I put the official klein prompting guide into my llm, and told him to recommend me a set of varied prompts that are absolute best to benchmark its capabilities for lighting.

Official prompting guide

https://docs.bfl.ai/guides/prompting_guide_flux2_klein

Lighting: The Most Important Element

Lighting has the single greatest impact on [klein] output quality. Describe it like a photographer would.

Instead of “good lighting,” write “soft, diffused light from a large window camera-left, creating gentle shadows that define the subject’s features.”

Comfy workflow

https://docs.comfy.org/tutorials/flux/flux-2-klein