Motion blur is handled by the post processing option under the video menu. There is no islated motion blur option. It is handled by an encompassing "post processing" selection.

Maybe there should be an option to turn off motion blur separately from other post processing effects?

Definatly agree with this, motion blur should be a separate option !

Not just for motion blur, separate settings for every option the post processing adds!

Glad to see that people agree.

A separate options for each post processing effect would definitely be great. Would allow players to pick and choose what they want.
Things that come to mind are:

Depth of field
Screen Space Ambient Occlusion (not sure if RV4 supports this)
Motion blur

HDR would often go under PP, but that already has its own deal.

totally agree...i played this for ...wait for it...30 secs, just cant do motion blur makes me feel ill, any game i have that has it i turn it off in the options. i haven't come across a game that i own that doesn't let you stop it when it is featured ...i feel this needs a lot more coverage, so lets get all our mates who have the game to report this as it is a fundamental flaw!!

For me this would be very needed since it makes my eyes hurt real quick so it needs to be able to be ticked off without removing other post-FX stuff which make the game look nicer.

Also, the game tends to overkill with the bloom. It either needs to be scaled back, refined, or just removed.

To clarify after the following comment (seemed clear to me)

The motion blur effect is particularly evident when using TrackIR due to the continuous movement of the view.

clearly this is a motion blur issue, not a TrackIR issue

This is not the place for that, you should have read the manual or the forums.

The bloom is HDR. Make sure that is set to standard. Honestly, I don't know why the low option even exists. It looks awful and it's just HDR. If that's enough to break your performance, you've got bigger issues lol.

I'd like to be able to enjoy Depth of field and Ambient Occlusion without excessive motion blur. I do enjoy a small amount of blur, but in order to get the best of the other effects, I need to crank up the Post Processing.

Disable post-processing to get rid of motion blur.

Up-vote #0001682 for a separate option.