Purple People Eater

[woodrim]

Anyone else here old enough to remember that song?

I do not understand what causes purple fringing, but I do know that I don't like it. I've read that coatings control it. Are there filters that can help?

I like this lens for everything except the purple. Seen here wide open at f/3

[ManualFocus-G]

Outdoors in bright sunshine, I've found UV filters to help longer lenses. However, in the main you're pretty much stuffed and will need to use pp in photoshop or such like. A real pain.

[woodrim]

What method using PS? Need other software or plugin?

[martinsmith99]

I find reducing the saturation of the offending colour usually enough. If it's a small area, I just use the sponge tool to carefully desaturate. Otherwise there's the replace colour tool. There's probably many other ways too, but I never had success using the tool in Adobe Camera Raw.

[no-X]

Purple fringing is caused by axial form of chromatic aberration. There are two main sources:

1. the lens - optical design (APO/superachromatic corrections helps)
2. microlenses on digital sensor (independently on lens used)

There are some mentions all over the net, that purple fringing is caused by sensor blooming. That is not true - sensor blooming affects the entire spectrum, not only its purple part. Sensor blooming can cause the purple fringing to be more visible, but doesn't create it.

[woodrim]

After asking the question, I Googled it and came up with this...
http://www.great-landscape-photography.com/remove-purple-fringing.html Actually works pretty well. Now I'm left with ghosting, but that goes away at f/4, so f/4 is probably where lens needs to be used as wide open.

Here is now processed and sharpened image...

[ManualFocus-G]

Martin is correct, and the method of purple fringe removal you have used is the same, and is the best way IMO.

You can fill the white area left over, if you really want to, by using a small clone stamp. It's still a pain in the backside problem though, and I'm sure a lot of it is caused by the DSLR sensors, but heh ho! Modern AF lenses suffer the same problems and stopping down using sorts it.

[fish4570]

one-eyed, one-horned, flying purple people eater ...

yes, you could say i remember that novelty song. i was in elementary school, maybe seventh grade.

[woodrim]

Well, fish..., you got it!!! And it seems you have a few years on me. I was in maybe 1st grade in 1958 when it came out.

[martinsmith99]

Shooting into light like that would cause a problem on many lenses.

[hinnerker]

[woodrim]

Stopped down to f/8 is a very sharp lens and fringing pretty well controlled. This is the Vivitar 200mm Series 1. Note the dog chewy bone and crumbs on floor

[fish4570]

last one much better.

as for the song, i was off by several years. i would have been in the second grade in 1958, so i only have a year on you.

[woodrim]

Just as an update, I've played some more with the procedure for removing the purple fringing. I used the method outlined in the link I posted earlier. However, I have found that it work better with a combination of the saturation and lightness slider, reducing the saturation first, then lowering the lightness. I'm actually quite amazed at how well it works.

Hey fish, those were the days.

[egidio]

adobe bridge has "defringe" button, and I'm sure lightroom and aperture has this too, but I havent tested

[hexi]

Can you please resize ? my screen is only 17 inches

[woodrim]

Done. Had large size so the fringing could be easily seen.