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When making a movie you must pick a format to work with. In this section we will examine the different DV (digital video) formats and aspect ratios, as well as how DV rates next to film. The chart below summarizes the DV formats available today.

The chart is organized with the highest quality formats at the top and works down to the lowest quality at the bottom. Formats grouped together in a tier are close in perceived image quality.

The bottom tier is considered consumer/"prosumer" by manufacturers. Yet even these formats are broadcast quality with a 5:1 compression ratio.

The top four tiers are high definition (HD) and the remaining tiers are standard definition (SD). When analyzing the chart, HD and SD formats should be looked at separately because they are very different.

The chart may seem overwhelming at first, but the key to ranking formats is horizontal resolution followed by the compression ratio. Notice how quality increases as compression decreases.

After compression, the next ranking factor is tape speed. Faster tape speeds maximize the data rate and minimize image degradation due to tape imperfections (i.e., dropout). For example, D-5 travels nine times faster than Mini DV.

In recent years, the price of HD cameras has fallen below $2,000. These prosumer models are the new choice of micro budget filmmakers. Professional cameras may have higher quality lens and CCDs, but the difference in image quality is not easily perceptible by the average viewer.

This point was beautifully made during a recent election when an MSNBC news segment cut back and forth between a consumer and professional camera (at the same location) with no significant difference in the broadcast picture quality.

It is safe to say that the future standard for all cameras--consumer and professional--will be HD. Resolutions below 720 lines will become a thing of the past. See High Definition Video for more.

Film vs. Digital Video

There are three visual attributes that make DV look different than film: exposure latitude, motion blur, and resolution. If you can control these variables, they will be less obvious to the eye and your DV will come closer to the elusive "film look":

Exposure Latitude  - A key difference between DV and film is exposure latitude, which affects contrast and detail. Color negative has a usable exposure range of 7 stops, with normal exposure approximately in the middle. Most stocks provide 4 stops overexposure and 3 stops underexposure where detail is still visible.

Video has a usable exposure latitude of 5 stops, providing 2 stops overexposure and 3 stops underexposure where detail is still visible. Exposure beyond the -/+ limits results in tonal compression and is reproduced as either pure white or pure black, respectively. Obviously, there is a loss of detail as well.

Since highlights tend to be more troublesome than shadow areas, exposure is generally geared to highlights, letting shadows fall where they may. This avoids the "burn-out" often associated with poorly shot video. Still, it's important to stay within video's usable exposure and contrast range.

Motion Blur - Film yields a slight blur in moving objects. This is known as motion blur and it results in a distinct fluidity of movement-- a prime contributor to the "film look." Motion blur is caused by film's relatively low frame rate of 24 frames per second. A telltale sign of video is its extreme sharpness and lack of motion blur.

NTSC video runs at 30 fps so how can such a small difference account for the radical increase in sharpness? The reason is that there are two interlaced fields for every frame of video, so the effective rate is actually 60 images per second (= 30 fps x 2 fields). This virtually eliminates motion blur, creating an image that is a bit too sharp and devoid of fluidity (the dreaded "video look").

The answer to this is a technical breakthrough called progressive scanning, where each frame is scanned once. In other words, the frame is scanned as a single field, with no interlacing. The lower image rate reproduces motion blur comparable to film.

These cameras generally use frame rates of 24fps to 30fps. 24 frames progressive, called  24p, simplifies combining video and film footage because there is a one-to-one frame relationship. The PAL version, 25p, matches the European film speed of 25fps. Many state of the art cameras have switchable frame rates and resolutions.

Another benefit of progressive scanning is a dramatic increase in resolution. This occurs because progressive scanning eliminates interlace artifacts (combed edges in movement) and interline flicker (noise in fine patterns). There is a study by William E. Glenn showing that perceived resolution in progressive scanning is 50% greater than interlace scanning (Understanding Camera Resolution, Broadcast Engineering, August 1999.

Resolution - The final difference between video and film is resolution. Many filmmakers erroneously assume that film is far superior across the board. The truth is, HD has all but closed the gap. See HD vs. 35mm Film for more.

Despite this, film is still far superior to standard definition (SD) video-- most of the formats in the above chart. To minimize this disparity you must make sure that nothing degrades the image quality when shooting. For example, improper exposure will diminish the apparent resolution of video by compressing tones and destroying detail.

Arguably, the disparity in resolution has less of an impact on the look of DV than exposure latitude and motion blur. It is not noticeable to the average audience, except of when aliasing rears its ugly head.  Aliasing can be minimized by avoiding fine patterns, particularly checkered and striped clothing.

DV has an interesting advantage over film that may, in part, make up for its lower resolution. It can "see" in low light almost like the human eye and captures beautiful images during sunrise and sunset. In fact, gain can be boosted to +12 dB with minimal consequence. This is true for Mini DV as well.

Transfer to 35mm Film

The ability to shoot on DV and release theatrically on 35mm film has taken great strides, with some interesting developments along the way. The trend started with The Celebration in 1998 and it is picking up momentum. Nearly 50% of all IFP submissions in 2000 originated on DV with hopes of theatrical release.

A combination of high quality DV cameras (Mini DV included) and progressive labs like Swiss Effects have produced truly stunning prints. Such transfers are made with a laser recorder. This state-of-the-art machine uses three laser beams to record RGB video directly to each frame of color negative.

If you anticipate transferring DV to 35mm, there are certain decisions and settings that you must make in terms of the camera, namely:

• decided on 4:3 or 16:9 aspect ratio (discussed below)

• switch on the dynamic contrast control

• switch off the digital zoom

• switch off the electronic picture stabilizer

• lower the detail level (or sharpness)

Some labs have preferred settings for different cameras. You should consult with the lab before shooting begins and run a test to see that your expectations are met.

4:3 vs. 16:9 Aspect Ratio

A cameras aspect ratio is a function of the CCDs shape. There are two video aspect ratios in use today. The standard ratio is 4:3, which provides the square broadcast TV image. The widescreen ratio is 16:9 and conforms to theatrical film and HDTV standards. Most professional cameras allow one button switching between ratios.

Some mid-range cameras have a 16:9 mode but do not have a true 16:9 CCD. Rather, they use a 4:3 CCD and simulate the wide-screen aspect ratio by masking the top and bottom of the image. This creates a widescreen effect, but uses less vertical lines in the process.

4:3 Chip in 16:9 Mode
 (shaded area appears black)

A true 16:9 chip uses all vertical scan lines, so resolution is superior. It has side panels that are used in the 4:3 mode and ignored in the 16:9 mode.

16:9 Chip
(uses all vertical scan lines, none masked)

You can tell whether the camera has a true 16:9 CCD by observing the image while switching to the 16:9 mode. If the horizontal view expands, the chip is 16:9. If the vertical view crops, the chip is 4:3 masked to simulate 16:9. In some cameras the both the vertical and horizontal changes. If this happens, the acid test is whether the horizontal view really broadens. If so, the chip is 16:9.

Whether you use 4:3 or 16:9 mode the resolution inside the visible frame is the same (you simply mask the top and bottom scan lines in the 16:9 mode). Consequently the choice is really a matter of aesthetics rather than quality.

When transferring to 35mm it is desirable to use all vertical scan lines (rather than mask some) to maximize resolution. That's why a true 16:9 chip is important.  In the absence of a 16:9 camera, some filmmakers use an anamorphic lens to squeeze all the vertical scan lines into to the 16:9 aspect ratio. You should consult the lab when attempting this.

If a 16:9 camera or anamorphic lens are not available, take comfort in the fact that the 4:3 chip yields surprisingly good results in both 4:3 and 16:9 modes when transferred to 35mm. Whatever approach you take, it is important to do a test transfer beforehand. The test should include short clips under various lighting conditions and ratios. Also, shoot different close-knit patterns to see how your camera handles aliasing.

Tips and advice courtesy FilmSchoolOnline.com

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