeward]

Cheers...! I'm shooting both RAW and high-quality JPEG: but the fringing's there on both formats....

I use PS Elements 4 at the moment, using the cut-down RAW importer that comes with it; and which doesn't have the lens/aberration correction stuff that I know the full one does.

Looks like I shall have to cross-check with my other lenses; and go back to some archive shots to see if it's always been happening, but I just haven't noticed before.... And then, I suppose, it's time to upgrade to a full copy of Photoshop...!?!

Thanks for your help...

[homeward]

After messing around with the Camera Raw import plug-in that comes with Photoshop Elements 4.0 on the Mac (version 3.3 (52)), I've discovered that a quick and dirty way to get rid of the fringing is to change the "Color Noise Reduction" setting -- on the "Detail" tab -- from its default setting of 25 all the way up to 100.

You may have to mess around with levels and saturation a little to bring some of the life back: but it seems to do the trick...!

Hope this helps someone else...!

[andrys]

Cheers...! I'm shooting both RAW and high-quality JPEG: but the fringing's there on both formats....

I use PS Elements 4 at the moment, using the cut-down RAW importer that comes with it; and which doesn't have the lens/aberration correction stuff that I know the full one does.

Looks like I shall have to cross-check with my other lenses; and go back to some archive shots to see if it's always been happening, but I just haven't noticed before.... And then, I suppose, it's time to upgrade to a full copy of Photoshop...!?!

Thanks for your help...

Try PTLens at http://epaperpress.com/ptlens/index.html

It's superb, for easy fixing of distortion and chromatic aberration
(and see-as-you-slide rotation). Free trial available. Works
in Photoshop as a plug-in. Buy if you like. Best $15 I ever spent.

Don't miss the Examples page at
http://epaperpress.com/ptlens/example.html

If you have a Mac, however, they recommend Lensfix and provide
the link to it.

[dougj]

I agree with Andrys, PTLens is an excellent tool to correct several types of lens distortion and CA.

[jstuedle]

[/quote]of course, there is no substitute for quality glass or a full sample sensor. if this band-aid doesn't work, well...[/quote]

A little off topic, but a full frame sensor (full sample?) would only magnify the issue. The 1.5 or APS size sensor actually "sees" only the sweet spot of a full frame 35mm format lens. Because a photo site on the sensor can only accept light parallel to the lens axis, both fringing and vignetting can be more prevalent with full frame sensors. Film does not accept light in the same manner, it will expose with light from any angle. A 12 MP APS sensor can be sharper than a 12 MP full frame sensor for these reasons.

[steveprice]

Hi, all lenses are a compromise between various forms of abberation: the one you noticed is chromatic abberation. When light passes through a lens it is broken down into component colours, the problem then is to bring all those colours to focus at a given plane in the camera; not as easy as you might think. I used to worry about this kind of thing until I realised the time spent testing was much better spent taking pictures. The simpler the lens i.e. one focal length, the lesser the problem. Zooms, particularly zooms with extreme ranges add to the complexity of the lens configuration and therefore the problems are more difficult to resolve.

I cant see it in your picture. I dont think you have an exceptional problem. But I know what you mean. My Canon lenses have it. If I see it I correct it, if not, not. A good way to minimise it is in the Filter/Lens Distortion menu in Photoshop CS2 by using just a simple slider. The fact that Adobe added this option must tell you something!

Cheers.

Steve Price

PS I have a full frame Canon 5D.