First of all thanks for your answers
-I already red the description of the env-light but didn’t clearly understand how these different render modes affect the final look of the Render. AO produces darker results than direct lightening – is this because mantra sends out more samples toward bright areas of the env map? And ray tracing background produces even darker results – but doesn’t it work similar to direct lightening?
@ SYmek : thanks for the tip , but this seems to be too advanced for me since I’m new to Houdini and never really worked with python before - I maybe should keep this question till I’m more experienced in Houdini.