HPPE4 Chapter 4 Problem

[Cobalt]

I am working through the exercises in Richard Lynch's book and can not get the operation indicated in the text.

On page 77 (Channel Mixing Setup and application) I have worked through the 5 steps and get layers exactly as shown in Figure 4.16. In the last paragraph on the page, it says: "A simple example of how this works is to turn on the view for the Red Subtract 1-100 Layer and increase the opacity. The Red component will gradually fade to black as the Opacity of the Subtract layer increases, and will turn completely black at 100%."

I have gone through the exercise carefully twice but the image never turns completely black. There is always a very visible residual image when the opacity reaches 100%.

Does anyone have any ideas as to what I am doing wrong? I would like to understand the exercise.

Thanks for any suggestions.

[Richard_Lynch]

Can you post a screen shot of the result you are getting?

[Cobalt]

Richard,
Attached are 3 screen shots. One each, with the Red Add 1-100, and Red Subtract 1-100 layers active so you can see the Modes and Opacity settings and then the resultant image.

As you can see there is quite a residual image left.

Thanks for your interest. I am trying to devote a half-hour a day going through the book exercise by exercise.

Carl

[Richard_Lynch]

This setup is not correct. In looking at the thumbnails, the subtract layers have not been inverted. However, in looking at the text, the invert has been omitted. Step 4 should read;

"4. Duplicate the Blue Add 1-100, Green Add 1-100, and Red Add 1-100 component layers, moving each to the top of the layer stack in turn. Rename the layers by substituting Subtract for Add, and remove the word Copy (e.g., change Blue Add 1-100 Copy to Blue Subtract 1-100). Change the mode to Linear Burn, and set the opacity to 0%. Invert each layer (Command+I/Ctrl+I), then shut off the layer view for each Subtract layer."

I will be releasing a set of free tools that will do this correctly. Regretably the tool that comes with the book fails to change the mode of the Red Subtract layer. my tech editor must have been asleep here, as the text should have been matched to the tool. I mean, I should have gotten it right, but with the testing and all I often have many versions of a single tool, and it is easy to insinuate the wrong one.

sorry about the inconvenience. I hope you understand, however, the idea of the mixing, which is that inverted components burn to do the subtraction. You will find that the calculation creates a flat black.

THANKS for bringing that up. I'll need to add it to the errata!

[Cobalt]

Richard,

Thanks for the correction. I will try it. While your noteing Page 77 errata, you might want to change the caption of Figure 4.16 to read .... "after step 5". It's a nit but the figure shows the blank layer with the dashes which is added in step 5.

Carl

[Richard_Lynch]

No problem. Mistakes shouldn't be in the book in the first place, and I realize they are frustrating...but then we wouldn't have the opportunity to have all this stimulating conversation if everything were right the first time ;-)