Purple Fringing

[highlandscenics]

I have this issue with purple fringing on some of my shots in contrasty locations. Especially if the subject is trees.
I willl give you a good example. Today I was at a favourite location of mine, Fairy Glen at Rosemarkie in the Highlands of Scotland. I was taking a shot of a bridge with the fast flowing river beneath it and a waterfall and birch trees in the background. It was a part cloudy day but the light was quite strong coming from the background. I was using a ND Filter and my exposure was 6 secs at f11. When I looked at the shot at 100% there was purple fringing along the hand rails of the bridge and on some of the tre branches.

What would be the best solution to prevent this in future shoots in similar conditions? I use the fuji finepix s200 exr and not a true SLR so any set-up ideas will be most welcome...I am still learning so what better place to ask than here with the pro's

[Forseti]

Originally Posted by highlandscenics

What would be the best solution to prevent this in future shoots in similar conditions?

And if you ever find out please let me know. Seriously though, this does happen from time to time along the bounderies of high contrast, even more so will smaller cameras, and is something that one has to accept. However, not all is lost because it's one of those things that can generally easily be removed in image editing applications.

I occasionly get the same with my Fuji S8x18 - From what I have gleaned the fringing is due to Chromatic Aberration - apparently it's more likely to occur with a wide angle lens - Suggesting that by reducing the angle the fringing effects may be reduced.

This link may also be helpful - http://digital-photography-school.co...n-in-photoshop

[chris-p]

Yes, it's chromatic aberration. The purple type is longitudinal aberration (or "axial colour") is caused by the inability of a lens to focus different colors in the same focal plane.

The image below shows a nasty example of it using a Canon EF 85mm f/1.2 L wide open on an EOS 5D.



You can also get transverse colour fringing which is often purple and green



This happens partly because the eye, and therefore auto focus systems, are more sensitive to green than other colours. The AF system tends to focus the "green image" accurately and if there is enough distorion of the light path through the lens (which is why this can be more common in wide angle lenses) this can effectively alter the focal length of the red and blue "images" hence you see a slighly off centre colour "fringe".

This is explained much better than I can by this website which is where I pinched these images from (so thanks to them!)

[highlandscenics]

Ahh I see now ..thanks. I must admit tho I do use my editing software to remove it, but I thought i best find out if it was something I was doing wrong.

[andreasphotography]

I seem to find this a major problem with the Sigma 18-200mm which i bought to replace my broken Nikon 18-200mm, I had never had a problem with Sigma lenses until now and the fringing is a complete nightmare so much so that i really can not use the lens for any thing other then snap shots

why would one lens be more prone to this then another lens ??

[matt wilson]

Probably simply down to the lens design and whether on not posh glass with coatings is used.I get it worst on the 18 to 200 Canon zoom.Vey noticable in gigh contrast e'g backlit tree branches.

[chris-p]

This is always going to be an issue with 18-200 type superzooms. It's down to they way they work and the inherent compromise in a zoom lens. The more focal length they try to cover the more compromise you have to build in.