Correct a color cast like a Pro

[JimH]

Also, need to make sure that you have a 3x3 pixel area to sample from. Zoom in to far (and get only one square) and you will sample the surrounding colors which will throw the whole thing off.

[AncientSnapper]

Sorry, but I think you've missed the point - one can post-process this image to get a good result - but the posted method seems to fail, but it is being hailed as a good 1st step.

Incidently you've blown his forehead.

But I 100% agree with you that you should NOT take the shadow point to be the darkest part of the image - it should be the most SIGNIFICANT black point of the image, which is him, not the background.

[AncientSnapper]

I did have a 3x3 sample Jim - are you saying that you can get this image right using the posted method?

[Harry]

Originally Posted by AncientSnapper

I did have a 3x3 sample Jim - are you saying that you can get this image right using the posted method?

Gotta be a little careful using the term "getting it right", and I'm trying to tiptoe a little here.

There is "getting it right", in that the image is correct as shot, real-world right. Then there is "getting it right", as in jacking the settings to make it look better than real life. I hope I expressed the difference correctly.

Reading through the "Skin" book, by Lee Varis, he uses the same procedure using a 5X5 pixel selection and states that if you set your high, low and middle points correctly, the colors have to follow. Now, whether or not it will be pleasing enough is another subject. I have found several instances where setting the mid range produced an unpleasing effect and set only black and white.

Can you submit the original of both of those photos without any corrections for us to play with? I'm not out the whack anybody, I'm just as interested in learning this stuff as the next guy and correcting color cast has always been one of my weak points.

[AncientSnapper]

Sure, the out-of-camera originals are

http://www.broadhurst-family.co.uk/Photos/DSCN4057.jpg
and
http://www.broadhurst-family.co.uk/Photos/DSC_9161.JPG

I can correct them to be what I want - well to be honest the 1st one is very very hard,
but my interest is in new ideas and I just do not think that the method posted will work with a lot of images.

The best I've done with the first one just using curves is this - I know it could be improved with selections & masks.

Have fun!

[JimH]

Originally Posted by AncientSnapper

Sorry, but I think you've missed the point - one can post-process this image to get a good result - but the posted method seems to fail, but it is being hailed as a good 1st step.

Good first step for correcting color cast - yes. If I shoot my calibration target first then I almost always don't use this process. However in the image in question (my Spyder3 calibration is overdue by a couple of weeks - so take that into account) doesn't appear to have a cast. You asked "Could you spare a moment to check that this correction was correctly followed and you get the same results with this image." which is what i did to show you i got a different result - and why (different points used).

Originally Posted by AncientSnapper

Incidently you've blown his forehead.

Hmmm - visually doesn't look like it on this end (will have to open the image back up to check) - but admittedly, i didn't use my other first step which is to sample the threshold for the highest point on the skin and adjust it in an exposure layer where R=240-235.

I think that the only thing these PP tutorials can teach is that there are no absolutes!

[Poco Red]

Jim I get further with your PDf than I do with Emans first post and while this seems like it would be real good to know I'm just feeling dumber and dumber! I can get to the point where I create the layer for Grey point but when I get to Measure Grey layer what levels should be active and which not, as all I seem to end up with is an image that is not much affected by the slider. BTW it took me awhile and a lot of hair pulling to figure I needed to hold down the shift key when clicking to choose the points! Should of re read Harry's post! OK there is a mention of a video by jhilgedick, I do not seem to be able to find the video so any pointers would be apreciated! Thanks for any help or light you can shed!

[JimH]

Originally Posted by Poco Red

I can get to the point where I create the layer for Grey point but when I get to Measure Grey layer what levels should be active and which not, as all I seem to end up with is an image that is not much affected by the slider.

Possible you made a layer copy of the curves layer and not the background layer?

Originally Posted by Poco Red

BTW it took me awhile and a lot of hair pulling to figure I needed to hold down the shift key when clicking to choose the points! Should of re read Harry's post!

I did ... and responded ... and remarked that when I get a chance to rewrite it I would append that section since it was MUCH faster than the way I was doing it.

Originally Posted by Poco Red

OK there is a mention of a video by jhilgedick, I do not seem to be able to find the video so any pointers would be apreciated!

I wish I were that kind of superstar! No video authored by me - I think Harry might have been talking about a video elsewhere that helped clarify some of what I put in the PDF.

Haven't forgotten about this project everyone. Matter of fact, the rewrite will be more step by step with images and screen caps so we can see how each step affects the image.

[Poco Red]

Yay!!!! I finally figured it out, thanks for the heads up on the background vs the curves layer! It doesen't work for all my pics, sometimes this seems to give them a radical color shift ie heavy yellow or one color but on some Wow does it ever make them pop! Here's one from my trip 7 weeks ago from the Grand Canyon!



I am real greatful for all the help I get here on the Camel! While this pic looks OK the full size is amazing!

[AncientSnapper]

Lovely picture Tony - go on - show us the original and then people can see how effective the technique can be!

[Epphoto]

Practice makes prefect guy's
This PP it works !!! but as you know 90% of the time
to prevent color cast, you have to WB your shot all the times, this way you don't have to do this in Photoshop
I'm glad i did help some members here
PS: Tony you have some big time blue on the back in the canyon were it's looks unnatural
and some heavy red in the front also
tone them down a litle and you will be ready to go my friend

[Poco Red]

Eman this was taken at your favorite time of day as the sun was dropping fast! The blue in the back was a mist coming in and the red was from the setting sun. Now how about walking me through how you would make these changes? I've only been doing this for about 4 months digitally and I'm learning so much every day! But to selectively change colors in different areas I need some pointers!

Also, Eman your site is absolutly stunning! Unbelieveable stuff! Did you take the Gorilla's and the Bears at the Pittsburgh Zoo? They along with the Lions are outstanding! What are the dates you are plannng to be in Seattle? I've got a few things coming up in July and I want to schedule some time in to come down and meet you!

Chris I did not keep the original so I can't post it sorry!

[Epphoto]

Originally Posted by Poco Red

Eman this was taken at your favorite time of day as the sun was dropping fast! The blue in the back was a mist coming in and the red was from the setting sun. Now how about walking me through how you would make these changes? I've only been doing this for about 4 months digitally and I'm learning so much every day! But to selectively change colors in different areas I need some pointers!

Also, Eman your site is absolutly stunning! Unbelieveable stuff! Did you take the Gorilla's and the Bears at the Pittsburgh Zoo? They along with the Lions are outstanding! What are the dates you are plannng to be in Seattle? I've got a few things coming up in July and I want to schedule some time in to come down and meet you!

Chris I did not keep the original so I can't post it sorry!

What about sent me the picture with email to see how we can fix it
and this way i can let you know how it was done
I'm going to Seattle on July 19th
I will be visiting the Olympic national park and mt rainier
with my family
I will let you know the dates as soon i find out of my wife the Boss
Email ep.photo@comcast.net
Thanks

[B&W_Fan33]

This is a great topic. But i Have a question i was looking for this type of tutorial but for the gimp 2.4 program. Anyone knows where I can find one?? Thanks

[Epphoto]

Originally Posted by B&W_Fan33

This is a great topic. But i Have a question i was looking for this type of tutorial but for the gimp 2.4 program. Anyone knows where I can find one?? Thanks

Sorry my friend i don't know this program