Jerky/Sticky footage with Blackmagic Pocket Cinema Camera

[John Fishback]

What codec are you using? What frame rate?

[Mike Laloe]

Thanks for responding – it’s Apple Pro Res HQ – frame rate 25.

Here’s the properties blurb…

File Path: G:\Berkut\BERKUT Black Magic\Blackmagic Pocket Cinema Camera_1_2013-07-14_1812_C0000.mov
Type: QuickTime Movie
File Size: 63.5 MB
Image Size: 1920 x 1080
Frame Rate: 25.00
Source Audio Format: 48000 Hz – 24 bit – Stereo
Project Audio Format: 48000 Hz – 32 bit floating point – Stereo
Total Duration: 00:00:05:01
Pixel Aspect Ratio: 1.0

QuickTime Details:
Movie contains 1 video track(s), 1 audio track(s) and 1 timecode track(s).

Video:
There are 126 frames with a duration of 1/25th.

Video track 1:
Duration is 0:00:05:01
Average frame rate is 25.00 fps

Video track 1 contains 1 type(s) of video data:

Video data block #1:
Frame Size = 1920 x 1080
Compressor = Apple ProRes 422 (HQ)
Quality = Most (5.00)

Timecode:
Timecode track 1 contains 1 type(s) of data:

Timecode data block #1:
Start Time = 18:12:08:00
Reel name =

[John Fishback]

Is the camera moving or panning while you see the stutter? Does it appear most on vertical edges? If so, this may be normal. A fast pan will result in stutter. The American Cinematographer Manual has charts that show the max speed you can pan through a given angle without stutter. If the camera is stationary, then something odd is happening. What shutter angle are you using? I’m not sure, but that might have an effect if the camera’s panning.

[Mike Laloe]

Thanks for your posting – no the camera was stationery and on a tripod but the subjects arms were moving. I’m not 100% sure about the shutter angle but I think it was 180. I’m starting to think it might be a problem with the memory card. It’s the recommended one but maybe it’s just playing up?

[John Fishback]

Do you see the effect just on the arms? if so, their speed might cause the stutter. It’s about the relative movement between camera and subject. It’s also possible the stutter might be an artifact caused by rolling shutter. Here’s an article rolling shutter from wikipedia: https://en.wikipedia.org/wiki/Rolling_shutter.

John

MacPro 8-core 2.8GHz, 16 GB RAM, OS 10.9.4, QT10.1, Kona 3, Dual Cinema 23, ATI Radeon HD 5870, 24″ TV-Logic Monitor, ATTO ExpressSAS R380 RAID Adapter, PDE enclosure with 8-drive 6TB RAID 5
FCP-X 10.1.3, Motion 5.0.7, Compressor 4.0.7
FCS 3 (FCP 7.0.3, Motion 4.0.3, Comp 3.5.3, DVDSP 4.2.2, Color 1.5.3)

Pro Tools HD 10 w SYNC IO & 192 Digital I/O, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec DSP Monitors, Prima CDQ120 ISDN

[Roger Poole]

Your shutter speed needs to be at least X2 your frame rate. 25fps – 1/50th or more. This will impact the exposure but the footage should be smooth.