weird motion blur artifacts

[Mike Dominic]

Hi. I recently noticed some strange motion blur artifacts in a panning shot from an epic dragon. frame grabs are attached. the first frame shows the artifacts around the bottom of the right leg and shoe. in the second frame, the actor is in between steps, so there is less motion and it looks normal. this was shot on an 85mm lens with a pola and some ND. i am just curious what causes this. does anyone know?

 

[Phil Holland]

Need a bit more info here. What's the shutter speed and can you tell us more about the panning motion? If possible a small upload of the shot might help us see what's going on.

 

[Mike Dominic]

hi phil. this was 23.976 FPS, 180 degree shutter, and panning with the legs as the actor walked at a brisk pace. opening the images in a new tab will let you see them a bit larger.

 

[Phil Holland]

hi phil. this was 23.976 FPS, 180 degree shutter, and panning with the legs as the actor walked at a brisk pace. opening the images in a new tab will let you see them a bit larger.

Still images aren't going to help in this particular case as there's more than a locked off shot with a moving subject here. I need to analyze the motion and that requires several frames. I have seen normal blur artifacts and far crazier things due to specific types of motion. Examining several frames lets me see how the motion blur is "birthed" and developed across the contrasting movements and that might be what's going on here.

 

[Matt Ryan]

What mount were you using? A motion mount by chance?

 

[Mike Dominic]

https://vimeo.com/111460670

you can watch a few seconds of it on vimeo, or download the h.264 file if you want to see it frame by frame. this was not a motion mount.

 

[Björn Benckert]

Hi. I recently noticed some strange motion blur artifacts in a panning shot from an epic dragon. frame grabs are attached. the first frame shows the artifacts around the bottom of the right leg and shoe. in the second frame, the actor is in between steps, so there is less motion and it looks normal. this was shot on an 85mm lens with a pola and some ND. i am just curious what causes this. does anyone know?

I have done some reading about OLPF's and how they work general. From what I been reading I could think... But that would mean there is problems with polarfilters... I guessing the polarizer is the issue here but that's only me guessing. Will try to find the link about olpf technology.