I thought (and could well be misremembering) that light sources were or could be made to not show up in a render. Maybe this is how it's supposed to be? Maybe I misremember? But what I'd like is for the light source, here reflected in a mirror, to be invisible.

Ah. It's the mirror. Hmm. Anyone know how to make a mirrored surface not do that?

This is the definition of the mirror surface:

IIRC, there isn't a solution for reflected lights in mirrors.  You may need to angle the light so that it doesn't appear.

Thanks. I was kind of figuring that angles would be the best I could do. Sigh.

Your other option is to shrink the light to a speck and then postwork out that speck. The problem is depending on the type of light, that makes the shadows very sharp.

Thanks! I did try that. Oh well.  And mostly I like that Poser lets me do things in the same manner and with the same abilities and restrictions as I would experience in a really well equipped photography studio, including lighting and camera controls, and all with models who never get tired and don't charge by the hour. I used to own a small photography studio, so I find that bit rather cool. But I had definitely gotten spoiled with the magic of invisible cameras, photographers, and lights. At any rate, this is definitely a limitation that I'd have found in a RL studio. Sigh. Never slowed me down in a RL studio, so I should just shut up and quit complaining.

My biggest problem is that it's been over twenty years since I last used Poser, and that makes for a steep relearning curve, not to mention that things are just flat out different than they were back with Poser 4.

I've seen comments on another forum I visit regularly that raising the Roughness value to either .1 or .01 will do what you want.  The comments were in a Blender thread (they deal with gaming so no Poser on that site) and It seems that Roughness is the way to get rid of it being visible in a render.

I don't recall if I've played with it much, and don't know off-hand if there's another setting (or two) that may help in that regard, but nodes are nodes and probably work pretty much the same in both software packs.

I shall try that! If it works, then there's definitely chocolate.

Sigh. Doesn't seem to help, but thanks for the suggestion! Sorry though -- no chocolate.

What is the smallest scale you are using for your light source?  I would try reducing the scale to either 1 or 0.5 percent. I'm running some test renders and that small value seems to hide the light in the reflection.

That seems to work!! In fact, it appears that making the scale negative works too. Strange. I tried it using a spot, and I think the shadows look fine. I'll try later with an area light, which comes close to simulating a studio softbox, in which size *should* affect the softness of the light. We'll see. First breakfast and other morning chores.

Meanwhile, chocolate...

Couldn't wait, Fed dogs, came back and tried area light. Not so good on the shadows.

With scale set to to 50%:

With scale set to .01%:

But it will definitely work in some situations. So:

And thank you for the tip!

Adjust distance and intensity as needed. 

Gotcha. Thanks again.