Is this purple fringing ?

gus · October 30, 2005

I can see a rose colour creeping in behind & to the left & right of the surfer on the crest of the dark wave.

Any way in PS to remove it ?

Andy · October 30, 2005

Yep. AKA chromatic abberation. Best fixed with Shaytech's Color Fringe Remover. Use it in manual mode. Works a treat.

gus · October 30, 2005

I went to buy that a while back from memory but i will not use paypal. It aint the 10 bucks...thats chicken feed for that prog. Shay any other way of dropping $10 in your hand ?

Or is there a way to do it in PS
Gus

marlof · October 30, 2005

Although I got best results with Shay's action, you could also try the free PFree.

Sam · October 30, 2005

Gus,

Was this taken in RAW? If so Photoshop RAW converter has an adjustment for this. Also Neat Image has a tool for fixing this.

If you run out of options, send me the original file, and I'll do my best for you.

Sam

Andy · October 30, 2005

Humungus wrote:

I went to buy that a while back from memory but i will not use paypal. It aint the 10 bucks...thats chicken feed for that prog. Shay any other way of dropping $10 in your hand ?

Or is there a way to do it in PS
Gus

Gus, I'm sure that you could work out a trade with Shay. Send him a bowl of Kava, or whatever

rutt · October 30, 2005

Gus, you're a great straight man. Just so happens I was reading Ch 8 of the LAB book this last week and I learned a trick that is just what you need and really it's just like magic.

Here's the result I ended up with:

Original here.

Here's what I did.

Convert to LAB.
Make duplicate layer.
Select a nice golden ocean color and paint a rather crude stripe over the offending purple spots. You can see that my stripe is very very crude.
Change the blending mode of the layer to Color.
At this point you'll probalby be very happy and can quit. But I wanted to finish trying out Dan's technique and make sure to limit the blend to only the offending purple color. So I brought up the Blending Options dialog box (right mouse on the layer in the layer pallette.) and used a blend if to limit the blend to only areas containing some magenta:

Notice the split slider. This makes the transition from no blend to blend gradual though the range of the split. Without the blend if I was able to see a small difference where there was no purple. It's subtle, but we don't want it. With the blend-if, I think the result looks perfect.

DavidTO · October 30, 2005

Looks to be a good solution for what's basically a duotone image. What about something with more complicated colors?

gus · October 30, 2005

Thanks rutt...always on the job..i will get into it now.

David that aint no duo-tone...thats 6am looking straight at south america.

DavidTO · October 30, 2005

Humungus wrote:

David that aint no duo-tone...thats 6am looking straight at south america.

I know it's not, but as far as understanding Rutt's procedure, it may as well be. My question is what to do when the color palette is more complicated...

cabbey · October 31, 2005

funny this topic should come up
I was just about to ask this very same question on an image of mine that has a bit more colors (2 really, instead of 1).

(links to galery with full size original) Note the slight purple fringe seperating the petals from the greenery in the background. I hadn't even noticed it in the original image, but when I got it printed at 8x12 on lustre paper, whamo! it was quite noticable.

cabbey · October 31, 2005

andy wrote:

Yep. AKA chromatic abberation.

So, just to confirm what my research is saying... this is not something I'm doing wrong in shooting, it is inherent in the quality of the kitty glass that cannon packed with the 20D, right? (Don't even get me started on the that issue... showing L glass on the box and then packing non-L in the box... that's just evil is what that is. Hey Cannon art department:

)

rutt · October 31, 2005

DavidTO wrote:

Looks to be a good solution for what's basically a duotone image. What about something with more complicated colors?

I just finished the chapter yesterday and I'm still chewing on it. I'll post a summary pretty soon and we can try to figure out it's limits.

The paint brush was a pretty crude way to get the color I wanted and that wouldn't work so well if I wanted something more complicated at the edge. On the other hand, using a color layer and blend-if's is really the heart of the technique and that just depends on being able to define the color you don't want very precisely.

Here is a very very very close crop of Cabby's rose:

I made a layer and subjected it so some very unsymetrical LAB curves in order to create a transition without a hint of that obnoxious purple:

The color of this isn't a good match for either the rose or the background, but no matter. I only care about the color of the transition. My LAB curves were quick and dirty. You can be as careful as you like about this when you try it at home.

I used blend-if's for both A and B channels to limit both sides of the blend to just the transition:

I got this result:

cabbey · November 3, 2005

rutt wrote:

I just finished the chapter yesterday and I'm still chewing on it. I'll post a summary pretty soon and we can try to figure out it's limits.

So it looks from the sample you showed to be workable... wonder if I could get the gimp to do it.....

buzzard_nuts · November 3, 2005

Change the blending mode of the layer to Color.
At this point you'll probalby be very happy and can quit. But I wanted to finish trying out Dan's technique and make sure to limit the blend to only the offending purple color. So I brought up the Blending Options dialog box (right mouse on the layer in the layer pallette.) and used a blend if to limit the blend to only areas containing some magenta:

Notice the split slider. This makes the transition from no blend to blend gradual though the range of the split. Without the blend if I was able to see a small difference where there was no purple. It's subtle, but we don't want it. With the blend-if, I think the result looks perfect.

[/QUOTE]

How do you decide on the range?

138-152
Can you set up the info pallette to give you these numbers or are they done by just looking at the picture.
Sorry if I'm asking a stupid question
buzz

rutt · November 3, 2005

buzzard_nuts wrote:

How do you decide on the range? 138-152
Can you set up the info pallette to give you these numbers or are they done by just looking at the picture.
Sorry if I'm asking a stupid question
buzz

THis is a great question. The answer is I did it by eye. First I moved the unsplit slider to determine the range of interest. As I moved to the right it excluded the areas with green. At some point it also started to exclude the areas I wanted to blend. At this point I backed off a small amount, split the slider and moved the left side (where the blend starts) back just until the transitions softened. This process is like using USM; it takes a little practice, but you'll get the hang of it.

Is this purple fringing ?

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