PDA

View Full Version : Rolling shutter demo 1080/24p vs 720/60p



Hunter Hampton
05-01-2009, 08:18 PM
I know a lot of people were wondering about this:

http://vimeo.com/4438472

The 1080/24p mode does seem to have a slower rolling shutter than just shooting 720/60p and dropping it on a 24p timeline.

Kholi
05-01-2009, 08:24 PM
Great test, Hunter.

Question: OIS on or off? Or with a different lens?

Asking because I also noticed less jello with the OIS off, but I dunno if you're getting the sme results.

Thanks man!

Pirata
05-01-2009, 08:25 PM
awesome! Great to see it so minimal!

Ian-T
05-01-2009, 08:48 PM
I wonder why more CMOS cams don't employ that same method? That makes sense though...recording more frames per second then extracting what you need out of it. I also wonder what type of affect that will have on camera flashes?

Hunter Hampton
05-01-2009, 08:51 PM
Kholi- I think I had the OIS off, not sure though.

Daniel L.
05-01-2009, 08:58 PM
I wonder why more CMOS cams don't employ that same method? That makes sense though...recording more frames per second then extracting what you need out of it. I also wonder what type of affect that will have on camera flashes?

They do. Dropping every other frame is a common technique to remove rolling shutter distortion... For example, its employed by the SI-2K. Among other cameras that are capable of such frame rates...

Err.. That's if I understood what Hunter is doing correctly...

Edit.. Just to be clear, it won't remove the distortion completely. Just helps significantly reduce it.

ryansheffer
05-01-2009, 10:01 PM
I am very happy with what I just saw. I was not bothered at all by either of those clips.

PappasArts
05-01-2009, 11:53 PM
Very nice to see. Thanks Hunter!

j
05-02-2009, 12:12 AM
That's useful.

PaPa
05-02-2009, 05:01 AM
wow , thats really great! jello is almost gone completely.

Ian-T
05-02-2009, 07:58 AM
I wonder if this method would have helped that motorcycle footage we've seen? Seems like a very useful tool. You just choose the proper setting for the type of scene. For example...all driving and slow motion scenes could be shot with 720/60p while mostly static/tripod shots could be usd in 1080/24p.

mattsand
05-02-2009, 08:09 AM
very cool. it's not quite the same issue as dvcpro tape though, where the actual 24p frames are recorded at the correct time and simply padded on tape. converting 60p to 24p will introduce some time errors that can cause jerkiness, it's how the sony z1/fx1 does it if anyone remembers that debate. shooting 50p for 25p should work perfectly however.

/matt

Solomon Chase
05-02-2009, 09:06 AM
For normal speed shots, you could shoot 60p, throw out every other frame making it 30p, then conform to 24p. This would produce a smooth frame cadence, with only a slight slow motion effect.

One thing to keep in mind, doubling the FPS and throwing out every other frame cuts your light sensitivity IN HALF. That's probably one of the reasons Panasonic decided against it for the GH1.

USLatin
05-08-2009, 04:27 AM
Very nice. Thank you for posting it.

joe 1008
05-08-2009, 08:10 AM
very cool. it's not quite the same issue as dvcpro tape though, where the actual 24p frames are recorded at the correct time and simply padded on tape. converting 60p to 24p will introduce some time errors that can cause jerkiness, it's how the sony z1/fx1 does it if anyone remembers that debate. shooting 50p for 25p should work perfectly however.

/matt

Don't worry. If the Varicam produces smooth 24p with a pulldown from 60p so will do this little wonder.

Modified:

Not sure anymore, found out that the Varicam records true 24p...

Barry_Green
05-08-2009, 06:35 PM
No, the Varicam never records true 24p, but it also doesn't do what this camera does either; the varicam uses frame duplication (not field duplication) to make its 24p footage.

The varicam images 24 frames per second, but records 60 frames, so pretty much the opposite of what's being talked about here. With the GH1 you'd be talking about imaging 60 frames and blending them down to 24. With the Varicam it's actually imaging 24 frames, but (due to the restrictions of tape) it has to record 60 frames, so it duplicates in a 2:3 pattern.