Layer Mask - Curves

[dagabel]

Hello All - I am a new PhotoLine user, and - honestly, new to more advanced photo image processing in general. I have a scanned B&W film image on a part of which I'd like to create a curves adjustment. I've seen a tutorial on how to accomplish this in Photoshop, and am now trying to do it in PhotoLine.

After some trial-and-error, I've done the following:

Created the curves layer
Created a layer mask from that layer (not "Convert for Previous"), which seems to create a "child" of the original - now "parent" - curves layer
Used the eraser tool with the color set to black on the parts of the layer I want to make transparent (i.e., that part on which I do not wish to apply the curves adjustment)

Although the result looks like what I want, I'm still confused about a couple of things:

1. I only want to use the eraser to make parts of the image layer transparent on the child layer mask, correct? Because it appears that I also could do that to the original parent curves layer

2. The Photoshop tutorial emphasized that it's easier to make the curves layer mask adjustments to an image if the color channels are used - it becomes easier to see what you are doing. In PhotoLine, I notice that if I select the child layer mask and then toggle to channels, with my B&W film image I only see one channel: "Gray". Therefore I can't seem to take advantage of this. However, when I select the parent curves layer and toggle to channels, I see an additional channel available: "Special Channel", which when selected in this instance with the B&W image, reveals the eraser actions that I made in the child layer mask in a green color. So although I can more easily see the parts of the image I masked after the fact, I can't more easily see them while making them in the child layer mask. Am I missing something here that would make it easier to perform the layer masking on a B&W image?

3. Finally, I'm not sure I understand the purpose of the "eye and scissors" icon in the layers dialog for the child layer mask. When I toggle it on and off, it doesn't appear to change the image, but only shows the transparency adjustment I made to the child in the layers dialog for the parent itself. Am I missing something here as well?

Thanks very much for your patience with these beginner's questions, and for any help you might be able to provide.
Duane

[bkh]

Hello All - I am a new PhotoLine user

Welcome to the Forum!

1. I only want to use the eraser to make parts of the image layer transparent on the child layer mask, correct? Because it appears that I also could do that to the original parent curves layer

Correct. The child layer is unnecessary in PL (and if you like, you can merge it into the parent layer by using Layer -> Reduce to One Layer), and it's probably best not to use a child layer.

2. The Photoshop tutorial emphasized that it's easier to make the curves layer mask adjustments to an image if the color channels are used - it becomes easier to see what you are doing. In PhotoLine, I notice that if I select the child layer mask and then toggle to channels, with my B&W film image I only see one channel: "Gray". Therefore I can't seem to take advantage of this.

Not sure what this is supposed to mean. Probably the tutorial is referring to a colour image? If it's a free online tutorial, it might be a good idea to quote the URL here.

However, when I select the parent curves layer and toggle to channels, I see an additional channel available: "Special Channel", which when selected in this instance with the B&W image, reveals the eraser actions that I made in the child layer mask in a green color.

The "special channel" is, in fact, the curves "parent layer" which PL also refers to as the "adjustment layer". So you should see the eraser action on the parent layer, not the child layer. I don't know why there is green colour in your case, here (Mac OS X version) it's black and white.

So although I can more easily see the parts of the image I masked after the fact, I can't more easily see them while making them in the child layer mask. Am I missing something here that would make it easier to perform the layer masking on a B&W image?

If you switch on the "eye" symbol of the child layer, it will show up as the "special layer", see below. Apart from that, since you don't really need the child layer, maybe this isn't a problem after all?

3. Finally, I'm not sure I understand the purpose of the "eye and scissors" icon in the layers dialog for the child layer mask. When I toggle it on and off, it doesn't appear to change the image, but only shows the transparency adjustment I made to the child in the layers dialog for the parent itself. Am I missing something here as well?

If you use only the scissors symbol, the child layer will modify the adjustment layer, but if you switch on the "eye" and turn off the scissors, it will be combined with the parent (adjustment) layer according to the chosen blending mode. If the blending mode is "normal", it merely replaces the adjustment layer.

Thanks very much for your patience with these beginner's questions, and for any help you might be able to provide.

No worries, don't hesitate to ask. Btw., these definitely aren't beginners' questions.

Cheers

Burkhard.

[dagabel]

Hi Burkhard - thanks very much for your detailed reply; I appreciate it!

May I ask, what is the purpose of the child layer in PL, in general? I tried working through your suggestions on a duplicated layer, and I think I understand what you're saying about how the eye and scissors work: if I perform the eraser masking on the parent - rather than child - layer as you suggest, turning on the eye in the child basically removes the mask effect in the parent, and applies the curve adjustment to the entire image. Turning off the eye in the child activates the masking effect in the parent.

Does my description of your explanation sound correct?

By the way, the tutorial is actually on a DVD - it's Alain Briot's "Printing Mastery Workshop" for landscape photographers where he describes step-by-step the tasks he uses in Photoshop. Since I've never owned Photoshop, I thought attempting to translate all of those tasks to PL would be a great trial run, and so far, it's working out great! And yes, he's using color digital images in his tutorial.

Thanks again for your help!

Duane

[bkh]

Hi Burkhard - thanks very much for your detailed reply; I appreciate it!

May I ask, what is the purpose of the child layer in PL, in general?

Generally, a child layer can be used to apply an effect solely to the parent layer. For example, you can use an adjustment layer as a child layer which will apply the adjustment only to the parent layer, while a (parent) adjustment layer applies to all layers below. A layer mask only clips part of its parent layer, while a clipping layer as a parent clips all layers underneath. In the case when the parent is an adjustment layer, a layer masks does essentially the same as the parent layer, so I recommend not using a layer mask to keep things simple.

I tried working through your suggestions on a duplicated layer, and I think I understand what you're saying about how the eye and scissors work: if I perform the eraser masking on the parent - rather than child - layer as you suggest, turning on the eye in the child basically removes the mask effect in the parent, and applies the curve adjustment to the entire image.

Yes, it removes the mask effect in the parent but instead the child mask is used.

Turning off the eye in the child activates the masking effect in the parent.

And if the scissors are active in the child, then also the child takes effect.

Cheers

Burkhard.

[dagabel]

Thanks Burkhard!