Env camera images are bright and grainy

What is wrong

• The ready-made envs' camera observations (camera=True: 64 x 64 pixels, 4 samples per pixel, no denoiser, the default studio light) come out bright and with visible sampling noise.

Number

• On a table, cube and ball scene seen like the env camera: mean brightness 214 of 255, and 3.9 grey levels RMS noise against a 256-sample image (95 % of pixels within 5 levels).
• More samples cut the noise: 1.5 levels at 16 samples, 0.7 at 64. Each step costs about that factor in render time.

Why

• The env camera favours images per second for training (4 samples, no denoiser) and uses the studio light of the quick-look renders.

Workaround

• Build your own alloy.camera.Camera(..., spp=16) over the env's sim for cleaner images, and pass render(..., exposure=-1) (one stop darker) when the images look washed out.

Planned fix

• Expose the env camera's samples, denoiser and exposure as env options (after the launch).