I want to use Resolve's excellent HSL qualifier to create luma (or alpha mattes) for use in other software.
Can anyone tell me how I would do this? In essence I just want to render the mask I create in Resolve.
A little bit tricky.., one way I think you could pull this off is to add a white image as an "add matte". Make your qualification on your actual image. Then add the white "add matte" into your node tree, apply the qualification key to it (from the node you did your HSL on). Fed that to a node getting an image from the "white matte" then drop the gain to 0 on that node. So that your qualification is now creating a silhouette onto the white image. Feed that image out, and render to file. And you've got an alpha matte clip.
Now, if you can actually follow that instruction, you're a more clever man than I.
You could also try just doing your selection then cranking the gain, gamma and lift ALL THE WAY UP, then do an outside node and cranks all three ALL THE WAY DOWN. So you just end up with a black and white matte image. I'm less confident in this method though.