Gradient Map Adjustment Layer "Opacity" doesn't work

[TomAlphabet]

Gradient Map Adjustment Layer Editor has 2 kinds of sliders - Color and Opacity. The Color sliders work fine - place one at the luminance value desired and select a color to be mapped to that value. AFAIK Opacity SHOULD work in a similar way - place one at the luminance value desired and select an opacity level, which should determine the "intensity" of the gradient remapping at that particular value. So my understanding is if you want blacks to be fully affected by the specified gradient map and whites to be completely unaffected, you would add a 100% opacity slider at the bottom end, and a 0% slider at the top end, then the gradient remapping opacity values would interpolate in betweeen. BUT assigning 0% to an opacity slider has NO effect, so there is no way to achieve this result. FRUSTRATING.

See screen below - the preview SUGGESTS the gradient remapping at the top end of the scale would be fully transparent, showing the checkerboard beneath, but that is just not how it responds on the actual image. The gradient at those luminance values comes through at 100% as though the opacity slider doesn't even exist.

[PECourtejoie]

Hi, Yes, and no, the Gradient Map uses the Gradient Editor to tweak the maps, so technically, it is not the Gradient Map Editor

The opacity setting should be disabled for the gradient maps, as they are designed to change the colors, not to alter the opacity. 

I understand what made you believe that

If you'd like to change the transparency based on luminosity values, you should rather look into the Advanced Blending Options: 

https://helpx.adobe.com/photoshop/using/layer-opacity-blending.html#specify_a_tonal_range_for_blendi...

Or search for "blend if" on this page: https://jkost.com/blog/2020/10/working-with-layer-effects-and-layer-styles-in-photoshop.html

Remember that a group can have blend ifs, and you can adjust the opacity that way, especially when splitting the cursors.

[TomAlphabet]

Hi - thanks for the response. For reference, there is a simultaneous discussion in the community forum here, and elsewhere - seems like this is a fairly common complaint:

https://community.adobe.com/t5/photoshop-ecosystem-discussions/gradient-map-foreground-to-transparen...

I think people are aware there are more labor-intensive workarounds, including using layer blending options as you describe, but the frustration is that the tools are RIGHT THERE in the Gradient Map Editor, but that they are disabled. There is the potential for this tool to be so much more useful and powerful if those opacity sliders were just enabled! 

If - as you say - there was never the intention for the Gradient Map tool to work in this way (WHY NOT?!) then why are all the embedded opacity features there in the first place, and have been there for so long?! For a company of Adobe's scale and resources, I don't buy the reasoning offered in the community thread that the dev's simply didn't have enough time or resources, so had to quickly copy/paste code from the standard Gradient Tool, including opacity features that do nothing in this case.

Either enable the features that have been staring users in the face for years (PLEASE!?), or develop a custom interface that reflects the functionality the tool actually offers!