I created a 1440x1080 16-bit image with a transparent background in Photoshop. I worked out the height of a 2.35:1 aspect ratio frame by dividing the width of the HD-standard frame size (1920) by 2.35, which is 817 pixels. The area to be matted off is the difference between the full frame height and the 2.35:1 frame height, IE., 1080 - 817, which is 263 pixels. We need a matte at the top and the bottom of the frame, so each matte will be (263/2) 131.5 pixels high and 1440 pixels wide.

I set the rulers in Photoshop to show pixels, and drew a rectangular marquee from the top left corner, down to 131 pixels, and across the entire width of the image. I filled it with black and copied it, placing the copy at the bottom of the image to create the bottom matte. I saved the image as a PNG file, and imported it into Premier Pro CS3.

After editing the footage, I dragged the Matte PNG file onto the timeline in the top-most video track and dragged the length out to match the duration of the footage. I clicked File -> Export -> Adobe Media Encoder (AME) and selected the "HDTV 1080p 29.97 High Quality" preset. I changed the Field Order to "None (Progressive)" as the footage was shot in Canon's 30F progressive mode, and on the Output tab, made sure "De-interlace" was not selected. After AME finished rendering, I uploaded the footage to ExposureRoom. I did not select any of the ExposureRoom cropping options for this video so that the letterboxing is visible.

Lowsize: 6.48MBwxh: 336x189 Mdsize: 11.84MBwxh: 640x360 HDsize: 20.73MBwxh: 1280x720