Wratten 25A exploits

[colinbm]

I spent the day trying to replicate a photo I saw on Photoni's flickr page....

 

Nearly got there ?

 

Here I show the raw converted to .jpg, then a channel swap, RGB to BRG.

I can't work out what I have to get the raw to look like to end up with this yellow that photoni got, instead of the greenish yellow that I have ended up with ?

 

Raw to .jpg.....

 

 

 

Swap RGB to BRG

 

[Stefano]

You need cyan foliage to turn it yellow. In your raw image it is too blue.

 

Cyan = G + B

Yellow = R + G

 

You put the green channel into the red channel, and the blue channel into the green channel, so you go from G + B (cyan) to R + G (yellow).

 

I don't know how to shift colors that way.

[colinbm]

Thanks Stefano

I don't know what Photoni's raw looked like ?

I can't get my head around what my raw must look like to get the yellow after the swap ?

[Stefano]

Cyan foliage with red sky (for a blue sky) or magenta sky (for a cyan sky).

[Stefano]

Red -> blue

Yellow -> magenta

Green -> red

Cyan -> yellow

Blue -> green

Magenta -> cyan

 

RGB on the left, BRG on the right. You can read those arrows both ways (RGB to BRG or BRG to RGB).

[colinbm]

I am close to that......red / magenta sky, haven't I ?

So does it needs to be closer to red or magenta ?

[Stefano]

A redder sky will become bluer. A more magenta sky will tend towards green (if you want a natural-looking sky you want it mostly blue with some green (and a little red).

 

For a more natural-looking sky you need to shift it towards magenta.

[colinbm]

I want the yellow vegetation like photoni has ?

[Stefano]

In Photoni's photo the sky is blue, if you like that then keep it as red as possible in the raw image.

 

For a yellow vegetation, you need to have more green (or less blue) in your raw vegetation.

 

There are some softwares which allow you to rotate colors a bit, Andrea does it, but I don't know how to do it.

[colinbm]

I can shift the colours a bit in the Sigma SPP processing program with the colour picker, but I haven't got the results I want yet.

Rotate colours I don't know ?

I used Irfanview to do the swaps.

[colinbm]

I took the .jpg of the raw file & moved the colour picker around to get a reder sky & greener vegetation.

Opened that in Irfanview & swapped the channels to BRG, then in colour corrections I made small adjustments to get this.

Interesting the younger growth of the mangrove is magenta & the older is yellowish. On the hills in the background the eucalyptus trees are magenta.

Not what I was after but shows variation in the vegetations.

 

[Andrea B.]

Don't forget that you can take a yellow-green color and easily shift it to yellow with one of the color tools in a converter. Given that it is all false color, I don't think there is any Purity Penalty for not quite getting the yellow you want straight-out-of-camera. Of course, I do understand the challenge in wanting a straight-out-of-camera yellow.

 

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We here at UVP must be the only people in the world who think all these oddly colored photos look correct. :lol:

 

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Oh, woops. I missed the comment that Col did try a color shift. Apologies for repeating the usual!

 

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I can't get my head around what my raw must look like to get the yellow after the swap ?

 

Yeah, I'm being puzzled too. Let me try a few things with Raw Digger.

[Stefano]

I can't get my head around what my raw must look like to get the yellow after the swap ?

 

Yeah, I'm being puzzled too. Let me try a few things with Raw Digger.

As I said, it should look cyan (0, 255, 255 or darker of course).

 

You can try with other filters and other swaps different than BRG.

[Stefano]

How to obtain yellow with all 6 possible swaps:

 

RGB = yellow (trivial)

RBG = magenta

GRB = yellow

GBR = cyan

BRG = magenta

BGR = cyan

 

So if you have filter combinations that yield yellow, magenta or cyan vegetation, you can try those swaps to get yellow (the GRB swap is not as trivial as the RGB, because the yellow will stay but the sky will change color). Hope there are no mistakes.

[photoni]

after reversing the Blue> Red & Red> Blue channels

first I increased the brightness and contrast

I have twice applied channel mixer

lastly, selective color correction

(I play / work with Photoshop 3 [bw version] since 1997)

 

is a photoshop CS action in Italian, with some changes I think it can be used in the English versions, if you need my e-mail is photoni@tiscali.it or www.collodio.com

[colinbm]

Thanks Toni, You have shown it is possible with PS, but I don't have PS & my brain is hurting

[colinbm]

Thanks Andrea, I really shouldn't set the bar so high on myself.

Maybe I should stick with 'KISS', keep it simple stupid, & stick to getting SOOC with different filters, in real life & not virtual reality.