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overheating and interviews
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[Bob Cole] “… the AVCHD codec is a concern.”
Did they say what their concern was?
AVCHD has been around for a while. Most modern computers and editing software can work with it just fine. AVCHD is based on H.264, the compression technology used by Canon DSLRs & many video cameras.
FCP users typically transcode AVCHD to ProRes on ingest, and other editing apps either transcode it, too, or work with it natively.
The GH2’s compression encoding is much improved compared to the previous GH1 model. Among other things, GH2 AVCHD video now includes B-frames, which improves quality.
The GH2 typically records fewer CMOS sensor aliasing & moire artifacts compared to most other popular DSLR cams.
Also, the GH2’s CMOS rolling shutter “skew” artifact performance is as good or better than the GH1 (hacked or not) & other DSLRs. In some operating modes, the GH2’s skew performance is significantly better than the GH1 and other DSLRs. This has been verified by 3 different testers commenting in this thread (including correctly-done test videos):
https://www.dvxuser.com/V6/showthread.php?232220-Gh2-skewThe above are some of the reasons why GH2 1080p24 AVCHD recordings @ 24mb/s can look remarkably good for such a relatively inexpensive camera.
Cheers.
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Peter –
Thanks so much for your insight into the Panasonic DSLR.I record live concert events in excess of 2 hours in length (classical concerts without ability to cut the camera off at regular intervals). It makes for interesting and painful post production sometimes, but the biggest problem I’m having at the moment is the availability of cameras to do this kind of work. DV cams limit me in recording time and the occasional failure of tape. Hard Disc recorders have been a bit of a pain (both logistically for external HD cam systems and due to size and other considerations). At the moment, I’m using smaller Canon handheld solid state cam-corders (prosumer variety).
Yesterday, I went to the Sony Style Store and looked at the A33 as a potential new platform. My wife shoots with Konica Minolta and old-school Minolta DSLRs and SLRs, so I’ve got a stock-pile of fast lenses to choose from. The sales clerk told me I could record any length video – it was only dependent upon the battery and size of removable media. I bought one on the spot!
Needless to say, when I went to record Christmas morning this morning by setting the camera on a tripod over our shoulders, I was quite dismayed to see the camera shut off after about 10 minutes of recording repeatedly!
So, shame on me for not doing more research, but it turns out that’s a pretty hard-and-fast limitation o the A33 (up to 29 minutes under certain circumstances).
Needless to say, the A33 is going back to the store ASAP.
However, on the other hand, I have a small Olympus PEN camera (The EPL1 – micro 4/3s system). Ironically enough, my wife bought me a 40-150 (80-300 35mm equiv) for it for Christmas and was upset that I had bought the Sony just yesterday. Well…based on your right up, and the failure of the Sony, the Olympus and thus the Panasonic (thanks to the interchangeable lenses!) may be the winner! The Olympus is only capable of a 7 minute record time, but if I can get a couple of the Panasonic bodies and use some of the lenses I already have, this would be a HUGE win-win!
Just out of curiosity, do you have any sample videos of raw video footage (or know of any) that may display how the camera handles high dynamic range, compression, motion, etc.?
Thanks so much and happy holidays!
Jeremy
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The Nikon D7000 records for 20 minutes per clip… I would think that would be enough
Richard M. Harrington, PMP
Author: From Still to Motion, Video Made on a Mac, Photoshop for Video, Understanding Adobe Photoshop, Final Cut Studio On the Spot and Motion Graphics with Adobe Creative Suite 5 Studio Techniques
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[Jeremy Cucco] “… do you have any sample videos of raw video footage (or know of any) that may display how the camera handles high dynamic range, compression, motion, etc.?”
Relatively speaking, there aren’t many “raw” (compressed camera-original) video files online because they are so large compared to versions of the files highly-compressed for web viewing.
However, a properly-shot compressed web video can sometimes give a very good indication of a camera’s capability. For example, if you haven’t already seen it, refer to Emmanuel Pampuri’s GH2 video here:
https://forums.creativecow.net/readpost/280/4370Emmanuel’s video contains quite a range of exposure levels, camera & subject motion, lighting, outdoor & indoor scenery, and about as much skin as a family-oriented venue such as the COW will allow. 🙂
As noted in the above post, Vimeo members can download a somewhat less-compressed version of Emmanuel’s edit, too, which further hints at what the GH2 is capable of.
I’ve started uploading some very brief camera-original GH2 “.MTS” files of my own to Vimeo, but I might not have exactly what you’re looking for quite yet. My Vimeo channel is at:
https://www.peterdv.comAlso, as I noted earlier in this thread, an NTSC GH2 can record AVCHD 1080p24 video essentially without limit. A NTSC GH2 will continue recording until the memory card is full or the battery dies. A European PAL GH2 is limited to recording AVCHD 1080p24 clips up to 29:29.
When recording very long takes, you might choose to use Panasonic’s optional GH2 AC adapter instead of powering the cam with a battery.
Note: The makers of “consumer” video cameras (including the GH2) warn that a power failure during a recording may result in an unusable clip. To help guard against this you might, for example, use a UPS power supply together with a camera’s AC adapter. Or, stop & start the recording periodically — or record with 2 cameras with “offset” start times — to help insure successful recording of unusually long continuous takes. YMMV.
Cheers.
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[Peter DeCrescenzo] “Note: The makers of “consumer” video cameras (including the GH2) warn that a power failure during a recording may result in an unusable clip. T”
That is a great note of caution! I had never thought of this potential problem with running a non-tape camera off AC. Thanks Peter.
Is this true of most DSLRs? – or, for that matter, is this true of most video cameras which record to cards rather than tape?
Just what we need to add to the kit: heavy UPS units.
Bob C
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Just to be clear, the caution I mention concerns a complete power failure, as opposed to the camera’s internal battery becoming depleted while recording a clip.
Most cameras will end a clip recording gracefully when the cam’s battery dies, or at least warn when the battery is about to expire.
But it’s when running on AC that a recording clip can be lost as the result of an AC power failure. Likewise, pulling the battery out of a cam while it’s recording will likely damage the clip.
Both Panasonic & Sony warn about this in the docs for their AVCHD consumer memory card cams. I just checked, and the user manual for the Canon 60D and Nikon D7000 contain similar warnings.
I suspect there may be some variability in this. That’s why I put the “YMMV” at the end of my previous post. Subject to your own testing, etc.
For what it’s worth, I just shot a test where I aimed my GH2 at an CU of a television screen displaying an American football game, turned off the cam’s LCD (so only the EVF was on) and started it recording. I started with a fully-charged battery. As expected, with an 8GB SDHC card the GH2 recorded for more than 45 minutes and then stopped recording when the card was full. Playback appears “perfect”. The battery indicator still shows a “full” charge. The camera is only very, very slightly warm. Probably, with a higher-capacity SDHC card, a GH2 can record for much longer on a single battery charge, subject to your testing.
On a related note: Panasonic distributes a software utility for repairing “damaged” _AVCCAM_ clips for their “pro” video cams. I don’t know if this utility can also be used on AVCHD clips, regrets. I also don’t know if Canon, Nikon or 3rd parties offer software for repairing damaged clips. I’ve seen utilities for recovering erased clips, but I haven’t researched what’s out there for fixing clips damaged by a power failure.
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[Peter DeCrescenzo] “Did they say what their concern was?”
Their concerns about AVCHD were “quality” (data rate) & “confusion” (multiple flavors). Thanks for your clarification about the evolution of AVCHD. Those concerns about AVCHD might be based on some earlier versions.
There is so much anecdotal and subjective discussion about codecs. There must (or should) be a website with side-by-side comparisons of the current codecs from different brands, as well as recordings from external devices like the KiPro and Nano Flash, would be informative.
Trade shows commonly feature line-ups of cameras and still lifes or models, along with nice big monitors which show the detail and color the company’s cameras create. Nice, but I’d rather see playback of recordings made by those same cameras, interwoven with the live views on the trade show floor.
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The 7D was the only major issue I saw that only after keeping the LCD on between takes for long periods.
The LCD and the twin Processors is what makes it act overheat faster than a 5D MK II, (what Canon told me over the phone)
Since, the firmware update that addressed the overheating issues, and turning off the LCD if not shooting.If you are not using the camera for more than 3mins shut it off. I rather burn battery by switching the camera on/off then having an overheat issue.
*Production*Post-Production*
Apple Certified Instructor (Final Cut Pro 7)
“Semper Fi USMC” -
I use a 7D and do long interviews (32 gig card) never overheated and I shoot in Arizona. I always use a “battery grip” and never use the internal battery. When batteries drain they generate heat, no vents on the camera means the head adds up inside the camera causing premature shut down. When the batteries are on the outside of the camera body the heat stays outside as well! There are battery adapters with a cable for an external battery if you do not like the 2″ rise the battery grip mandates. I prefer the grip.
M
Malcolm
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