Stupid technical spec of the day

A digital camcorder with a quoted 1000x digital zoom and 35x optical zoom.

Now, an optical zoom is a set of lenses that focus light like a telescope. 35x is kind of silly -- if you don't have a rock-solid tripod, the shake is going to render the image at full zoom pretty much unusable.

But. A digital zoom isn't really a zoom -- it's just blowing up the pixels that you've already got and discarding the ones around the edge. With a 2x digital zoom, you threw away 3/4 of the pixels (1/2 of the vertical, 1/2 of the horizontal). With a 35x digital zoom, you would be throwing away all but 1/1225 of the pixels. If this is a HiDef 1080P video camera, 1920x1080 original frame size, you've reduced your effective resolution to about 60,000 pixels. That's not so great. But that's not what they're quoting -- they're saying they have a 1000x digital zoom. That means they're throwing away all but 1 pixel in a million.

1920x1080 = 2073600

2 pixels left at 1000x zoom. Utterly useless.

Stupid technical spec of the day

A digital camcorder with a quoted 1000x digital zoom and 35x optical zoom.

Now, an optical zoom is a set of lenses that focus light like a telescope. 35x is kind of silly -- if you don't have a rock-solid tripod, the shake is going to render the image at full zoom pretty much unusable.

But. A digital zoom isn't really a zoom -- it's just blowing up the pixels that you've already got and discarding the ones around the edge. With a 2x digital zoom, you threw away 3/4 of the pixels (1/2 of the vertical, 1/2 of the horizontal). With a 35x digital zoom, you would be throwing away all but 1/1225 of the pixels. If this is a HiDef 1080P video camera, 1920x1080 original frame size, you've reduced your effective resolution to about 60,000 pixels. That's not so great. But that's not what they're quoting -- they're saying they have a 1000x digital zoom. That means they're throwing away all but 1 pixel in a million.

1920x1080 = 2073600

2 pixels left at 1000x zoom. Utterly useless.