adding multiple transparency layers

[thistleknot]

I used to have this answer saved somewhere, but I can't find it.

 

If I'm doing multiple layers.  I recall a way to ensure their transparency affects added to an original opacity level.

 

For example.  The underlying (bottom most image) transparency is set to 255

and the next one is set to a fraction of the prior level (it's not 50%... I think it's something like the last value / 1.6), so the next would be 160?

 

Something like that.

 

Basically.  If I have two images, and one I apply a mild affect to (say a blur) and I want to layer this over the original image (which is set 255).  There is a specific fraction of the prior opacity I set the new one to to ensure I can keep adding these affects together smoothly ad infitum (limited only by integer division).

 

 

[Reptillian]

So, just to be clear, you want to increment using last layer, or swapping layers to use as increment, or use flattened copy?

[Rick Brewster]

Edit the layer's properties and set the blend mode to Additive? Is that what you're looking for?

[Pixey]

Hello @thistleknot and welcome to the forum

 

Perhaps this is the 'tip' you are referring to:   "But all have different transparency settings, add a new layer underneath all of them and merge them with the new layer, starting from the bottom layer."

[HyReZ]

3 hours ago, thistleknot said:

If I have two images, and one I apply a mild affect to (say a blur) and I want to layer this over the original image (which is set 255).  There is a specific fraction of the prior opacity I set the new one to to ensure I can keep adding these affects together smoothly ad infitum (limited only by integer division).

It appears that you are seeking an emperical solution to an outcome that is mainly aesthetic.
If the bottom layer is set to 255 (zero opacity), then you should adjust your other layers opacity/transparency properties until it 'looks right'!
I deal with this countless times. I try to set things up using percentages of transparency only to find when I rearange layers things dont 'look right' and I have to make readjustments until they do. Your eyes are the best indicator for correctness in these situations.

[MJW]

Do you mean you want to set the opacity of each layer so they all are given equal weight when blended? If so, each layer's opacity should divided by its distance from the bottom, starting at 1. (Luckily, I found a recent thread where this was discussed.)

 

So for five layers:

Top:   Opacity 51 = 255/5

Next: Opacity 64 = 255/4 (rounded)

Next: Opacity 85 = 255/3

Next: Opacity 128 = 255/2 (rounded)

Base: Opacity 255 = 255/1

 

(I'm not sure this is what you're after, since you specifically said the second layer opacity isn't 50%, which is what it is for the method I give.)

[thistleknot]

I'm not sure how to describe it.  I'll try MJW's method.