February 01, 2010

HD DSLRs: Still developing

Review of the Canon EOS 7D - DSLR Camera

There has been a lot of interest amongst video users in digital stills cameras recently, mainly because DSLR camera manufacturers like Canon, Nikon and Pentax have brought out reasonably priced, large sensor models that can record HD. Now, if you want a 35mm camera that can shoot HD (720p or 1080p), and take different lenses, you can buy one for less than the price of a used Sony EX1.

Canon has been the major player, especially with its 5D mark II, although that only records at 30 frames per second. We have been promised a firmware upgrade which should add 24 and 25fps - possibly due April 2010.

However, the latest Canon EOS 7D already has all the frame rates, and costs less, although it has a smaller sensor (APS-C, about 23x15mm).

It is an impressive stills camera, but while its 18-megapixel CMOS image sensor is great for still images, CMOS is not so suitable for video (although many video cameras have them). One of its problems is skew. This happens when you pan the camera and verticals don't look vertical on recording because the CMOS sensor reads line by line rather than all at once.
Some users may also notice aliasing. 

But, in the right hands DSLRs can produce stunning results.

The Canon EOS 7D It is not exactly a light camera (it weighs about 1.39kg with an 18-135mm zoom lens). Even with the image stabilisation in the lens switched on it was tricky to hold still because you couldn't hold it up to your eye (in video mode it only uses the rear LCD) so, it went on my Miller tripod and stayed there.

The 7D offers ISO speeds of 100-6,400, expandable to 12,800. My first thoughts were that any image taken at such a high ISO would be very grainy – but the camera's DIGIC 4 processors remove colour and luminance noise to give a cleaner image.

It has the usual optical eyepiece and a 3-inch LCD with 920,000 dots. I'm used to staring at LCD screens on cameras like the Sony HVR-Z1 with only 250,000 dots, so the Canon's screen was a joy to watch. Unfortunately, it is shiny and you do get a lot of reflections that are distracting when trying to shoot. If you were seriously considering buying this camera (or any of the other DSLRs) for video work you should take a look at the Zacuto Z-finder V2. It will keep out the light from the screen and, importantly, act as an extra point of contact with your body, for stability, if you are going hand held.

For video the camera uses MPEG4 AVC encoding wrapped up in a .mov file, and records onto Compact Flash cards at up to 45Mbps.

This is not a format to edit with. So, you'll need to consider software to convert it to something more edit friendly. MPEG Streamclip from Squared 5 gets consistently good reviews and is free.

In HD mode you can only record about 12 minutes of video on a 4GB card. There is only one card slot – so you can't hot swap like a Panasonic P2 camera or Sony EX. Buying a bigger card won't necessarily solve the problem, as the camera will stop recording once the file size reaches 4GB. So this might not be the perfect camera for doing that 'locked off shot'.

Recording times

4GB card
16GB card

1920x1080 HD
12 mins
24p (23.976fps), 25p (25fps),
30p (29.97fps),

1280x720 HD
50p (50fps)
60p (59.94fps)

640x480 SD.
1h 39mins
50p (50fps)
60p (59.94fps)

Stills cameras have been able to shoot video for some time – although not very well. But now the technology has improved and it is hard to deny that the results can be very good. I recommend you type 'Canon EOS 7D' into the www.vimeo.com website search box so that you can see some incredible results. If you shoot news and docs look at Guardian photographer Dan Chung's work on Vimeo and http://www.dslrnewsshooter.com

If you are a Mac user there is a lot of help getting your footage from camera into Final Cut Pro. One very helpful page is on Chris Fenwicks site. Vincent Laforet is also very helpful with advice and mentioned an upcoming new plug in (again for FCP).

The audio however is a different story. The camera does have an on board microphone which may come in handy as a guide track but it definitely won't be good enough for broadcast, it will also pick up camera handling noise and wind noise.

You really do need to record the audio on a separate recorder. Trawling through the forums it looks like most people buy the Zoom H4n. It has its own built in stereo mic, if all you need is some atmos. But, it also has two XLR sockets and can record at 48kHz, which should keep your editing software happy. With a splitter you can take an output from the Zoom for monitoring and feed the recorded audio in to the camera as a guide track for synching later. The problem is where do you put it? Maybe it might signal the return of the sound recordist.

You can swap info with other Zoom users at the Zoom forum.

If you don't want to be tethered to the recorder. Then you'd better brush the dust off your clapper board as it will once again come in handy to sync sound with vision. Funny how the more technology improves the more we rely on the old ways of working.

The evolution of the video camera has given us a body shape and layout that puts everything you need just where you want it. The iris, gain and white balance can be found without even taking your eye from its fully adjustable viewfinder.

I know many GTC members hate the Sony Z1 type cameras because of (amongst other things) their shape. But these DSLRs are even trickier to hand hold for any length of time. Unless you have the arms of a weight lifter you'll also need some sort of rig to make it feel more like a shoulder-mounted camera. Add in the cost of the viewfinder and your cheap video camera starts to look a little more expensive.

Rigs available include:
Check out their sites for demonstrations of how to use the kit and examples of user's videos.

But, if your budget is tight, start with a good old fashioned tripod. I used the camera on a weeks holiday and to keep the weight down I used my Manfrotto 561B monopod (which has feet!).

There is no peaking to help with focusing (and, even if you wanted to, Canon doesn't recommend using auto focusing when the camera is in movie mode.) There are no zebra stripes either, but there is a histogram which takes up about 1/9th of the screen. If you are used to using a shoulder mounted camera then using a DSLR will require some time to acclimatise.

Certainly, if you intend to use the camera, I recommend you download the manual (and any drivers you may need) and have a play with the camera before the shoot. For example, it took me a while to work out how to manually white balance. It isn't intuitive. 

You can also watch simple tutorials on the EOS 7D at Canon's USA site. 

Why buy one of these cameras?

Lenses, lenses and lenses. The range of lenses you can get for a DSLR is eye watering, but the prices generally aren't. So, if the director needs a one off special shot in a difficult location this camera could make you the hero of the hour.

I'd recommend you read photographer Doug Klostermann's page on "Why You Shouldn’t Buy the Kit Lens".

If one thing stands out, it is the possibility of very shallow depth of field. It seems everyone wants that film look and with 24p and a little help in post – you can have it at a relatively cheap price. The camera body costs around £1,200.

Time lapse on these cameras is stunning. If you are a timelapse newbie, start with Timothy Allen's starter guide. Take a look at the some great examples of DSLR timelapse by Tom Lowe at TimeScapes.

And if you mix timelapse and HDR (high dynamic range) photography - the results can be beautiful.

If you set the camera to record the largest still image size (5184x3456 pixels) you can import the time lapse stills into your editing software and pan and scan around the video. For a tutorial on how to do this on a Mac, Philip Bloom comes to the rescue. 

However, for timelapse you will have to spend about £100 extra on an intervalometer remote control unit to tell the camera when and how often to take each still image.

If money is tight, this camera may be all your low budget production can afford, and some people have shot incredible footage on it. It is not primarily designed to be a video camera, which means almost everything you do with it will be some sort of workaround, but considering the price, it could be worth the effort.

Would I buy one? 
I originally had a camera on loan from Canon for a week to write this review for the Guild of Television Cameramen's magazine, Zerb. I genuinely liked the camera - enough to buy it. I'm still experimenting with it and it really is essential to have the Zacuto Z-finder, which I now have on order.

Related post: HD DSLRs: nice pictures, nicer price and Canon cuts cost of HD

By Christina Fox

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