Flower vendor using the Jacob's Ladder

Jacob Rus's new curve-based technique, with examples
ggroess
Posts: 5342
Joined: Wed May 24, 2006 2:15 am
Contact:

Postby ggroess » Thu May 21, 2009 8:07 pm

Jacob...

Attached is a image from the class that I have tried to use the JL process on.
Some comments and questions....if you don't mind...

I find myself feeling like I hit this with a very large hammer and then pounded it into shape slowly.  What I guess I mean is I had to make grand changes to see some of the effect and then tweak it back problem by problem to get it somewhere near what I thought it should look like.  Is that because of the "zoom" layer or am I missing some other part of the process that makes the changes easier to see.

I did open a hue clock on the image but I found it really difficult to hit the skin tones.  Without the PS info pallet it was very dicey to get anywhere near what I thought a correct value was.  Is there any way you can see to allow the info pallet to sample the original without the overlaying filters?  I could not divine one; but I certainly am not the PS expert I have my pattern of use and I keep pushing myself into new areas.

Here are my curves and the images...
Any additional information anyone could add would help me get a better understanding of this interesting technique.
The last image is a screen cap of the original image found in the CM class work I can post a better version if needed.
Greg



mikemeister_admin
Posts: 4925
Joined: Fri Sep 20, 2013 8:29 pm

Postby mikemeister_admin » Thu May 21, 2009 9:35 pm

Greg, you do not say what 'controlling' channel you used.

Here is a very quick attempt (less than 2 mins) using the L channel (with my action "Manual by Lch") with no curving of the L channel before using the Jacob's layers - not much change to the contrast, but I could have dialed in more.  I left the zoom opacity at 80%.

What I don't see how to do is add saturation, but I'm happy to do that as a separate step.

Does this simple curving help at all?

Chris




ggroess
Posts: 5342
Joined: Wed May 24, 2006 2:15 am
Contact:

Postby ggroess » Thu May 21, 2009 10:46 pm

Zog are you using CM as a smart filter in place of one of the Layers??

Interesting...I though about that but was unsure how to implement it.  If by controlling layer you mean which layer did I do my adjustments in I used the LAB version of the ladder action.  I then adjusted L in the L channel adjustment layer colored red and the other channels in each of the other red highlighted layers.  I made sure I changed the channels when I went into each one so i was not just adjusting the L channel always.

Your question leads me to believe that I am missing the boat totally here...

Greg

mikemeister_admin
Posts: 4925
Joined: Fri Sep 20, 2013 8:29 pm

Postby mikemeister_admin » Thu May 21, 2009 10:58 pm

I think you are missing something - I certainly got confused when I started.

I do not think it is possible to use CM, I just used its curves for a quick screen grab.  I did everything in PS. 

If you have downloaded my actions (http://www.broadhurst-family.co.uk/lefteye/MainPages/jacob's_actions.htm), then just run the "Manual by Lch" on the rgb image - answer yes to both dialogs and then play with the single "Curves 1" layer - that should get you going.

Does that help? - if so then you can 'progress' on to Jacobs action (2nd image) and his more complete layers.  But I'm simple minded and rarely use all three.

I'm off to bed now - have fun and if I can help leave a message and I'll answer tomorrow
Chris

ggroess
Posts: 5342
Joined: Wed May 24, 2006 2:15 am
Contact:

Postby ggroess » Fri May 22, 2009 1:11 pm

Ok I tried it your way...
Much easier at least for now...


But there is trouble in paradise...In shot 1 I have a reasonable correction unitl......

In shot2.. I zoom into the face to see whats going on...

I tried to kill this off but was unsuccessful.  any thoughts??

Greg


mikemeister_admin
Posts: 4925
Joined: Fri Sep 20, 2013 8:29 pm

Postby mikemeister_admin » Fri May 22, 2009 3:05 pm

Hi Greg,

You still do not say what controlling channel you are using - the selection of that is effectively the mask and if you go for the Auto ones, then it equalizes the channel before starting - this most likely introduces banding, so one then needs to blur.

I just used the L channel without any pre-curving.

One of the problems in using Masks in CM is curving it correctly - the same is true of JL (I think).

Remember I'm only a beginner in colour correction.  I certainly do not understand the maths behind this technique and to do it properly it really needs Jacob's input (when he has finished his exams).  One of the things I can not work out is why when curving in say the A channel, the B values also change (it could be my crude Colour Watcher reading screen colours, not the actual ones) - however when I play with the L channel, the colours do not change. 'Tis a bit of a mystery that may well be tied to the Linear Light blend and the maths. No doubt when more people start to play with this technique, all will be revealed.

If you go slightly mad and over the top, when making colour changes, then playing with the Zoom opacity may help you understand what is going on and how one can play with the correction curve.

I should try some other images - take the CM course car/fire engine colour change ones and see if that help to reveal more of the way this technique works.  You can also change the blend mode to any of the Overlay ones (not pin light) and have the same sort of control, but in differing degrees.

The main downside to me, is that the info palette will not work and that CM can not be used to curve (I no long enjoy curving in plain PS).  Also one begins to feel lost without the superb hue clocks.

ggroess
Posts: 5342
Joined: Wed May 24, 2006 2:15 am
Contact:

Postby ggroess » Fri May 22, 2009 4:57 pm

Within the context of masking this makes more sense.  It seems like this is very similar to the "CM version of Man from Mars" where you take the K channel and make it a saturation slider.  The curve is flat, Horizontal, and when you adjust the vertical position you reduce or enhance the effect. 

I think what might be going on as far as my image is that the mask is made in the A channel and then the color has more of a role in the correction.  It would also explain the banding since the channel data for A and B is coarse.  .

See shot1 below.  It is the CM A channel mask adjusted so you can see the face.
BTW The Manual L channel part of your action does not leave the image with a curve layer unless I am applying it wrong.

Greg

mikemeister_admin
Posts: 4925
Joined: Fri Sep 20, 2013 8:29 pm

Postby mikemeister_admin » Fri May 22, 2009 5:12 pm

Ah - re the Manual Lch action - it uses one of my standard subroutine actions and I expect that is upsetting it.

The action is as follows (if it is of any help)
Action: Manual By Lch
Duplicate first document
Convert Mode
To: Lab color mode
With Flatten
Play action “ColourByLch” of set “CBsActions-JacobsLadder”
Select layer “Curves 1”

Action: ColourByLch
Play action “CurrentImage” of set “CBsActions”
Set current layer
To: layer
Name:  “Toned channels”
Select lightness channel
Curves
Gaussian Blur
Radius: 0.1 pixels
Set Selection
To: all
Copy
Select a channel
Paste
Anti-alias: none
Select b channel
Paste
Anti-alias: none
Show lightness channel, a channel
Select Lab channel
Set Selection
To: none
Set current layer
To: layer
Mode: linear light
Play action “Flat Curve” of set “CBsActions-JacobsLadder”
Play action “Zoom” of set “CBsActions-JacobsLadder”

Action: CurrentImage
Make layer
Without Below
Set current layer
To: layer
Name:  “CurrentImage”
Merge Visible
With Duplicate

Action: Flat Curve
Make adjustment layer
Using: adjustment layer
Type: curves
Adjustment: curves adjustment list
curves adjustment
Channel: lightness channel
Curve: point list
point: 0, 127
point: 255, 127
curves adjustment
Channel: a channel
Curve: point list
point: 0, 128
point: 255, 128
curves adjustment
Channel: b channel
Curve: point list
point: 0, 128
point: 255, 128
Group

Action: Zoom
Make adjustment layer
Using: adjustment layer
Type: curves
Adjustment: curves adjustment list
curves adjustment
Channel: lightness channel
Curve: point list
point: 0, 63
point: 128, 128
point: 255, 192
curves adjustment
Channel: a channel
Curve: point list
point: 0, 103
point: 128, 128
point: 255, 153
curves adjustment
Channel: b channel
Curve: point list
point: 0, 103
point: 128, 128
point: 255, 153
Group
Set current layer
To: layer
Name:  “(zoom)”
Set current layer
To: layer
Opacity: 80%

My! never realized there were so many steps - I just think of it as applying the L channel to the other two and changing the blend !

ggroess
Posts: 5342
Joined: Wed May 24, 2006 2:15 am
Contact:

Postby ggroess » Fri May 22, 2009 5:23 pm

Hmmm.. I have those actions as well..More playing needed here...


Greg

mikemeister_admin
Posts: 4925
Joined: Fri Sep 20, 2013 8:29 pm

Postby mikemeister_admin » Fri May 22, 2009 5:27 pm

Strange - you should be just able to hit the action from an rgb image and everything should work out after you accept the curve & blur dialogs


Return to “Jacob's Ladder”

Who is online

Users browsing this forum: No registered users and 2 guests