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Sunday, April 1, 2007

HD Digital Video


The world of high-definition video offers new opportunities for nature photographers


Some HD camcorders offer a high-megapixel image capture separate from the video capture. This can be effective. However, you also can capture still images directly from the HD video with good results. I’ve made captures from video from the XH-A1 that I blew up to very good 10x18-inch prints that would look great framed on the wall.

Before explaining how to get high-quality image capture from HD video, I have to qualify a few things about video to stills:

1
Video is normally shot at slow shutter speeds (1/30 to 1/60 sec.). This allows a blending of action from frame to frame so we see motion better. However, it causes a problem for capturing still images; cameras must be tripod-mounted and you must be careful of moving subjects.

2 Video doesn’t have the same color space as digital cameras. It’s a more restricted space, though it can give excellent results, just not the same as that from a digital camera. You’ll need to make some adjustments in Photoshop or another image-processing program.

3
Many cameras offer high shutter speeds that can stop action, but as you shorten the shutter speed, the video can look choppy or strobed. There’s a compromise that must be made, depending on the key use of the video, or else you need to shoot two segments at different speeds of the same thing.

Whether you’re shooting video or capturing still frames, you need to download your video to your hard drive. Video takes up a lot of hard drive space, a minimum of 1 GB for every four minutes of video. You need a fast, big hard drive to work with video.

Most of the latest video-editing programs will handle and capture HDV footage, and they will allow you to capture a single still frame. I’ve found Adobe Premiere Elements, Apple Final Cut Express and Pinnacle Studio to be affordable, easy-to-use programs for downloading, editing and outputting HD video.

Following is a simple way to capture a video still (check your software’s manual for the specific controls needed). I’ve used this to get image files that make great prints.

1
Using your video-editing software, find the spot in the video that you want to capture.

2
Move the scene back and forth, a frame at a time, to find the exact point that shows the sharpest, best image with the least artifacts from interlacing. This is important, and you may be surprised by the range of image quality that appears.

3
Export the shot as a still frame and save it to your hard drive.

4
Open the shot in Photoshop or another image-processing software. If shooting HDV, you’ll find the image isn’t full width and looks squashed left to right. Use Image > Image Size, check Resample, uncheck Constrain Proportions, then set the Pixel Width to 1920 and click OK.

5
If your program has a de-interlace control, try it, though don’t be surprised if it doesn’t have a big effect. To deal with interlacing and compression artifacts, try using the Blur tool just on them and be careful not to oversharpen them. You may have to sharpen to a layer and remove the sharpening done to interlacing artifacts.

6
Process to get the best image as you’d normally work a photo.

 


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