The New World of Video: Part Two

19Jul12

A few blog posts ago, I commented on how digital SLR cameras with video capability have become popular choices for videographers wanting a more “cinematic” look for their productions. For filmmakers with a limited budget, these cameras can provide high quality footage at a low price. Even for Hollywood directors with enormous budgets, these low-cost dSLR cameras are finding uses as “crash cams” and for filming in tight quarters.

In planning for a recent overseas trip for HMML, it was decided that in addition to still photographs, video footage of our various digitization projects was needed. Not wanting to carry around two camera systems, I decided to try using a Canon 5D Mark II dSLR for video as well as still pictures. I’m quite familiar with this camera model (HMML uses these for manuscript photography), so I figured it wouldn’t be too difficult to learn how to use its video capabilities.

I’m not a videographer by any means, but I was able to get some good useful footage that we can incorporate into future media projects. Having worked with videographers years ago, I can also offer some opinions about how this new technology compares with more traditional video and motion picture systems. Here are some of my thoughts.

Image quality is excellent, even in low light

I remember working with a professional videographer in the 1980’s, creating product promotion and training videos. One of the things we were always struggling with was getting enough light to create a good clean video signal. It was crazy how much light we needed to get simple studio shots―one time, one of our lights actually set a diffusion scrim on fire! Shooting video in a dark environment produced murky, “dirty” video that didn’t hold up well in the editing process.

In contrast, footage shot at ISO 6400 with the Canon camera is remarkably good. There is some noise, of course, but compared to what professional-grade video cameras of a few years ago could do, the Canon is quite surprising. At ISO settings from 100 to 1000 or so, the image quality is simply wonderful, exceeding the visual quality of cameras of 20 years ago that cost tens of thousands of dollars.

For video, the ergonomics are poor

For the trip, I had brought a good compact video tripod and ended up using it for nearly all of the video I created. Hand-holding the Canon for video really doesn’t work. Ergonomically, an SLR camera is designed to be held with two hands with the camera pressed against the photographer’s forehead as he or she looks through the eyepiece. This provides a steady three-point support for the camera and allows a skilled photographer to capture images at a relatively slow shutter speed if need be.

When shooting video, things are a bit different. The camera’s optical viewfinder is of no use; the user must look at the camera’s rear LCD display to see the video being shot. This means having to hold the camera about a foot in front of your face while filming, which isn’t steady enough to get good footage (at least I’m certainly not steady enough to do it). I was able to get some usable video while shooting “freehand” by resting my elbows on a table and steadying the camera that way. Professionals generally equip cameras like this with elaborate “rail system” support rigs; these work great but can cost as much as the camera body itself.

Canon dSLR outfitted with cinema-style accessories. From Wikipedia

Get a microphone

The Canon camera has a built-in microphone for recording audio, but it’s not very good. It can be useful for picking up “ambient” sound, but it also picks up lots of wind noise. I brought a small shoe-mountable “shotgun” microphone that provided much better sound quality. I also had an extension cable for the microphone, which allowed me to put the small directional mike closer to the subject for recording interviews and such. It worked quite well.

If you really want to get the best possible audio, a separate audio recorder that uses professional-grade XLR input jacks is probably the way to go. The separate audio can be synchronized with the in-camera audio track during post-production. You don’t even need a clapperboard anymore!

You have to be careful with your exposure and color balance

For still photographs, the Canon can produce a “RAW” image file (discussed in an earlier blog post) that can be manipulated considerably in post-production. The amount of image information in a RAW file allows the user to modify brightness, contrast, and color balance to often-extreme degrees. This isn’t the case with video produced with the Canon camera. The video output from the Canon is compressed H.264 MPEG4 data. It’s more akin to the JPEG images that the camera can be set to produce for still photos. It’s compressed, 8-bit-per-channel data that has the lightness and color balance of the shot “baked in.” In post-production, attempts to salvage clips that are under or overexposed, or need significant color adjustments often result in noticeably degraded imagery.

Getting the perfect exposure can be a challenge. Attempting to evaluate the exposure settings on the LCD display can be tricky, especially when shooting outside in the blazing sunlight of southeastern Turkey and Iraq. The first thing I did was to disable the ambient light compensation for the LCD because it tends to show you a false representation of the brightness of the scene depending on the brightness of the shooting environment. I also found myself looking at the histogram displays for the scenes I was filming to check for blown highlights, which aren’t fixable in post-production. On some high-contrast scenes, I still struggled a bit with overexposed highlight while trying to get sufficient tonality in dark areas.

Lenses for still cameras often aren’t ideal for cinematography

An appealing aspect of being able to create video using one’s SLR is that a vast battery of optics is available, often at very low cost. In use, however, one finds that lenses for still photography have attributes that make them less useful for cinematography.

Take zooming, for example. A cine lens has to be able to smoothly zoom in and out and hold focus on a given point throughout the zoom. Many still zooms do not hold a consistent focus point throughout their zoom range, and some have zoom controls that aren’t smooth enough to produce a nice cinema zoom effect. Video camcorders generally have a very smooth multi-speed power zoom control that makes precision zooming easy.

The aperture control on a still camera lens is usually “clicked,” that is, it has distinct landing points at certain settings, usually at one-third stop intervals. Cine lenses are unclicked so that a smooth fade-to-black or fade-to-white can be done. With a typical still camera lens, attempts to do this result in a sort of “stepped” fade effect, which doesn’t work.

Still camera lenses tend to subtly change the size of the image when they are focused at different distances, a phenomenon called “breathing” in the lingo of the cinematographer. It can change the framing of a shot as the lens is focused from near to far or vice versa. Lenses designed for cinematography usually exhibit little or no breathing.

Another difference between cine and still lenses is focus throw. Autofocus still lenses tend to have very short throws (my main zoom lens has less than a quarter turn) from closest focus to infinity. This is deliberate; it allows the autofocus motor to focus rapidly. In movie mode, though, manual focusing is needed, and the short focus throw makes for a less precise action. Things go out of focus fast with very little rotation of the barrel.

All these things make you understand why prime (non zooming) lenses designed specifically for cinematography cost thousands of dollars each, and professional cine zooms are in the same price range as new cars.

They’re a strange, sort of “in between” motion-picture technology

Again, I’m not a professional videographer or cinematographer. The footage I shot with the Canon on my trip will likely either by presented on the web, embedded in Powerpoint presentations, or incorporated into a video presentation along with footage created by other videographers using regular high-definition camcorders of various levels of sophistication.

For someone needing to get stills and very high quality video from one machine, it works well enough. For “point and shoot” video destined for webcasting and such, a regular HD camcorder is certainly more convenient to use with its autofocus, great depth of field, and power zoom control. For what a Canon 5DMKII and some lenses (or one good wide-to-tele zoom lens) costs, one can get a very capable HD video camcorder from Sony, Canon or Panasonic.

For a filmmaker working on a Hollywood or broadcast movie or documentary project, these dSLRs make a good second-unit camera or crash cam, but their limitations make them unlikely to take business away from companies like Sony, Arriflex, Panavision, or Red.

For folks wanting a “filmic” look from video (low-light capability, selective focus effects) for the least amount of cash outlay, they’re a dream come true. If one works around their limitations and invests in some accessories to make them easier to work with, cameras such as the Canon are indeed opening up a new world of digital “filmmaking” to many more people. We’ll be seeing some interesting productions coming from folks using this technology. Some of them might be from me.

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One Response to “The New World of Video: Part Two”

  1. That is a really good tip particularly to those fresh to the blogosphere.

    Simple but very accurate information… Many thanks for sharing this one.
    A must read article!


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