My question is when adding the Specular layer (through linear dodge(add)), it essentially makes my image overall darker and if I try the blurring trick for a gloom effect it just adds a black blur…
How can I output a decent Specular pass?
The way my scene is set up there are panels reflecting light into the bottle/tube thing, and the background is set to black. My concern is that when I render separate layers and add my Spec in it comes out darker than my ‘beauty’ render.
Also this inhibits my ability to blur this map and create a nice gloom effect, as the tutorial shows.
Well, specular is only part of the problem did you also add the reflection? Usually you will need to split out all the elements and rebuild them all back together. Simply taking one element will not match the beauty render.
I guess it would be best to send your files to our support guys at vray@chaosgroup.com - they will be able to look into this in more details and provide you with more specific instructions how to make it work.