Over the last few years of filming sit-down interviews with some interesting people, I’ve been fortunate enough to be able to use a couple of different video cameras, depending on the needs of the project. Every camera I’ve handled has delivered what I expected it to deliver (mostly because I was able to test them prior to task at hand), but I wanted to explore one of the most important fundamentals of choosing the best camera for the job: the imaging sensor. Here, I’ll go through three different cameras, and why you should prefer a dedicated “video” camera when shooting video, over a video-capable DSLR.
The most prolific camera I’ve used in those years, the Canon 600D, is an excellent camera. It was wonderfully affordable when it first came to market, and has been surprisingly robust as I’ve traveled with it throughout the country and across the world. This was Canon’s first DSLR with a swivel screen, which proved to be an absolute godsend, as it allows the photographer to set up their shot for best composition, and position the screen separately to check for focus. It’s an APS-C imaging sensor, meaning that though it delivers 18 megapixels, the sensor size is 25.1 mm x 16.7 mm.
Image Sensor example of the Canon 600D
Another DSLR I used on a shoot in Chicago was the Sony Alpha 99 (a99), which is a full-frame DSLR- meaning it shoots 24 megapixels on a 35.8 mm x 23.8 mm sensor. In other words, even though the Sony has 25% more megapixels, the image sensor is physically 50% larger.
Image Sensor example of the Sony a99
Video only comes out of these cameras at 1920×1080 total pixels, regardless of sensor size. Each camera compresses the video down to this resolution in realtime, and in this image below, you can clearly see the difference that the larger sensor brings. Again, these images are both grabbed from 1920×1080 pixels.
Image Sensor comparison between the Canon 600D Digital Rebel T3i and Sony a99
Even though this isn’t a scientifically-calibrated test, these two images were grabbed from very similar videos in very similar situations, so contextually it’s how I use these cameras in the real world.
A major problem with DSLR cameras is that the internal hardware is simply not designed for shooting video, they’re designed for shooting individual photographs at a much slower pace. So in order to get 24 frames of 1080p video per second, a lot of image compression happens really quickly to deliver video files on the fly, and in a reasonably small file format. Thus, when I used a video camera with a full-frame sensor, I was floored at how much sharper the image came out to be.
Image Sensor Comparison between the Canon 600D, Sony a99, Sony NEX FS100
Again, these images were taken from a 1920×1080 video file- the end pixel count is the same across all three devices. The difference is that the final frame came from the Sony FS100- a camera whose hardware and image sensor were specifically designed to deliver video. Just as health nuts say, “a calorie isn’t always a calorie,” “a pixel isn’t always a pixel.”
Of course, in an ideal scenario, you would film at a higher resolution than what you would deliver to: film at 2K or 4K (4096 pixels across), and compress down to 1080p, ideally in post-production (a desktop computer not having to work in realtime will be a lot “smarter” in compressing images than a camera). However, this is where cost becomes an issue.
- Canon 600D: $650 without lens
- Sony a99: $2,500 without lens
- Sony FS100: $4,000 without lens
- RED One: $25,000 without lens
Cost alone is your biggest consideration for what camera you’re able to choose for your production. However, other factors need to be considered- are you traveling? A DSLR kit with lenses and a tripod are going to be a lot easier to carry into a plane than the kit required for a Sony FS100. Do you need to shoot photographs as well? A RED won’t be able to help you out, especially because they’re too cumbersome to just snap pics.
Again, it all depends on the project you’re working with. In some scenarios, you’ll find that a DSLR is perfectly capable for what you want. In others, you’ll want to spend a little extra to know you’re getting a good product.