Transparency mask when rendering through a mirror reflection?

Falco

I have an object in front of a transparent background / nothing.  When I render it normally in iray, it looks fine and correctly has nothing in the background and I can select the alpha in photoshop.  However if I try to render a mirror reflecting that same object and background, it will render the environment dome (that is set to draw dome off), or if I set the environment map to 0, it will render black for the background without the alpha cutout. 

The core issue is that I'm trying to create an alpha of the character which has soft hair in photoshop, so I need a pixel perfect transparency mask to properly mask it out.  Is there any way to do this when reflected through a mirror?

crosswind

Yes, Dome is always reflected on specular surface even if you turn off Draw Dome. You may use an HDRI map with pure white light source...