another use of masks

[eric32035440sekv]

dear all, I do not know whether I am doing something wrong or missing the point.

When using masks, I face quite often the need to select something "difficult" therefore I duplicate and invert another mask and add few corrections if needed (+ or -).

But many times this is not doable because it's not either A or B, there's something else.

So I may try to use intersect function if what I wish to select is shared by both masks.

What if it is just the opposite ?

I would like to have the "negative" of the intersect, in other words make active everything BUT the intersection.

Is this possible ?

thank you

eric

[eric32035440sekv]

and I would also appreciate having as a masking tool for objects, something that would not just be horizontal or vertical (rectangular box), but rather like a lasso

is it available ?

thanks

eric

[Rob_Cullen]

"a masking tool for objects, something .... rather like a lasso"

The Brush can do a good job of 'painting' an area to mask.

[Rob_Cullen]

"..make active everything BUT the intersection. Is this possible ?"   Yes.

An example workflow-

1) Select 'Subject'  (Mask 1)

2) Intersect with 'Color Range'

3) Select the 'Subject' mask (Mask 1) and click the 3-dots icon

4) Invert (Mask 1)

[eric32035440sekv]

thank you for your kind advice

I am attaching a photo taken with iPhone for semplicity

let's imagine I wisjh to selct the rock on the lower left corner (excluding the fingers of the lizard) and I do not want to spend much time with a brush

I will start selecting the lizard (subject) and do few subtractions with a brush over the right leg fingers

I will then add a linear selection starting from the left lower corner up to the limit of the stone

I will then intersect it with the subject selection (unfortunately the system seems not to allow to intersect with a prior mask)

I will then replicate and invert this mask

But either it doesn't work or it seems to select everything else

am I doing something wrong ?

eric

[Rob_Cullen]

Your sample image might require a differnet approach (other than "intersect")-

1) Draw your Linear Gradient across the rock.

2) Click on the [Subtract] button.

3) [Select Subject]