Shooting HD video with DSLR cameras

When Nikon introduced its D90 model as the first Digital Single Lens Reflex (DSLR) camera to shoot high definition (HD) video, it started a trend which allowed creative camera people to produce high quality footage with a stills camera at a fraction of the budget.

Unlike video camcorders, professional stills cameras are full-frame (35mm) or cropped sensor – bigger than the largest 2/3inch professional broadcast camera sensor. Added to that is the ability to put very fast (i.e. low F-Stop number) 35mm stills lenses in front of the camera. This results in an unbelievable shallow depth of field (DoF), a very common practice in the world of professional cinema.

A shallow DoF allows one to focus on the subject, leaving the rest out of focus. This isolates the subject from the background and allows the filmmaker to control where the audience puts their attention.

One way is to go DSLR and simulate a film camera using a Letus Relay lens and Letus 35mm adapter.

The decision to go with DLSR or semi-professional video equipment depends on the project. Compare time and budget. DSLRs are better suited for those who have the time to set things up properly. Without any stabilisation equipment and manual sound recording, DSLR has its limitations. If time is not critical, going with a souped-up DSLR is an attractive alternative.

Shooting from the hip is now possible when previously shooting required professional cinema equipment with a minimal crew of four (director, camera operator, camera assistant, sound engineer). DSLRs may be cheap, but talent is priceless.

It takes knowledge, talent, a lot of practice and learning from others. With more people having the ability to start shooting beautiful images we can expect an exponential growth in high quality content made for the web (even at 1080p) that looks like it was created using professional cinema equipment.

Some of the factors to consider are: 30p versus 24/25p

In order to achieve the cinematic or film look, video should be recorded the way film is traditionally made. Meaning 24p or 24 full frames per second. The frame rate in NTSC is 29,97 and 25 in PAL. Stills cameras put 30p as the standard for video. When conforming 30p to 24p, shooting is in slight slow motion giving a noticeable visual effect and audio sync problems. The Canon 7D now supports various frame rates (24/25/50 in PAL and 24/30/60 in NTSC) firmware upgrade for the 5D mark II is due.

Compression vs color

DSLR cameras recording full frame HD video require a lot of compression for recording to a compact flash card. This means that component video (4:2:2 or 4:4:4) is not available and that color grading is done on a composite signal. Heavy color grading, matte painting, chroma keying or rotoscoping can be done in post. For basic post-production color grading works on the RedGiantSoftware or the use of Magic Bullet Looks allows for fast and efficient grading.

Stability

A stills camera is built to maintain steady for about 1/60th of a second, not to record 24 frames or more per second (i.e. shooting movies). Innovation that helps DSLR-shooters to stabilize their shot include SteadyBag from CineKinetic which allows you to create stable shots even while in moving objects such as cars and Glidecam for those who like to walk. For more professional dolly shots there is GlideTrack.

Sound

The built-in mic in DSLR cameras does not feature professional XLR input. Also, it is difficult to monitor the audio by headphones as the LCD is turned off when you attach a head-set to the AV Out on the Canon 5D (the 7D has a different plug). The Zoom portable H4N recorder provides the DSLR-shooter a simple device that excels in sound recording, allowing for up to four independent channels at the same time (1x crossed stereo at the front and 2 XLR inputs for external mics). Synchronization is done in post with a reference signal, It is therefore key to keep recording sound on the DSLR for reference audio purposes. If you are editing on Final Cut or Sony Vegas, there is PluralEyes. For manual control of audio on the camera, the Magic Lantern firmware hack may be an option.

Light

DSLR cameras outdo video camera when it comes to low-level light situations although having the right amount of light is crucial to the end result. Various suppliers offer useful equipment such as the Dedo Ledzilla and Litepanel Micro.

Filters

Opening up the iris on the still camera for shallow depth of field may easily result in over exposure. Photographers may be tempted to start changing the ISO setting or shutter speed. Shutter should be kept at twice the frame rate you are shooting to adhere to the 180-degree shutter rule in cinema. Neutral Density filters from Singh-Ray can reduce incoming light from two to a full eight stops.

Viewfinder

The viewfinder on the DSLR is blocked when entering live mode so it is difficult to see detail from incoming light falling on the LCD screen. The Zacuto Z-Finder and the 720p native resolution LCD-screen from SmallHD can prove useful alternatives.

Jello effect

This effect occurs when the camera is panned or when fast moving objects enter the frame. The solution is record slowly and speed up in post. An After Effects/Nuke plugin called RollingShutter can fix this.

Editing AVCHD

The DSLR cameras record in AVCHD format using the H.264 codec. An intermediate format can be created using Neoscene by Cineform which creates wavelets to decipher images.

Recording limit

The recording limit on most DSLRs is about twelve to fifteen minutes for a single take. Unless recording a live event, most shots are usually shorter than that. For continuity’s sake it is important to record the audio properly.