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BMCC: Some things to consider

September 10, 2012

Let’s consider for a moment “professional” video production. By professional, I mean all video production done for hire, or as part of ones employment. This includes feature films, broadcast TV, cable & web programming & advertising, corporate marketing, sports video, educational & training video, religious broadcasts, wedding videos, and so forth. All of it.

Most professional video production is done using cameras with image sensors 2/3″ or smaller. The sensor in the Blackmagic Cinema Camera is about twice the size of a 2/3″ sensor, halfway between S16 film and the Pansonic GH2’s Micro Four Thirds (“MFT” or “m43”) sensor, as shown in this diagram on ProLost.com.

UPDATE: I’ve switched my pre-order to the new BMPC 4K model, which has a S35-size sensor

A relatively large sensor is desirable because it gathers more light (sensitivity), resulting in less noise (S/N ratio), and together with the corresponding lens design enables deep or shallow depth of field (DOF), e.g.: selective foreground, subject, background focussing. Larger sensors typically cost more than smaller sensors, and each sensor size can have certain capabilities not available in others.

The design of the not-too-big, not-too-small sensor in the BMCC, combined with its 12-bit/10-bit recording system, yields extraordinary results: Unusually-wide dynamic range of 13-stops (so it accurately renders details in bright, medium and shadow areas), tremendous color accuracy, unusually high 2.5K and true HD 1080p resolution, and very good S/N performance.

“Full-frame” (FF or 135 format) video production, such as using a Canon 5DM3 DSLR to shoot video, represents a tiny percentage of the professional video production market. Even APS-C and S35 16:9 motion picture formats are a relatively small part of the professional video production market. Although these formats have benefits, they are not an absolute prerequisite for achieving high-quality professional-looking video.

FF sensors are 2.3 times bigger than the BMCC sensor, and as a result, make it very easy to compose extremely wide-angle shots, or shots with extremely shallow/narrow DOF. Although the paper-thin FF DOF “look” is sometimes desirable, there’s a good reason why it’s not often used in most professional video productions: FF makes attaining repeatable, accurate focus on moving subjects extremely difficult. As the saying goes, “If it’s not in focus, it’s not HD.”

A benefit of the BMCC’s 2.3 crop factor relative to FF is that achieving telephoto focal lengths is relatively easy an inexpensive. For example, a 300mm FF lens becomes equivalent to a 690mm lens on the BMCC. Also, since a lens’ “speed” (maximum aperture) is unaffected by crop factor, on a BMCC a lens’ reach more than doubles with no exposure penalty. For many productions these are extremely valuable capabilities.

Unlike the BMCC, FF DSLRs typically aren’t capable of recording high-quality audio, and use flimsy unreliable consumer-grade connectors for audio and video. Professional FF video cameras, which at least feature quality audio capabilities and pro A/V connectors, cost several times more than the BMCC.

For these and other reasons, FF is impractical for most professional video productions.

FF DSLR video shooters considering switching to the BMCC may need to make some simple mental, framing, and gear list adjustments.

For example, all BMCC shooters might do well to consider acquiring an ultra-wide lens, examples of which include the Tokina 11-16mm f2.8 rectilinear zoom, Sigma 8-16mm f4.5-5.6 rectilinear zoom, or other rectilinear wide angle lenses.

The BMCC’s 2.3 crop factor relative to FF — identical for both the BMCC EF & BMCC-MFT m43 models — is typically not an issue for most video production situations. For conventional wide shots, lenses such as the Tokina or Sigma are perfectly adequate and cost <$700 US each.

As noted in a previous post, for example the BMCC can shoot scenes with a “wide” field of view equivalent to that of an 18mm lens on a S35 16:9 motion picture camera — considered “wide” in most movies & TV shows — if the BMCC is fitted with a lens such as the Tokina 11-16mm rectilinear zoom. Or, a FOV equiv. to that of a 13mm lens on S35 16:9 (crazy wide!) by using the Sigma 8-16mm rectilinear zoom.

For the BMCC-MFT model there are ultra-wide and very fast aperture manual lenses to choose from, including PL mount cine lenses, and also medium and telephoto lenses.

Obviously there are situations where a higher-quality or more capable lens is required. In which case, either shoot the scene differently, or use a different lens, or use a different camera.

As always, there’s not 1 perfect camera for every production.

With BMD’s v.1.1 release of new firmware, the BMCC-EF model now also supports in-lens image stabilization (IS), too.

Other than the above considerations, people accustomed to shooting FF video get the same benefits from the BMCC as the majority of video shooters who are accustomed to smaller sensor sizes.

DSLRs and video cameras with APS-C or S35 16:9 size sensors can cost more than the BMCC, or have far less dynamic range or resolution, or are hampered by a weak internal recording format, or have an 8-bit 4:2:0 consumer-type live video output signal, or consumer-type input connectors, and so forth. The APS-C & S35 cameras that feature very good performance or capabilities in most of these areas are typically far more expensive than the BMCC. At least APS-C & S35 cams aren’t too difficult to focus, because their crop factor relative to the BMCC is 1.6, instead of 2.3 as with FF.

Some DSLRs and traditional camcorders are less expensive, smaller, or lighter than the BMCC, and their video files more compact. But the BMCC’s video quality (both 10-bit 1080p ProRes 422 HQ, and uncompressed 12-bit 2.5K RAW CinemaDNG), plus its software bundle, are vastly better than what DSLRs and camcorders can achieve because most are typically limited to highly-compressed 1080p 8-bit 4:2:0 recording formats.

Thoughts about the BMCC EF vs. BMCC m43 models:

As a “fully supported” (pending new firmware) electronic lens mount, the BMCC EF model offers benefits to all video shooters. It doesn’t matter if most professional video shooters don’t use “auto” features such as auto-focus or auto-exposure most of the time. Most professional video shooters use auto features at least some of the time, so that makes it valuable.

Near-term, the BMCC EF model is more “valuable” to me than the BMCC m43 model primarily because the BMCC EF will be available months earlier. I’ll also occasionally make use of some of the auto features of the electronic EF lens mount that the BMCC m43’s “passive” (purely mechanical, not electronic) lens mount doesn’t offer.

If the BMCC m43 were an electronic mount, I might have decided to wait for it because I own a few electronic Lumix m43 lenses. But it isn’t. And I don’t own any manual native m43 lenses, and won’t soon be buying any. So for me, “A BMCC EF in the hand is worth two BMCC m43 in the bush”.

Next year I may consider buying a BMCC m43 as a 2nd cam for alternate angles and to make use of manual, non-electronic m43 lenses I may rent or buy, and as a backup camera, e.g.: relatively inexpensive “insurance” for when things inevitably go wrong.

Other people may have different reasons and situations, and thus make different decisions. That’s OK. It’s all good.

There’s not 1 perfect camera for every production.

Photo credit: John Brawley.

My list of related links, short films, and resources for Blackmagic Design cameras.

For my words only: ©2012 Peter J. DeCrescenzo. All rights reserved. www.peterdv.com

Note: I don’t receive income or renumeration for this blog, or for products seen or mentioned here. Advertisements on the page have nothing to do with me. The ads support WordPress, the publisher.

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