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Posts Tagged ‘filmmaking’

550d Video: Filming Fire

One of things that many people have really enjoyed about video DSLRs are that in many circumstances you don’t need to use lights to film at night-time. The larger sensors combined with fast lenses and adjustable ISO mean that many situations which previously would have called for using lights can now be shot without them, which means without the need to carry about bulky equipment and power sources. Unfortunately this post isn’t about one of these occasions.

Filming fire spinning is basically a bit of a pain in the ass. There are two things you need to have relatively well exposed, the performer, and the fire. Although the fire props themselves kick out some light, the difference in brightness between the two tends to be far greater than a camera can cope with. Its one of those situations which really makes you appreciate how powerful and image processing tool the human eye is. Consequently without lights (even with a DSLR cranked up to 3200 ISO and a fast lens) you either get massively overexposed flames or massively underexposed performers. Either one of these means you’ve essentially failed. In the past when I’ve made fire based films with cameras like a Panasonic HVX200 I’ve needed a set of a few redheads (850w lights) to get enough light onto the performers while retaining some level of detail in the fire to make things work. For this shoot we had one redhead, and a 125w energy-saving lightbulb, and despite a near total lack of ambient light in the location, with the highlight tone priority function enabled the 550d coped pretty well, keeping a reasonable amount of detail in the flames and lighting the performers so their movements can be clearly seen.

One thing that was quite noticeable in post-production was that the image does tend to break up a bit if graded too heavily (probably because of the relatively high ISO used). The footage from a HVX stood up considerably better because of the extra colour information in the DVCPROHD codec, which has a lower resolution (720p) and higher bitrate (100mb/s) than the footage from the 550d (1080p and 44mb/s). But saying that, the DSLR’s superior low light capabilities meant that the footage didn’t need to be tampered with too heavily (although trying to make it look less like we’d hung a black sheet up did mean darkening some of the dark greys a bit).

Overall for what is a relatively cheap camera, the 550d footage held up really well in what is a really challenging set of circumstances to be shooting, there are few other situations where there’s such an enormous difference in luminance between different parts of the same image which need to be properly exposed, and once again the results are on a par if not better than what you get from ‘professional’ camcorders which cost several times as much as a 550d and a couple of lenses. This just underlined again to me what a game changer relatively cheap video DSLR’s are, they allow hobbyists/amateurs with a pretty minimal budget to create images which a couple opf years ago simply weren’t possibly without spending many thousands of pounds.

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Last week I was lucky enough to be lent a Canon 550d (Rebel T2i in the States) by a friend so that I could have a play about with the high definition video capabilities of Canon’s latest high end comsumer digital SLR, and the results are the video above. This post is basically some thoughts on video DSLR’s based on my experience making this short.

There’s been a huge amount of interest in the developments of SLR stills cameras which do video recently from independent filmmakers for several very good reasons:

1) Chip size:

Whereas professional camcorders going from old SD favourites  like the Sony PD170 to solid state HD camcorders like the Panasonic HVX201 and Sony EX1 had 3 CCD or CMOS chips which range between 1/4 of an inch (PD150/170) through 1/3 of an inch (Canon XL1 Panasonic HVX201) to 1/2 an inch (Sony Ex1/3) the 550d and 7d use a sensor which is a 1.6x crop from 35mm. As you can see in the sensor size comparison diagram above, the 1.6x crop sensor in the 550d/7d is absolutely massive compared to the chips in dedicated camcorders, which is one of the reasons why you would expect the DSLR’s to have a huge advantage shooting in low light (more light gets through onto a bigger chip than a small one). It also means that the very wide depth of field associated with digital video whereby everything is pretty much in focus, isn’t something you’ll find with video DSLRs unless you crank the f-stop way up. This means that filmmakers get far greater control of the depth of field, allowing material in the frame but which is not the primary subject to be out of focus, drawing the viewer’s attention to the desired subject or point within the frame.

2) Interchangeable lenses: To get a camcorder with interchangeable lenses you’re looking at several thousand pounds. All DSLR’s however do this, and additionally there are an abundance of cheap old film SLR lenses to be found on ebay. Being able to gradually build up a collection of lenses to use in different situations makes the video DSLR’s incredibly versatile, allowing the use of fish-eye, macro, big telephoto and super fast prime lenses. Any camcorder for less than four times the price of a 550d and you get a lens built into the camera, and while you can add converters to make things a bit wider or a slightly longer telephoto, you don’t get anything like the breadth of creative possibilities unless you spend thousands more pounds on a special converter to allow the use of 35mm lenses.

3) Low light Shooting: In addition to the large sensor, video DSLR’s allow the filmmaker to adjust the iso in the same way that a photographer would. With the amazing feats of engineering that go into stills cameras, this means that you can shoot watchable video at up to around 3200 iso, while most camcorders shoot somehwere between 300-400. This means that you can film under streetlights without needing a bunch of lights and a power source for them. It also means that you don’t need to buy/rent expensive and powerful film lights to shoot in less than ideal lighting conditions (such as indoors). Instead of a lighting rig needing several redheads (850 watt) or blondes (2kw) and a generator to power them, a few colour balanced florescent or led lights run off a power pack or a car battery and inverter can be used to give the filmmaker creative control over lighting. However not needing to take a lighting rig out at all is perhaps the most exciting possibility offered by the video DSLR’s here.

4) Cost: Whereas the camcorders I’ve been talking about generally cost somewhere between 2 and 4 thousand pounds the 550d costs £600 for the body only or £670 with a kit lens. The 7d costs around £1k and the full frame sensor 5d can be found for £1700. While many people will feel the need to spend the same amount as the body again on lenses/rig/sound kit/etc with a DSLR, even with these additional costs you can have a filmaking setup for a fraction of what it cost just a couple of years ago. For Waves and Particles i used one lens, a tamron 18-55mm f2.8, no rig, no sound recording and the only other accessory I had was a Z-finder which I ended up not really using. Without the Z-finder that’s around a thousand pounds worth of kit to take images which are higher quality than on a £4,500 ex1. If you’re shooting music videos or any other kind of film that doesn’t need sync sound that’s a huge saving in terms of cost as well as getting a superior image.

These four points mean that at the moment most of the really exciting new possibilities for indie filmmakers seem to be coming from stills cameras?! It must however be noted that alongside the pro’s of shooting video with a stills camera there are currently some pretty big downsides

1) Rolling Shutter: The sensor in a DSLR scans across the chip, meaning that if you pan quickly vertical lines will distort as by the time the sensor has scanned across the chip the line has moved. This means the subject can appear to wobble in a manner incongruent to real life, rendering that part of your shot useless. If you intend to spend a huge amount of time whip panning around video DSLR’s aren’t for you.

2) Sound: The 550d has a fairly poor onboard mic (although I wouldn’t use the onboard mic on many cameras), and while it does have an audio input, it’s a 3.5mm jack rather than an xlr. Also professional camcorders tend to have two xlr inputs to allow stero sound, whereas the DSLR’s only have the one input. For Waves and Particles this didn’t matter as I didn’t need to record audio, there are of course many filmmaking situations where you want to be able to record high quality stereo audio as well as video. The way to do this with a DSLR is to record seperate sound onto a solid state audio recorder such as this and then sync up your sound in post production. This is a bit more hassle, and the amount of extra work will depend on the kind of material you seek to create; having to re-sync 40 hours worth of interview rushes for a feature length documentary is probably a task best avoided if at all possible, but then no-one is suggesting that video DSLR’s can do everything better than a dedicated camcorder, just that they take better quality images at a similar price point and that in many situations the negatives are unlikely to be enough of a problem so as to outweigh the benefits they offer.

5) Handling: Stills cameras are set up to handle like a stills camera, wherein the photographer rarely needs to handhold the camera still for more than a fraction of a second, whereas camcorders are designed to be used for continuous filming. Saying that though, camcorders like the Panasonic HVX201 and Sony EX1 are quite a pain in the ass to hand hold for a long period of time, and many people advocate the use of a support of some kind to improve hand held stability and comfort. Unsurprisingly you can also now buy a DSLR rig for varying amounts of money ranging from quite affordable, through to hideously expensive or of course you can make one yourself for a fraction of the price.

So how did my first experience of shooting with a video DSLR go? Well to be honest I was massively impressed. I only had 75% of a single battery to play with, so didn’t have a huge amount of time to play with different setups or to familarise myself with the camera, so I was pleased that most things on the camera are fairly intuitive. One feature which isn’t, or at least wasn’t is the way you change the aperture. Whereas Canon’s professional DSLR’s have separate control wheels for shutter and aperture the 550d has just a single wheel. This shouldn’t pose a problem while shooting video as you’d have thought that the wheel could be used for aperture and on the extremely rare occasions where you want to alter the shutter speed you could hold another button in while scrolling, however for some reason Canon have set things so that the wheel controls shutter speed and you need to press another button to change the aperture. It isn’t a massive problem, just an irritating piece of design. It could be that by delving deep into menu’s this can be altered, but with a limited amount of battery life and time I wasn’t able to explore this further.

I was lent a Zacuto Z-Finder to use with the camera which is a very expensive bit of plastic which turns the lcd screen on the back of the 5d/550d/7d into an eyepiece and magnifies the image slightly. I actually found it not to be terribly useful, although it does make the screen clearer, which does help when focusing, the Z-Finder restricts you to using the camera at eye level. Maybe this would be less of an issue for people without any kind of disability, but as I haven’t got much of a bend in my left leg at the moment, having to hold the camera at eye level was very restrictive, so more often than not I chose not to use the Z-Finder. If you have money to burn by all means grab one – they are useful – but for the price of £270, I think they’re hugely overpriced and 95% of users would do better to spend the money on lenses/tripods/sound kit/support rig.

The images the 550d creates in 1080p are absolutely stunning. There’s no other way to put it. I was immensely impressed with the image quality. The images look as good if not far better than anything you’re likely to get out of a camcorder which costs under £10K. And this is from a body you can pick up for £600. Quite frankly it puts the camcorder manufactures to shame that kit exists at this price point which is capable of producing such high quality pictures. Ironically Canon themselves still sell camcorders for many times the price of a 550d/7d/5d which shoot 1080i onto small chips and don’t let you change lenses or adjust ISO.

The rolling shutter is a problem if you want to pan with any speed – and following some of Ed’s movements made for quite wobbly images, but under most conditions this isn’t going to be a problem, just something you learn to work around. Handling wise I actually found the 550d quite good; I’m still not really able to carry much about, so compared to a camcorder like Panasonic HVX201 the 550d was small light and super portable, even for someone who is currently cumbersome at the best of times. Despite being a ‘small’ consumer DSLR, the 550d was heavy enough to hand hold relatively still, we only used a tripod for a couple of shots and I haven’t added any image stabilisation in post production either. While I could see many situations where a shoulder support would be useful, there are by no means essential for doing hand held work; much like using a support with a camcorder in fact.

Not having zebra bars is a bit irritating, usually you can set these on a camcorder so that areas that are overexposed, or at 95% exposure have stripes on them, giving you easy visual feedback as the where your white point is and allowing you to set aperture accordingly. Without this, working out what is overexposed becomes educated guesswork, and especially with the amount of light that fast prime lenses let onto the big sensor this might be an issue for some people. Magic Lantern have added zebra bars with their hacks to the Canon 5d firmware, it would be great if similar alterations were made to make the 550d/7d more exposure friendly.

I was concerned before we got going as to how hard focusing would be with the shallow DoF. Fortunately, focusing is actually quite simple, you can digitally zoom into an image, focus, and then return to a regular view with a few button presses,  so even with a fast moving subject generally focusing wasn’t too hard. To pull focus with machine like precision you could buy a follow focus unit, however again these aren’t cheap, and I found that actually manually focus pulling was hugely enjoyable and visually effective. 

Overall I found the 550d to be a joy to use and shoot with, and after this brief test I intend to buy one once I’ve managed to save up some money. For under £1000 even with a couple of lenses the 550d offers truly stunning value for money as a video camera; and that’s ignoring the fact that it’s also a very capable stills camera.

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