DSLRs, by their very constitution, are made for taking stills. Thus when it comes to filming with them, they are an ergonomic catastrophe and any attempt to shoot handheld without support will result in shaky unusable footage. Hence an entire industry of third party add-ons has spawned to assist with shoulder mounting and hand-holding the camera. There are innumerable options out there, many of which can be substandard and awkward to use. Stick with brands such as Zacuto and Red Rock who have a pedigree in making mounts for DSLR and you’ll be happy with the results. Filmbase rent a Red Rock shoulder rig which fits the bill nicely. Another issue with DSLRs is what’s known as the ‘rolling shutter’. Due to the way the sensor reads the image, vertical lines bend when you pan quickly making buildings seem to wobble. Err on the side of slow and steady pans to alleviate this problem.
Lenses and Focusing
One of the primary attractions of filmmaking with DSLRs is the shallow depth of field they offer, often referred to as the ‘film look’. This is in part due to the very large sensor size offered by the Canon 5DmkII and 7D over traditional video cameras (full size 35mm sensor on the Canon 5DmkII versus a ½ inch chip on something like the Sony Ex-1). This huge sensor allows for great results in low light and an extremely shallow depth of field. The lack of on-camera focus peaking options can make focusing a challenge, especially when you or your subject and you are trying to work off a 3-inch LCD screen in sunlight (note: autofocusing is not an option when shooting video with DSLR). Zacuto make a viewfinder that can be attached to the LCD screen to magnify the image or you can use a good quality HD monitor, some of which have peaking options to assist with focus. A follow focus unit attached to your DSLR rig will also help you pull focus smoothly, keep track of focusing points and reduce camera shake if trying to adjust focus off the barrel of the lens. For best image results stick with prime lenses if possible and try not to shoot wide open as most lenses do not perform that well at their widest aperture. There are some great used Nikon manual focus prime lenses on the market and you could acquire a very decent set of these for the same price as a single Canon autofocus L lens.
Shutter Speed & Exposure
The golden rule for shutter when shooting with DSLRs is to always double the frame rate to get your appropriate shutter speed. So when shooting at 24 or 25fps on a DSLR, set your shutter speed to 1/50th second. If you are shooting 50fps on the 7D, set your shutter to 1/100th. This setting maintains the correct amount of motion blur in your video to achieve the ‘film look’ and is derived from the 180 degree shutter angle rule from the world of film cameras.
When selecting ISOs, choose multiples of 160, i.e. 320, 640 and 1250. The higher you go with the ISO, the more sensitive to light the camera becomes but the trade-off is noise and artefacts in the image. Going above 1250 is not recommended as the resulting images are unusable due to the amount of noise.
DSLRs do not have any inbuilt neutral density filters (ND filters) so to avoid having to stop down to f/22 when shooting on a bright day, invest in a vari-ND filter which you can screw onto your lens. This allows you to smoothly control the amount of light without affecting your desired f-stop. A few step-up and step-down rings won’t go astray either so you can use the same filter with multiple lenses with different thread sizes. Alternatively, you can use 4×4 ND filters if you have a matte box.
The factory picture profiles on the 5DmkII and 7D introduce a lot of compression and processing to your image which results in less than desirable dynamic range. To preserve more detail in your highlights and shadows and acquire an image that you have more freedom to grade in post, use a third party picture profile such as Marvels Cine Style and Technicolour Cine Style. These profiles give you a very flat image which doesn’t look great on camera but it will allow you much more freedom to grade with.
The Canon 5DmkII and 7D shoot video in a highly compressed codec called H.264. This codec is a viewing codec, not an editing one, and as such one of the first things you should do before editing is to convert your H.264 footage into Apple Pro Res 422. This advice is primarily aimed at those who will be cutting on Final Cut Pro. This process essentially involves decompressing your footage from H.264 into the much higher quality and less compressed codec Pro Res 422. Mpeg Streamclip is a file converter that will do the trick and what’s more, it’s free.
Batteries, Cards & Sound
DSLRs eat batteries for breakfast in live view mode. Come armed with at least three fully charged spare batteries and have a charger on the go to avoid running out of steam. Choose memory cards which are fast enough for video, you can’t go wrong with the Sandisk 60MB/s range.
The on-board mics on DSLRs are only of use for reference sound. To get decent sound quality, use an external recorder such as the Zoom H4N. Synching sound in post is less of a hassle these days with the Pluraleyes plugin.