Black frame buffer when GI turned off

[Streetwise]

I'm messing around with AA and have done the following:

All Lights off, Default Lights "On"
Override mtl: standard grey with 8 subdiv
GI turned off

When I render it out, I get black rgb when I would expect to see a clay render. Turning camera exposure off makes it render white. What am I missing?

Thanks.

Edit: To clarify: I'm trying to look at an image with a SampleRate pass with Lights off and GI off and am getting a black output instead of what I would think should be a grey-toned image.

[svetlozar.draganov]

It would be better to attach the scene or a part of it for investigation.