solution for dropped/frozen frame issue

[egproductions]

I believe i've come to the conclusion as to why people have been getting dropped frames on their cameras. The issue has nothing to do with the camera but rather the CF card. The reason it is thought that it's a problem with the camera is because certain settings on the camera can contribute or cause the drop frame issue because these settings increase the overal datarate of your video and certain CF cards can't keep up.

I stumbled on this conclusion by doing some tests on compression and confirmed the results by running some additional tests.

Heres what I'm talking about:

Four things contribute to increased datarate:

• Recording audio - when audio is disabled you are able to record a longer clip as compared to a clip shooting the same static image with audio enabled. THis means that the extra data available is not being dedicated to the video but rather allowing for a reduced overall bitrate uping your recording duration.
  
• High ISO settings - the higher the ISO the higher the datarate of your video. This holds true for still photos as well. The higher the ISO the less amount of photos you are able to take and then less time you are able to record in a single 4GB file.
  
• 30P - when you are shooting 30P you have a 20% higher datarate as compared to 24P. Contrary to claims of a lower compression or higher bitrate when shooting 24P, when you shoot at 24P you are able to record 20% more in a single 4GB file.
  
• Movement - the more that changes from frame to frame the more your datarate increases.

The test to confirm:

I own 3 8GB sandisk extreme IV CF cards. No matter what I throw at these cards I rarely experience a drop frame. When I placed a lexamark 133x card in my camera I was able to record just fine but if I either enabled audio, had a high ISO or shot with 30P I started experience the occasional drop frame when I would do a fast camera motion. This seems to be consistent with what people like myself where experiencing. People have observed that lowering the ISO can sometimes help with the issue. People have also said that when they are zooming or do a pan they notice the drop frame issue. This substantiates my results that the more movement the higher the datarate.

The solutions:

• Get a fast enough CF card
• disable audio if you are recording audio off camera
• lower your ISO
• shoot at 24P
• avoid crazy movements

 

[Bokes]

This makes sense.
When I experienced drop frames- I was running a high ISO at 30p and trying to record my 2 year jump around the bed like a loon. I was also panning the camera quite a lot.
I now have a much faster 24mm 1.4 lens and shoot 24p - so no more high ISO's and not a single dropped frame.
The 2 year old is still a loon.

 

[Sadaiel]

I experience dropped frames. I tried several cards. It happens with Lexar 300X and Sandisk Extreme III 30 MB/s too. I suppose 5D data rate is 6/7 MB/s so a card which is 30 MB/s is fast enough. Dropping frames happens some times. Moreover in LOW LIGHT with high iso. In high with high iso, it's much better.

I notice some times that color changes while camera shooting (I use it in ALL MANUAL) without any auto option is on. I think some part of this camera in video mode is WORKING in AUTO mode, while you are in M mode with ALL manual settings.

I see file size is quite the same in 24/25/30, being a little, little, higher in 30p. So we can say in 24/25 mode single frames are less compeessed. Slight difference, in any case.

Ending: dropped frames happens when moving camera, even very smoothly, in low light scene, with underexposure, and high iso (from 2000 and above). If in these situations you experience dropped frames you can shoot the same panning several other times without dropping frames. Just to say that the dropping is not constant.

Ending 2: using older firmware with just 30p, 1.1.0 I had no dropped frames. This lets me think...