Poser - OFFICIAL F.A.Q (Last Updated: 2022 Jan 27 2:29 pm)
The dome probably is self-lighting in some way. Look at the shader for an ambient value. If you don't see that, post a screenshot of the shader here. We might be able to find something for you.
It sounds like you're describing the Construct that surrounds the set and is always present unless you turn it invisible in the Properties Tab under the Ground prop. If you want it to be completely black and non-reflective, you'll need to enter the Material Room, set the Diffuse and Specular channels to black, and change their associated values to 0. You would need to do this for both the Ground and the Background. I don't know the reason why they are still visible with the lights off but in both cases, the Diffuse channel is set to a light gray.
I've tried twice today to write a response to these suggestions but I don't think that I managed to get it posted. The "Add Comment" button, which I'll try now, has been hidden by Renderosity's notice about cookies. I checked the Materials page for the Flink skydome that I've used. Ambient is set to White and the skydome disappears if I set it to Black. That's not causing a problem for me. In fact, I'm glad that it works that way. I'd just been wondering why a skydome prrop can be seen when the scene's lights are all OFF. Now I know. Thanks to you all for helping!
Ah, you didn't specify that in your OP. You should be thorough in your descriptions and with what products you're experiencing the problems. Otherwise, those trying to help will give you a dozen solutions to other practical problems without realizing that you have something else in mind. Live and learn. We're glad you managed to figure it out.