CM Week 3 -Exercise 6 - Vitus Cathedral Prague

[dkrassen]

Hello.

I adjusted the image in RGB.  The "shingles" area that was exposed to the sun, shadows and neither the sun or shadows all have a hue clock pointing towards green, however, the RGB values vary.  Please explain the relationship between the RGB values and the hue clock.  Please confirm that the longer the hand on the hue clock is the more saturation. 

Please give me your opinion on this correction.

Thank you
David

[ggroess]

The longer the arm the more saturated the color correct.

The relationship of the Hue clock and the RGB values is that the arm on the clock points to the general hue. 
The numbers are the exact RGB values for the pixels under your sample point. 
If you are sampling a large area 11 or so pixels the color will be less accurate in the hue clock information.

For your image you want to remember that the hue of the steeple is consistent regardless of the brightness.  Your goals are to make the three brightness ranges match closely and keep the sky in a reasonable place so that it does not pick up too much red.

Overall you have tried to make the steeple too green and the sky went bad because of it...
Greg

[dkrassen]

Hello.

I decided to take another try at this image too.  I paid closer attention to blue sky so the shingles are not as green.  Do you see some improvement?

Thank you
David

[ggroess]

I do...Much Better
Now...For the final touch....

Add a Glenco Sky pin as shown and adjust the Red channel like a by the numbers correction to fix the steeple.
See screen shot...

Because Skies are so difficult I use a known good sky color pin to help me make it look better...Sky is kind of like skin tones...you don't always know when it's right but certainly know when it's wrong...

Greg