Motion Blur Bias with Max Physical Camera

[Wilyman]

Hi,

I'd like to use the motion blur bias parameter in a scene with a Max Physical Camera, and I'm unsure how to get it to work.
The parameter in the render settings works with a standard target camera, but doesn't seem to work with the physical cam, and I can't see the option anywhere else.
Does Bias work with the PhysCam, and if so, where do I set it?

Cheers,

John

[kosso_olli]

In a recent project I used the shutter efficiency parameter in the Camera Settings in the V-Ray render dialog. This works together with Physical Cameras, as long as you tick the motion blur checkbox in both locations. I used a shutter efficiency of 0.1, which made the motion blur effect more pleasing. However, this sort of shrinks the blur, so you have to alter the duration in the PhysCam to compensate.
Using the blur bias this way should work as well.

[Wilyman]

Thanks Oliver.
Just tried that, and it does give a nicer motion blur effect than the standard, but I can't get the rear curtain flash effect I was looking for, which I think a high Bias setting would.
But unfortunately with the PhysCam, that setting doesn't seem to do anything.

I'll definitely be using the shutter efficiency settings in the future though, so I appreciate the tip.

Cheers,

John

[kosso_olli]

What do you mean by rear curtain flash? What is the effect you are aiming for?
By the way, I just tried it. You are right, the bias setting doesn't have any effect :/

[Wilyman]

It's basically a long exposure with a flash at the end, so you get the subject in sharp focus at the end of a motion blur.
Like this...



Cheers,

John

[kosso_olli]

Ah, I see. I don't have any ideas, besides rendering twice and then putting the images on too of each other. One with blur, one without. Might that be an option?

[Wilyman]

Ah, I see. I don't have any ideas, besides rendering twice and then putting the images on too of each other. One with blur, one without. Might that be an option?

Yeah, that's what I've done in the past. Just wondering if there's a way of doing it in one, and perhaps having a bit more falloff to the effect.

Cheers,

John