Video look in Shrek 2

Mike Brennan · July 4, 2004

I'm interested if anyone else has seen the occasional short shot in Shrek 2 that suddenly looks like video. I have seen this before on other animated movies, it isn't new.

I put this down to those shots being created with a (comparable) exposure of less than 1/48th of a second, perhaps 1/30th. So the motion portrayal is more blurred than 1/48th.

The Shrek shots had the subject moving through a stationary frame quickly. (shreks wife getting out of bed is one example) My guess is that they used a slower "exposure" to allow fast movement through frame.

This is interesting, if animators are trading some blur to allow fast action without strobing.

There were a couple of other shots where 1/30th second type motion portrail seemed to be employed.

I'm wondering if this is planned at the animation stage or if it is a tool that the editor selects to rectify strobing if they have to speed up a shot.

If we imagine that the audience don't mind this look, how usefull would this technique be on HD

shoots?

Faster action through a stationary frame. Usefull??

Mike Brennan

chrisM · July 6, 2004

I can't comment on animation but I've got a bit of a theory regards the temporal video look, (as opposed to video contrast, color etc.)

The traditional difference between the film look and video look is the field rate vs the frame rate, (i.e. 60 fields shown once vs 24 frames shown twice). In theory, an HD camera shooting at 24P should look the same as film, but in practice it still has a slight "video" motion look about it.

I think this is because a film frame is "wiped" by the shutter at the end of the exposure time, while a video camera switches the whole frame within an instant. This means the leading edge of a moving object is very sharp on video - and this leads to a similar "look" to what you get with an interlace camera. The slightly out of focus film shutter gives a softer "end" to the frame. (hope this makes sense :blink: )

I tried a test with a Digi Beta in frame mode where I mechanically shuttered the lens, so that one field time was black. The end result was very "filmic" motion.

So, I think blur has a lot to do with the "film look", but perhaps it's the blur in front of the moving object rather than behind it?

Rob Belics · July 6, 2004

Time of exposure has no effect when using computer animation. All blur is created by the software. If blur is not created, it is not "induced" by record time or exposure. Exposure time for each frame is not 1/48 or 1/30. Frames are recorded the same as a DI would using machines similar, or maybe exactly, to the ArriLaser.

Phil Rhodes · July 6, 2004

Hi,

Sure, but all current software routinely simulates motion blur; you normally give it the frame rate and duty cycle, so the effect is exactly the same in the end. The implication here is that they're expressly doing something different - it's possible to simulate anything up to 100% duty (a 360 degree shutter) in a computer, which might make it look smoother than live action film. I wouldn't have thought that you'd get that effect by reducing the virtual shutter angle, as that'd simply make it more flickery than already-flickery film.

Phil

Mike Brennan · July 7, 2004

"Time of exposure has no effect when using computer animation. All blur is created by the software. If blur is not created, it is not "induced" by record time or exposure. Exposure time for each frame is not 1/48 or 1/30. Frames are recorded the same as a DI would using machines similar, or maybe exactly, to the ArriLaser."

Ahh virtual shutter angle was the technical term I was looking for...hence my incorrect use of "exposure" in quotation marks. I wasn't reffering to Arrilaser either:)

Some scenes appeared to have virtual shutter angles different to the norm of 1/48 ie 1/30th. The rest of my musings remains.

I'm more interested in the effect on the audience than how they do it....

Mike Brennan

harryprayiv · July 7, 2004

Time of exposure has no effect when using computer animation. All blur is created by the software. If blur is not created, it is not "induced" by record time or exposure. Exposure time for each frame is not 1/48 or 1/30. Frames are recorded the same as a DI would using machines similar, or maybe exactly, to the ArriLaser.

ya beat me to it. I thought Shrek 2 had a great use of motion blur.......like at the end, when they do freeze frames to credit actors/actresses, you can see some motion blur in those stills...especially in the shot of the princess.

Rob Belics · July 7, 2004

I worked, briefly, for Pixar and SGI years ago. Was very well read but, like a lot of things, have forgotten more than I remember about all this.

Mike Brennan · July 11, 2004

ya beat me to it. I thought Shrek 2 had a great use of motion blur.......like at the end, when they do freeze frames to credit actors/actresses, you can see some motion blur in those stills...especially in the shot of the princess.

Did the motion blurr look slightly videoish? Is so is it a problem?

Mike Brennan