Render taking longer

[joon_lee]

Hello,

So, I would start rendering a scene with say 100 frames. The first frame takes 20 second long so I'm thinking this would go fast and it's not that complicated scene.
However, the render would start taking longer and longer after frame 70 or so and would start taking minutes per frame.
If I restart the render from that frame, the render time would be normal again.
What am I doing wrong??

[hermit.crab]

Hard to say without the scene itself. Best you use the contact form to attach the scene and explain your issue.