Someone asked me this weekend about why my reviews of DSLRs haven't said much about video quality. Good question, with an answer Nikon won't like: it's not that great.
If you're buying a DSLR for video, think about that idea very carefully. Yes, there's a reason why professional videographers and Hollywood have jumped on DSLRs: it's a low-cost and small package way to do things that they need done. But they're making a compromise when they elect to use a DSLR over a dedicated video rig, especially now that we've got plenty of high-quality, large sensor video rigs from the likes of Arriflex, RED, and even Sony. For a few of the pro videographers that are caught in between the consumer and Hollywood and can't afford the US$100,000 or more to rig out a high quality large-sensor video camera, it's a way of doing Hollywood-style looks without the Hollywood price tag.
Another thing driving the DSLR video craze is the fact that pro still photographers discovered that they could earn more money doing video, too. Indeed, if you're on the call list from ad agencies and even many media outlets these days, you'll find that more often than not the bids ask for both still and video components. The video guys have to hire still guys to do that for them apparently, but the still guys think nothing of saying they can do video ;~). Since the video requirements often aren't set with too high a hurdle, sometimes the still guys are right: they can do it.
But don't let all that make you think that DSLR video is delivering the goods. For the most part, it isn't. To wit:
- Downsampling. The 1080P or 720P that's coming out of DSLRs is done by subsampling the sensor, and that means that artifacts are most definitely an issue. I've seen a large sample of them on every Nikon DSLR video implementation to date. Thin, near horizontal (or vertical) lines tend to have "breakage" on them due to sampling, for instance. Canon's 5DII has a large moire issue with video sub-sampling. By way of comparison, the Panasonic GH-2 has a mode where you can directly sample adjacent pixels (which is a crop), and the quality is astonishingly high. If you need telephoto video, the GH-2 is a no-brainer.
- Compression. While there's no specific "broadcast standard" (after all, many news networks are running cell phone videos submitted by viewers), it's commonly understood that networks aim for about 48Mbps in the video master. The best DSLR videos of the bunch manage about half that. The worst are one-quarter that or less. Since the compression is usually baked into the imaging ASIC, there's no real way to increase that, though the Panasonic GH1 hacks can get you closer. On the Nikon DSLRs, you're stuck with what Nikon gave you, which is pretty bad Motion JPEG on all the earlier DSLRs and better on the D3100 and D7000. But not "broadcast quality" IMHO.
- Audio quality. Even though the D7000 records at a CD-quality sample rate, the microphone (internal or external) has to go through the D7000's pre-amps, which are decidedly low quality. Moreover, you're got very little control over the levels, so most people end up using external pre-amps, too. Still, what gets recorded by the camera is lower quality than the same thing from my standalone dedicated digital recorder. Which means, of course, that I do the Hollywood thing sometimes and record audio separately from video, then combine them later in post.
- Rolling Shutter. The jello and leaning problem on fast motion is minimal but still present on the D3s and D7000, excessive on the D3100, and in between on the D90, D300s, and D5000.
- Missing formats. At a minimum a video camera should support 720P/1080P at 24, 25, and 30 fps, and preferably also 60 fps. We seem to get different subsets of that on different cameras, for reasons that are totally unclear. What Pentax is thinking doing only 25 fps is bizarre to contemplate.
- Terrible autofocus. While Nikon touts that there's autofocus in video on the D7000, it's not usable in my opinion. And the other Nikons? Not even worth trying. Every Nikon engineer should be forced to work with the GH-2 and the 14-140mm lens for a week. They'd be shamed into fixing their problem.
- Limited manual control. Yes, we know the camera companies are using ISO to finesse exposure in manual mode, but not being able to change apertures during recording and not having really good control over both aperture and shutter speed for video is frustrating. You can jump through hoops to sort of get what you need now, but it's still subpar to what's desired by someone really interested in video. Nikon is especially feeling the results of using the same lens mount for over 50 years: the aperture activation arm scheme is not the best for real time aperture adjustment.
The list is actually much longer than that, but I'm going to stop here instead of boring you with small details. Simply put, we've taught an old dog how to do bird tricks, and obviously, a dog is not a bird so you don't quite get the same thing from it. But if enough people really want me to do a thorough review of the video features of new DSLRs in addition to what I'm doing with my current reviews, I suppose I'd oblige. But you might not like the result ;~).
So a couple of things. In order of best video quality to worst on Nikon DSLRs: D7000, D3s, D300s/D90/D5000, D3100. In order of best video quality and handling to worst on DSLRs I've tried: Panasonic GH2 (by a clear margin), Panasonic GH1 (with hacks), Canon 5DII, NEX-5, Nikon D7000 (a fair ways down from the best), D3s. In order of audio quality: same list in same order, except the D3s is better than the D7000.
If you really want to use old F-mount optics to capture large sensor video, in order of best to worst: RED ONE, Panasonic GH-2, GH-1, Canon 5DII, Nikon D7000, D3s. I wouldn't bother with the rest.
I've been doing a lot of video projects locally lately. I currently use two DSLR cameras when I'm doing this: the Panasonic GH-2 and the Sony NEX-VG10. If there is no light present, I'll drag out the D3s, but then I'm committing to 720P/24, which I'd rather not do. In general, I'm pleased with the results I get out of the GH-2, I can live with the results I get out of the NEX-VG10, and I don't drop down to the Nikon DSLRs unless there's a clear reason I have to (e.g., the low light capabilities of the D3s).
Do I care if Nikon does better video with a D400, D800, or D4? No. I can't see them topping what I'm getting out of the GH-2, nor do I want them to spend the engineering effort to do so, as there are still hundreds of things I'd like them to do on the still side. Will Nikon try to improve video on the D400, D800, and D4? Of course they will. They've committed themselves to go down the dead end alley (for them) and aren't about to stop until they butt their heads up against the final wall they can't get through.
Negativity Reversal Initiative Number One (NRINO): a few of you think that I can only write negative things (apparently you're not reading everything I write ;~), so I'm implementing a new policy. Every time I come down hard on Nikon I'll find something to praise ;~). Here's today's NRINO: Nikon's Intervalometer function (D7000, D300s, and D3s all have it) is great for time-lapse videos. As a bonus, the Resize function on the RETOUCH menu allows you to downsample to 1920x1280 if you wish and to batch the entire interval set, which gets you quite close to 1080P framing (still would need some trimming). But do yourself a favor and drop your original Image Size down to Medium or even Small (but keep the JPEG compression quality high). This allows you to run intervals at mind-blowing ISO levels, even on a D300s.