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Camera 101: 16:9 Quick TipDoes your camera do it?
Why do we like the 16:9 format? The wider screen gives us a more cinematic feel, and as one reader pointed out, is similar to the way our eyes see wide horizontal field of view compared to the vertical. But does your camera do it, and do it right?
Because the 16:9 aspect ratio is close to that of projected movies, independent filmmakers wish to emulate the look in their work. For the low budget director shooting on video is the only way to go. Cameras like the Canon XL1s, Sony PD-150, and the Panasonic DVX100A have been popular for this type of work. Not surprisingly all of these cameras feature a 16:9 function. So is your camera recording true 16:9 or a cheap knockoff?
Without a true 16:9 chip (found in higher end cameras and according to specs the new Canon XL2), the camera can only capture the image using a standard 4:3 chip. This means one of two things; the camera is either anamorphically squeezing the image or letterboxing the shot when you turn on the widescreen (16:9) feature.
Anamorphic v. Letterbox
Because there are only 480 lines of information being recorded, you want to use as many of these lines as possible to achieve maximum picture quality. When you use anamorphic capture, the image is squeezed horizontally (stretched vertically) to capture the entire field of view. The result is your video looks thin and distorted when viewed on a 4:3 monitor, but you are using the full image size of the chip.
If your camera is letterboxing the shot, it crops the scene at the top and bottom of the view. Instead of using 480 lines, the camera is only capturing 360 lines, meaning you are losing 25% of your cameras resolution. This type of video can be displayed on a 4:3 monitor in the letterbox format. While it looks like true 16:9, one forth of the data is lost forever.
Obviously this is not good, but unfortunately is the way the widescreen mode of many prosumer level DV cameras work (especially the Sony PD-150/170 and VX2000/2100). Adam Wilt (www.adamwilt.com) has reported that other cameras, like the Canon XL1s, do some resampling for more vertical resolution, but this is still a fake 16:9 and not good.
So how do you know which way your camera is recording the image?
Do this simple test. Capture some footage using the normal mode. Pay close attention to the information at the top and bottom of the frame.
|This image was captured using the Sony PD-150 in normal mode.|
Now turn on the 16:9 feature of your camera. If, in the viewfinder, the top and bottom of your original image is cropped, then you are using the fake letterbox approach.
|Notice how the top and bottom portion of the image has been cropped, even though the focal length has remained constant.|
Instead of relying on pseudo 16:9 or letterboxing both resulting in a loss resolution, there are some other options you might consider. The first is to shoot normal 4:3 and letterbox in post. With this method you preserve the resolution of the image. The second is to use an anamorphic lens. The anamorphic lens squeezes the video and fits the entire field of view onto the 4:3 image area. While you may lose some of your zoom range depending on the lens you buy, the resolution will be preserved and you will get a true 16:9. I use the Century Optics anamorphic adapter for my PD-150 and it produces stunning images.
|Using the Century Optics 16:9 Widescreen Adapter|
For the aspiring filmmaker, understanding how your camera deals with 16:9 can have a huge impact in the way you approach your next project. If you plan on presenting your next feature in the theatre, you will want to preserve the shot by using as much of the image area as possible. The anamorphic adapter will help you there. If the adapter is not something you wish to deal with, consider getting a camera with a true 16:9 chip.
(If you wish to learn how Final Cut Pro deals with anamorphic footage, be sure to check out Final Cut Pro Quick Tip #43 .)
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