Author Topic: purple fringe (Read 6674 times)

tierlakay · « **on:** July 30, 2008, 05:16 »

hello to all i have only recently joined here but been doing stock for about a year now, anyway i have just bought a new camera and lights set up, but the problem i am having is that some photos are being rejected for purple fringing especially when shooting over white what am i doing wrong?

stokfoto · « **Reply #1 on:** July 30, 2008, 05:58 »

hi ,
purple fringing a.k.a chromatic aberration is a problem caused by poor optical quality in other words it is a problem caused by your lens. best solution is to obtain a better lens but there are some ways you can reduce the error during post processing. I am sure there are lots of tuts on that so I'd just google it

good luck

michealo · « **Reply #2 on:** July 30, 2008, 08:04 »

http://istockphoto.com/forum_messages.php?threadid=57368

ichiro17 · « **Reply #3 on:** July 30, 2008, 10:30 »

Quote from: stokfoto on July 30, 2008, 05:58

hi ,
purple fringing a.k.a chromatic aberration is a problem caused by poor optical quality in other words it is a problem caused by your lens. best solution is to obtain a better lens but there are some ways you can reduce the error during post processing. I am sure there are lots of tuts on that so I'd just google it

good luck

Hate purple fringing. Better lenses make a world of difference. But even the best of the best get a bit fringy sometimes. Take my EF 500mm, one of the best lenses, still get a bit of fringing sometimes due to harsh conditions - which is why you need to take the proper steps to limit the situations where fringing might occur.

msv · « **Reply #4 on:** July 30, 2008, 10:36 »

It's one of the worst issues with my Canon EF-S 17-85 IS.
It is very irritating, one of the best things to do is to shoot RAW and fix in software using the manufacturer's plugin/settings for your specific lens.
If you shoot jpg then color replace tool in photoshop is an option.
Anyway I'm looking for a better lens.

Karimala · « **Reply #5 on:** July 30, 2008, 10:43 »

Someone at IS created a fantastic little action for removing purple fringing from your photos...

http://www.dream-fusion.com/mkII/pics/pfkiller.zip

peep · « **Reply #6 on:** July 31, 2008, 01:37 »

Quote from: msv on July 30, 2008, 10:36

It's one of the worst issues with my Canon EF-S 17-85 IS.
It is very irritating, one of the best things to do is to shoot RAW and fix in software using the manufacturer's plugin/settings for your specific lens.
If you shoot jpg then color replace tool in photoshop is an option.
Anyway I'm looking for a better lens.

Where can I find it? I have similar problem with this lens.

litifeta · « **Reply #7 on:** July 31, 2008, 04:53 »

Photoshop fix.

Image>Mode>Lab

Channels Panel
>a>filter>gausian blur 5 pixels >
b>filter>gausian blur 5 pixels >
Lightness>filter>noise>despeckle

Image>mode>RGB.

should look better.

Phil · « **Reply #8 on:** July 31, 2008, 20:32 »

making lenses is a tradeoff between characteristics so different lenses are more prone to it than others. photozone reviews show how much there is for each lens, sometimes a lens has other characteristics that make it worthwhile though (like pentax / tokina 10-17mm fisheye, unbelievably fun but pf is a shocker)

http://www.photozone.de/Reviews/overview

barts pf fix is best I've found (but I haven't tried the istock one yet)

http://littlezumbari.blogspot.com/2006/06/f30-helper-actions-pf-updated-v26.html

phil

chumley · « **Reply #9 on:** August 01, 2008, 10:47 »

basti · « **Reply #10 on:** August 01, 2008, 13:30 »

In case there is simple and efficient way how to remove aberration in PC, no lens manufacturer would bother with producing better lenses. Generally it occurs while using cheap set lens (eg. Canon 18-55 is "great" for that) shooting high contrast things or shooting with sun in the picture. Usually using lens hood and using faster f-stop helps.

Do not compare lenses just with price - eg. some Canon or Nikon lenses costs 2-3x more then same quality Sigma, Tokina or Tamron.

Void · « **Reply #11 on:** August 02, 2008, 15:35 »

i did tests with my own lenses
With some, a large aperture makes the fringe, if I bring the aperture to 16 or 22 it is totally gone.
I would say experiment with the aperture before * with post shooting and very expensive lenses.
PS I have seen the purple fringe on high end lenses too.......

Dreamframer · « **Reply #12 on:** August 03, 2008, 15:07 »

I had problems with purple fringing, but then I noticed that when I use Photoshop to convert raw files I get purple fringing, and when I use Nikon NX Capture for conversion there is no purple fringing at all. I have Nikon camera, and probably their software knows how to correct it automatically... That helped in my case...