Do you consider instead of throwing money to rebus to hire someone who will optimize your scene for 100-200pass max? I never render 200+ but i know this was also too much with wrong setup.
I am interested to know if 400 passes is typically enough for every situation for most users, so thanks that's good insight.
For my own part I'm generally much happier to keep a scene complicated and make up the extra cost associated with that choice myself.
I'm a freelancer who works in isolation so my main source for comparison is info from this forum - I will have a look at suggestions for optimisation.
An issue I was having previously with this scene was that individual test frames would look okay in terms of noise at a lower level of passes but animations revealed swimming noise in GI in some areas, glossy reflections in others.
Therefore, the testing itself gets more time consuming, expensive and speculative (having to test sequences of animations in motion rather than being able to rely on individual frames).
So, yes, 600 may seem high but I am at least confident that I had something that worked and I'm not going to be spending money on final renders that I can't use.
Anyhow, this choice on the users part is a separate issue from the fact that some period of notice to the changes in Rebusfarm's capacity would have been professionally sound.
They do invite customers to buy credit for the service based on the principle of a few test renders working to the customer's satisfaction.
If renders can run at 600 passes one day and then cannot do so the next day without prior notice this is not great practice.
I've yet to hear back from them whether it's possible to temporarily bypass the limit though. Maybe they'll offer a solution.