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Getting around the 12 minute DSLR limit
- Thread starter liamupton
- Start date
I've tried using a 45 minute card, but it still overheats after 12 minutes, on my Canon T3i. I was told that there is some Sony DSLRs that are designed not to overheat, so I suppose you can get a 45 minute card or longer, and shoot with one of those.
Even if you can get round the 12 min limit, you're going to run into other problems. If you're recording audio on to a separate device you're going to run into drift problems (even before 12min in all likelihood). Even if you are recording sound internally, some DSLRs use different clocks for their audio and picture reference, so the same drift problem over time.
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If your using a dslr to record something longer than 12 minutes in a row then get a camcorder.. I have yet to experience when I would need to film for more than 12 minutes in a row ?
I also have the t3i which I used for 5 hours recording in the boiling hot sun, just get a reflective material and hold it over your camera or get someone to do it either way you should be ok, I was using a battery grip though so I don't know if that would help anything?
I also have the t3i which I used for 5 hours recording in the boiling hot sun, just get a reflective material and hold it over your camera or get someone to do it either way you should be ok, I was using a battery grip though so I don't know if that would help anything?
There are firmware hacks for a lot of cameras that will stop recording when the limit is reached and auto start a new clip, but basically that's it. If you had a camera with clean HDMI out you could go to an external recorder, but most DSLRs aren't clean HDMI.
This is the #1 reason DSLR are not well suited to "event" recording. In "narrative" it would be very rare for me to have a clip longer than 3 or 4 minutes. Most clips less than 2 minutes.
This is the #1 reason DSLR are not well suited to "event" recording. In "narrative" it would be very rare for me to have a clip longer than 3 or 4 minutes. Most clips less than 2 minutes.
Do you mean you shot 5 hours of video or time lapse under scorching sun? If it is time lapse, then camera circuit gets periodic rest in between the shots, but video is a different ballgame. Can you please share us the details? It will be very helpful for any such future project.
Those are ancient issues of past. Canon 5D MKII firmware 2.0.3 onwards, it shoots in proper frame rates
NTSC
1920×1080 : earlier 30 fps changed to actual 29.97 fps
1920×1080 : earlier 24 fps changed to actual 23.976 fps
640×480 : earlier 30 fps changed to actual 29.97 fps
and in PAL
1920×1080 : earlier 25 fps changed to actual 25.0 fps
1920×1080 : earlier 24 fps changed to actual 23.976 fps
640×480 : earlier 25 fps changed to actual 25.0 fps
No more sync problem.
No I'm not referring to an issue with a particular camera, I'm referring to an issue common to all digital equipment!
Let's take an example of standard HD recording, where the picture is recorded at 23.976 frames per second and the audio is recorded at 48,000 samples per second. For the audio to stay in sync with the picture, the internal clocks measuring the duration of a second for both the picture recording and for the audio recording have to stay perfectly in sync with each other. Even atomic clocks will not stay perfectly in sync with each other and to be sure, not even professional grade equipment contains internal clocks anywhere near as accurate as an atomic clock. The result is that as the duration of the take increases, so the discrepancy between the picture clock and audio clock accumulates and eventually this drift becomes a serious issue. How long before this drift becomes apparent will depend on the quality of the clock and clocking circuitry in the camera's picture and audio circuitry (or separate audio recorder) but this is likely to happen sooner rather than later as DSLRs tend to have budget quality internal clocks and clocking circuitry.
The solution to this drift problem is to run both the picture recording and audio recording from a single, common clock source but DSLRs do not provide the functionality to sync to an external clock source, so there is no solution to maintaining sync during longer takes with DSLRs.
If you are going to advertise yourself as a "university" you really need to have a good understanding of these basic digital facts!
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APE is correct. Audio drifts on long takes, period. The only way around it is to have both devices synced to a common clock which can be done with a DSLR (I believe), but it's a pretty expensive piece of gear to add.
12 min limit is a file format issue. Older windows format of FAT32 limits file sizes to 4.2gigs or something similar. That's what limits your video to 12 minutes.
If you reformat your SD card to NTFS, which does not have the 4gig limit, your Canon Operating system will not recognize it. So you will be unable to use the format in your camera.
I'm not sure there is a way around this.
Camera and recorder with timebase is of course the ideal solution but unfortunately beyond budget for most indie filmmaker at this moment. However, this is really not a huge issue as it is simple to rerender the sound with new time length without changing the pitch. With latest innovation in DAW and NLEs, the slight time sync issue in dual system is very easy to resolve. You can do it in Premiere, FCP and in almost all pro DAWs.
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This method is entirely likely to introduce audio artefacts and just time stretching/compressing the audio may still not achieve accurate sync.
Only with a dual system and only if you have recorded and maintained accurately sync'ed dialogue from the camera in the first place. AFAIK, most DSLRs employ cheap, off the shelf ADCs which includes an integrated clock, so even within the camera the audio and picture may not be running from a common timebase and are therefore likely drift during long takes. In this case, none of the tools like pluraleyes or NLEs or pro DAWs will easily be able to resolve this problem.
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Try it and you will be impressed. Artifacts generated by MP3 compression will be far worse than any such time remapping artifacts. Remember, film is an art and many of us shoot film with iPhone. In US, we lovingly call artifact seekers as "Measurebator"s. Fortunately most indie filmmakers are not
We try to do maximum with the resources we can afford.
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We never run into this issue in our narrative work because realistically a LONG take is maybe 5 minutes. I hear my audio guy talk about it however.
That's a fatuous argument. It depends on the amount of time remapping and the level of MP3 compression. For example, it's not difficult to apply too much time stretch/compression resulting in completely unrecognisable audio.
Unless something dramatic has changed with time compression/expansion software in the few days since I used it last, I really don't need to try it. I've been using time compression/expansion software by Serato, WaveMechanics, Melodyne, Waves and DigiDesign for over a dozen years, you think I'll "be impressed" by trying it again?
That's a coincidence, in the UK we not so lovingly call filmmakers who don't care that their sound is distorted or out of sync "Wankers" (a colloquialism for masturbater), small world!!
I'm not saying that drift problems are incurable. Using time compression/expansion software, along with other editing tools and methods, this problem can be solved but it's usually tricky, time consuming and doesn't give particularly accurate results. It's certainly a potentially serious problem to consider if the OP is thinking of hacking his/her DSLR to provide more than 12mins continuous recording time.
After 5 mins you are certainly getting drift but it's probably too small an amount to be noticeable. I can understand why your audio guy talks about it though. It might make an interesting test, if you've got nothing better to do one day: Leave the camera recording for 12 mins and use a clapper board every 10 secs or so, then import the video (and sound) into your NLE and see how much drift you're getting. At least you'll know if the drift is noticeable within the 12min limit and if so, at what point it becomes noticeable.
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He hits it because he records live music venue stuff as well. The feed from the board will invariably drift from the camera and also drift from the room mics if they are running to different recorders.
As someone else has mentioned, the 12min limit is more of a tax issue than anything else, though the newer DSLRs are coming out with 29.59 minute limits.
If you are not shooting events such as a concert or play then there is really no reason to be going to the 12min limit.
The only way around the limit that I have had work for me is to have more than one camera and stagger the start of the recording. During events that also works best since you dont want to always have the same angle and you would be cutting to different cameras anyways.