PP2014 - Motion Blur



  • Hi folks,

    Just a quickie about motion blur. I've set up a three-frame animation featuring Annie performing a split leap. The motion is ok, it all looks good, I'm just wondering where in the animation I should render from in order for it to pick up the motion blur correctly... frame one or frame three? Also, not knowing anything about cameras or camera settings really, what kind of open/close shutter settings should I use for a standard image? I'm not looking to make it too dramatic, just make it look as though she is jumping. She gets slightly closer to the camera, so the focal distance will have an effect on how we see her, as I thought it would be unrealistic to have the focal distance fixed on her at all times... I just don't want to end up with a blurry, albeit arty, mess!

    Cheers folks,

    Glen.

    P.S. The camera pans a little as she moves too, to keep her relatively central in the shot. It's not supposed to look like professional gymnastics photography, but not like a kid took it either, lol!



  • @Glen85 I know not of these things but is three frames enough? Would you not want frames for the entire leap (30 maybe?)



  • No, that's overkill, as it's supposed to be a photograph, not a video. The shutter will be open and closed again in a fraction of a second, so there's no point in animating the entire movement.



  • @Glen85 said in PP2014 - Motion Blur:

    No, that's overkill, as it's supposed to be a photograph, not a video. The shutter will be open and closed again in a fraction of a second, so there's no point in animating the entire movement.

    So as to get the best results without a "blurry mess" in your still, render your motion blur shot and then a still shot, without motion blur. Combine and edit in your preferred Photoshop clone. :)



  • I'd be inclined to agree with @ghostship about adding frames.
    Rendering frame 1 will do nothing, as nothing is moving. Rendering frame 3 may have too much movement.
    Here is an example showing what I mean.

    I set up a 3 frame anim, here are the frames.

    0_1508932643351_anim.jpg

    Now, (and bear in mind I'm using PoserPro11 and Superfly on my 980ti as it's quicker on my system) here is frame 3 rendered using motion blur at the default camera shutter speed. This took about 820 seconds.

    0_1508932764102_3rd frame motion blur.jpg

    I retimed the anim to 30 frames. Here is fame 30 rendered, which took 82 seconds.

    0_1508932811291_30th frame motion blur.jpg

    I then tried retiming the original 3 frame anim to 20 frames and rendered frame 20. This took about 130 seconds.

    0_1508932861632_20th frame motion blur.jpg

    So differing looks (and times) just by changing the number of frames, and that's at real low settings with no dof either. Adding dof would ramp up times even more.

    Hope that helps.



  • Thank you for the replies, but I should just clarify something: When I say I've done a three frame animation, there is only slight movement. I have not created the entire leap from start to finish and squeezed it into three frames, as it seems you have there. Annie is stood in preparation for the jump in the previous render and, in this render, will be performing the jump, with the 'photograph' being taken mid-jump. I put her into a pose, then moved to frame three and moved her down on her Y axis, moved her arms, hair, legs, head and breasts to give the illusion of movement, but all of those movements are slight. I don't see the need to animate the entire movement from start to finish, as the camera will never see that movement, due to it being a photo, not a video.

    Let's think of snapping a racing car passing us. We are stood on a straight at a race track and take a picture of a car passing at high speed. We don't need to animate the car coming into view quarter of a mile away up the straight, then passing us, then disappearing from view over the crest and around the corner at the other end of the straight, we just need to put the car where we want it in our render, then render it moving from left to right (or right to left) a couple of feet or so and spin the wheels, as that's all the car would ever appear to do in the shot anyway, unless you have a long exposure, which I don't have here.



  • That's ok, no probs, I just misunderstood when you said a three frame anim. You could do it with 2 frames if that's the case. That's how I normally do motion pics myself. All I would do then is just render frame 3, that should do it. After all, the renders of the 20th and 30th frames are, in effect, the same as your own anim in which there only is small movement being captured.



  • Brill, that's what I was after, thank you! I've done it before, ages ago, but couldn't remember which frame I rendered, and didn't want it to look like Annie was jumping off the ground, backwards, defying gravity and winding up higher than she started, lol!