Photoshop LAB question about Blend-If settings

jfriend

As I'm now a convert to frequently using Layer/Blend-If settings to control layer blending in LAB mode, I'm trying to figure out why the blend-if sliders are numbered 0 to 255 instead of -128/128 for the A/B channels and 0 to 255 instead of 0 to 100 for the L channel? Is this just an oversight by Adobe? Is there a pref to change this? Or is there some reason it is the way it is?

I ask because I will commonly be examining my image and find that I have a clear separation between two objects around a particular L, A or B number. I then go to the Blend-If sliders and I can't use those numbers because the sliders use a completely different numbering scheme. I have to do it by eye. Weird.

Here's a screen shot of the A channel sliders that shows the 0 to 255 numbering:

DavidTO

Good question, John. I never noticed, but I always went by look. Interesting idea to go by the numbers...except for the fact that Adobe screwed it up!

Looking forward to hearing an answer on this from someone more learned than me.

rutt

I think David is right. Adobe needs to read Dan Margulis over and over again until they get every little detail like this right.

To quote our feerless leader: "Doesn't it just suck when you don't get what you want?"

jfriend

I'll post in the Adobe Photoshop forum

rutt wrote:

I think David is right. Adobe needs to read Dan Margulis over and over again until they get every little detail like this right.

Since it doesn't appear I just overlooked something simple, I decided to ask the same question in Adobe's Photoshop forum. I'll report back if anything useful turns up there.

jfriend

Adobe responds

jfriend wrote:

As I'm now a convert to frequently using Layer/Blend-If settings to control layer blending in LAB mode, I'm trying to figure out why the blend-if sliders are numbered 0 to 255 instead of -128/128 for the A/B channels and 0 to 255 instead of 0 to 100 for the L channel? Is this just an oversight by Adobe? Is there a pref to change this? Or is there some reason it is the way it is?

Chris Cox of Adobe responded in this thread in the Adobe forum and said: "The sliders don't know or care anything about the color mode. Yes, it's just an oversight (but a really, really minor one)."