Using motion blur without changing shutter speed...

[Neilg]

we did an animation about 9 months ago, used physical cameras and exposure, etc. Now that weve upgraded the render farm and need to re-render it, it'd be nice to use motion blur, but its tied to the shutter speed due to the physical cameras. Is there any way to get the motion blur to override the physical camera and just go by frames instead of timings, like how you'd do it if you used a standard camera?

The lighting cant change at all by the way, if it could i'd re-expose it, but its still a bit of a mare and theres no gaurantee it'd be the same. Plus theres the issue of trial and error comparison rendering 20 odd scenes, which I dont really have time to do.

[jacksc02]

it will be much quicker and easier to do the moblur in post. Using the velocity channel you can get some great results without the extra render time

[Neilg]

We do that most of the time, but the render time isnt an issue on this. Because it was made on the old systems it used to render in 10 minutes a frame, but its down to something like 2 after the upgrade.
I just much prefer the look and ive got the time to use it. Plus I want to do it, and our multimedia guys arent busy this week and they'd give me shit for opening aftereffects.

[jonahhawk]

Correct me if I'm wrong. I *think* you can change the shutter speed and offset the film speed to keep the same exposure. i.e. 200ss/400ISO can be the same as 100ss/200ISO. It seems i was experimenting with the same problem you are having...

[Neilg]

I didnt realise they tied in to each other so strictly... Problem solved.