Letterbox Vs. Squeeze

This article is a little dated now. But there are still people shooting on DVX100’s or similar cameras, so I am putting it up.

I recently received the following comment about my “Stop the Letterboxing!” post, and it brings up an interesting point about some standard definition cameras with 4:3 imagers.

“Regarding “Stop the letterboxing!”…… Without the use of the awkward anamorphic adapter for Panasonic’s DVX100 series, letterboxing is the best way to get projects out for projection. The DVX actually has more resolution letterboxed than in SQUEEZE mode. Just ask Barry Green, author of “The DVX Book”. Or, better yet, ask James Longley whose “Iraq in Fragments” was nominated for an Oscar this year. It was….. eegads…… LETTERBOXED.”

I had a first generation DVX100, which does not have a squeeze mode, so I did some research and found out what was going on. The DVX100A/B has a 4:3 CCD imager and in order to shoot 16:9 it has to cut out the middle section of the image and throw away the rest of the pixels; in other words it letterboxes the 4:3 CCD. Other cameras such as the HVX200 have 16:9 CCD imagers and can therefore use all of the available pixels to create the 16:9 anamorphic image. This relates to the 2 ways to record this middle cut image in the DVX100A/B. The two options are Letterbox and Squeeze. Letterbox simply takes the middle cut of the 4:3 CCD and inserts it into a black matted 4:3 video image to create the 16:9 image. Squeeze takes this same middle cut of the 4:3 CCD and stretches it to cover the entire 4:3 video image. This is true anamorphic, but it is pointless because it is created from an already letterboxed 4:3 CCD. If the anamorphic image is created from a 16:9 CCD than you are benefiting from using many more pixels. This is also why the anamorphic lens adapter will result in better quality images, because the lens creates a squeezed image on the entire 4:3 CCD. There is some debate as to which mode gives better quality, but I would recommend going with the Letterbox mode. The Squeeze mode adds another layer of image processing that likely loses information and precision.

Its funny that “Iraq in Fragments” was brought up because I actually encoded that for digital release. He did what I would have recommended he do. He shot in Letterbox mode, but then mastered in HD, which is not letterboxed, and to my knowledge never made a letterboxed video master. The main point of the “Stop the letterboxing” post was that letterboxing often needlessly throws away pixels and degrades image quality, but in the case of the DVX100 series since shooting 16:9 is only possible by letterboxing the 4:3 CCD there is no getting around it. So if your cameras can only letterbox your video to get to 16:9 you will have to live with it, but you should never go back to letterboxed, move it to anamorphic or HD for your video masters or DVDs.

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