Curvemeister Forum

Mike has asked me to shoot the image from a canyon that cannot be improved in LAB. 
I know you all love a good challenge. 
My best result is in RGB so far....
This image was shot at sunset it is a lengthy exposure....

Give it a shot...

Greg

I think you need a course in exposures!! - only joking Greg.

This is not the day to post a challenge and say Lab is impossible.

Just a quick fiddle only in Lab - I'll try later in the week when I have time as this is persumably not the effect you are looking for!

Chris

Greg,

My shot at it in Lab only.

Ian

The rock in the foreground is too blue.....Try it in RGB and set a reasonable neutral and you will see what I mean...

Mike's challenge to me was..."go on vacation and try to shoot an image of a canyon that cannot be improved in LAB."

90+ percent of the images I shot last week can indeed be improved in LAB...I found this one to be a real problem child...I will post my RGB later this week....

Greg

Greg,

I see what you mean ..... second try.....

The rock in the foreground is too blue.....Try it in RGB and set a reasonable neutral and you will see what I mean...

Mike's challenge to me was..."go on vacation and try to shoot an image of a canyon that cannot be improved in LAB."

90+ percent of the images I shot last week can indeed be improved in LAB...I found this one to be a real problem child...I will post my RGB later this week....

Greg

What are the characteristics of an image that make it unsuitable for correction in Lab mode?

Well for me it has been the fact that no matter what I do to it I cannot make it look like it should.  I cannot get rid of the yellow green cast when I set a single neutral. 

It can be improved but When I use RGB I get much... much better results.

Greg

Well for me it has been the fact that no matter what I do to it I cannot make it look like it should.  I cannot get rid of the yellow green cast when I set a single neutral. 

Here's my fix. I also couldn't get anything decent looking from lab mode. Looking closely at the image with the aid of the hue clock, you can see there's a blue cast which gets deeper as the tones get darker. I think that's the key; the CM help text says that RGB is good at fixing problems where a colour cast is associated with a change in brightness, and that's exactly what we have here. I can't claim to understand the theory why that's true, but the curve shown below does get a decent result.

After the colour fix with RGB mode, I added another conventional pass in Lab mode to lift the brightness and increase the saturation. It's actually possible to lift the brightness to the point where it looks like a daylight shot, but since it was a long exposure sunset shot I tried to keep it a bit dark and saturated, like perhaps the view appeared at the time.

Derek,
That is where I got it in RGB as well...I like this one so far....

Greg

I think that is absolutely excellent Derek,

I'm puzzled by one thing - I tried to copy your curves to see what was going on, and I noticed that I could not get the histograms to be anything like yours (see below), especially the red and green channels - so I guess you did at least 3 passes.  The first to lighten, then RGB, then Lab - is that right?

I had this problem on the course where I could not get my histograms to look like other people's - Mike suggested the difference between precise mode being on/off.

Does anybody else have this problem with histogram representation?

Thanks
Chris