[Henrik Duncker]

Hi David,

I used as long (or almost as long) exposure times as the camera allows for a given frame rate. I do recognize that using a 1/60 shutter speed with 60fps may not be ideal and can cause too much of motion blur. Unfortunately I did not make notes on the shutter speeds used when I shot the actual footage I started working with, nor did I make notes on my first pendulum tests. However I certainly did not use too short shutter speeds, wanting to avoid strobe like effects. Further, I recognize that when working with slow motion effects (like in my case) the shutter speed / frame rate relation may need extra consideration.

Nevertheless, I have now got enough feedback from people who can’t see any frames dropping (stutter), so that I can quite safely assume that the camera is fine, and so are the files that I’ve produced. What remains is the question why my computer is giving the hick-ups. System upgrade to Yosemite and possible further talks with Apple are the next steps.

Anyway, thanks for the input. I will take the linked pendulum test offline as it won’t serve a purpose any longer.

Henrik

[Henrik Duncker]

Hi Kevin,
Changing the extension from .mov to .mpg only causes QuickTime to start a conversion process if I try to play the movie (i.e. it wont play the file as such).
Best
Henrik

[Henrik Duncker]

No, it is on external FW disk.
But I also have tried to play from the start-up disk and several other externals while looking for a cure.
Henrik

[Henrik Duncker]

Yes David, I’ve fiddled with similar pendulum tests: The issue introduces itself with all camera fps settings (25, 50, 30 and 60 fps) and resolutions (720p and 1080p), no matter if the footage is slowed down or not.
Last night I wanted to rule out a potentially faulty Nikon camera. The pendulum test with a Panasonic Lumix GF1 gives me the same problem. Lumix gives H.264 as well, and its frame rate seems to be fixed at 30fps.

About the pendulum tests:

I’ve reinterpreted the footage slower in Premiere, also tested the route of converting to tiff sequence (thus leaving behind any frame rate data) and importing back to ProRes422. Also, a colleague at the film university used a special software to change the frame rate directly in the original footage’s metadata. Nothing seems to solve occasional frame dropping.

As you mention David, slowing down the footage to 50% seems to make jittering more evident. However, I feel that this is only because skipping over a frame or two is easier for our eyes to notice at 30fps or 25fps than it is at 60fps.

[Tero Ahfors] on this forum pointed out that my Premiere’s frame dropping indicator does not give a warning: “If it’s not dropping frames then the issue is probably with your monitoring or monitor refresh rate.”

I guess this is narrowing down to monitor / display card issues.

Here is a Vimeo link to a pendulum test with playback problems.
https://vimeo.com/118794321
password “pendulum”

Having just watched it in Vimeo, I saw some 5-7 definite spots with dropped frames (i.e. suddenly the swinging teacup jumps clearly ahead of its otherwise consistent pace. During the second watching it happened tens of times, however not as dramatically, and not in the same places.

It is a 25fps sequence from Premiere Pro. As I already had problems with original footage imported directly to Premiere, my colleagues suggested experimenting as follows…

The first half of this file is produced
1. Nikon H.264 @ 60fps
2. with Media Encoder: export as tiff sequence
3. tiff sequence imported to QuickTime7 as being 25fps
4. exported from QT7 as ProRes422 @ 25fps
5. imported to Premiere and double checked that clip is correctly 25fps and put on the 25fps timeline.

The latter half is produced
1. Nikon H.264 @ 50fps
2. imported to QuickTime7
3. exported from QT7 as ProRes422 @ 50fps
4. imported to Premiere, interpreted footage as 25fps and put on the same 25fps timeline.

[Henrik Duncker]

Thanks Tero. I will keep sending the files to other MBP users, to find out if Apple laptops in general have trouble with playing video smoothly. I think yesterday we excluded possible Retina-display related causes by running it on a non-retina iMac, again with frame skipping.

Henrik

[Henrik Duncker]

Hi Tero. No this is not about shutter speed. I’ve used the slowest shutter speed the camera allows for a given frame rate, exactly to avoid that stroboscope type jittering. Instead I came up with this peculiar issue of occasional random dropping of 1-3 (my estimate) frames at a time. The dropped frame indicator is on in Premiere Pro but it gives all but green light. With the help of a professional we tested the footage also on another computer running Avid MC and a multitude of other software: same issue.

Henrik

[Henrik Duncker]

Thanks David. Could I perhaps ask you to try one step further: if you could slow down the footage to exactly 50% (interpret as 29,97) and see if that might make skipping more evident – or if it’s till nonexistent.

I’m so confused as it’s been tested here on two different MacBook Pros, on an iMac as well as an ordinary MacBook, also by playing the footage from various other hard drives.

My own set-up is:

MBP late 2013 model, quad core
2.3 GHz Intel Core i7
16 GB 1600 MHz DDR3
NVIDIA GeForce GT 750M 2048 MB + Intel Iris Pro
500 GB internal flash drive (of which 200-250 GB free)
External LaCie FW800 hard disk (with all project files there)
OS X 10.9.5

Henrik

[Henrik Duncker]

Thanks David, but as mentioned I’ve done that already.
H.264 > ProRes > import to Premiere – no cure
H.264 > png sequence > ProRes > import to Premiere – no cure
H.264 > TIFF sequence > ProRes > import to Premiere – no cure
H.264 > TIFF sequence > import to Premiere – no cure
H.264 > png sequence > import to Premiere – no cure
etc.

Henrik