TECHNICAL EDGE

Cinematography
In The Digital Age

by Greg Narkunas

Film is not dead, but it's also not alone.

With the introduction of the High Definition 24P video format and a complete range of "film" style lenses and accessories, motion picture film is not the sole acquisition medium for high-end production. Since the beginning of television itself, and continuing through advances such as the Ikegami EC 35 and the first broadcast CCD cameras, industry "experts" predicted again and again the demise of film. This was, and continues to be premature. Film still has every advantage it ever had and these advantages should not be ignored in some mad dash to blindly pursue "what's new" in technology. But with an ever increasing number of motion pictures, including the latest installment of the "Star Wars" saga, now being shot on high definition one thing is apparent, times and technology are changing.

What is 24 P HD and what separates it from regular HD?

There are a couple of fundamental differences in how 24P works when compared to other video formats.

First, it is progressive scans of the subject sort of the way computer screens display images. NTSC Video and earlier high definition format utilize an interlaced display of picture information. With interlaced displays each frame is broken up into two fields with a slight variation between the A field and B field. The second difference is that 24P is a series of 24 pictures every second. It is no coincidence that the frame rate is the same as with motion picture film. With conventional NTSC and earlier high definition formats the frame rate is roughly 30 frames per second.

What makes 24P better? A logical question arises in comparing 24P to conventional 30 frame high definition.

If 24P is 24 pictures per second and standard high definition is 30 pictures (60 fields) per second, what is the advantage to 24P?

Acquisition and Distribution Formats

24P is a high definition video format which offers the greatest flexibility in terms of distribution options. Let's look at why.

NTSC video runs at roughly 30 frame per second. More accurately it runs at 29.97fps, recording more frames per second than film, which runs at 24fps.

In the case of Film to tape transfers 24 frames must be expanded into 30 frames. The way this is achieved is referred to as a 3:2 pull down. The 3:2 pull down basically adds a field of video to every other frame of film. Without this odd field 24 frames of film would equal only 48 fields (24 frames) of video and we would be short of our necessary 60 fields (30 frames) we need to keep everything in sync.

To maintain an equal running time in a tape to film transfer, the information recorded at 29.97 frames in NTSC video must be condensed into the space of 24 frames. Merging the video fields together however, often results in visible motion artifacts.

24P offers a real advantage over other video formats for filmmakers planning to transfer their video-originated work to film. Running at the film frame rate means there is no conversion required when scanning to film. If one wishes to go to video, the conversion is a simple 3:2 pull down described earlier. An interesting byproduct of this 24P tape to NTSC tape conversion is the subtle "film look" effect which it produces.

Moreover, 24P aids in the video to film transfer by treating each frame of video as an individual picture and not multiple interlaced fields of video. The slightest difference in the fields of interlaced video will often result in artifacts when fields are combined into complete frames during transfer. These artifacts most often appear as jagged or distorted edges around moving subjects or areas in the frame when panning.

24P, on the other hand is immune to this problem due to it's a one to one ratio of video to film frames.

The Sony CineAlta, Digital Cinematography Comes of Age

As mentioned earlier, what distinguishes the HDW-F900 from Sony Œs earlier HDW700 HD camcorder is its ability to record at 24 progressive frames per second in addition to the 25p, 30p, and at 50 and 60 Hz interlaced modes. This versatility makes the 900 the camera of choice for nearly any HD application. Especially when it is uncertain what the final distribution medium will be.

The HD W-F900 accepts a complete range of motion picture accessories including matte boxes from 4x4 to 6.6x6.6 size both studio and clip-on types: follow focus devices in either studio or handheld configurations and zoom controls such as the Preston Cinema Systems Microforce Zoom Control.

Boston Camera Rental Company has had great success equipping these cameras with exotic, film style, lenses such as swing and tilts, telephotos, probe lenses and mesmerizer. Perhaps the most exciting thing to local cinematographers is Boston Camera's purchase of the the new Fujinon HD Prime Lenses, the first of only three sets now in the United States. These lenses are not a redesign or a conversion of some existing lens, but rather a completely new system Fujinon has taken great care in engineering to meet the demands cinematographers expect from only the best film prime lenses.

We have reached a point in the maturation of digital technology where the cinematographer does not have to compromise when faced with "going digital". Nearly any tool available in film may be used with the new digital cameras.

The economics of production, both film and tape, are always changing and High Definition acquisition is not always less expensive than film origination. What may be feasible on one show may be a budget buster on another but the viability of this digital option is sure to be a welcome development to cinematographer and producer alike.

Greg Narkunas has been the Vice president, Technical for Boston Camera Rental Company since 1997. He is a member of the International Camera Guild I.A.T.S.E. Local 600 and a member of The Society of Motion Picture and Television Engineers (SMPTE) Prior to Boston Camera he served as rental manager of the Camera Department, Boston Film Factory. Greg has worked in the equipment rental industry for 10 years.