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In lugnet.space, David Laswell writes:
> [...] Basically, digital zoom doesn't do anything that you can't
> accomplish by enlarging the image with MS Paint.
I don't think that's quite correct. If your CCD or CMOS chip has greater
than 8 bits of depth on each spectral band (most do), then an on-camera
digital zoom should contain more information than a post-processed
zoom.
For example, suppose you have a 10-bit CCD (common), 10x digital zoom,
and 5x optical zoom. Now if you take a 24-bit color JPEG photo at 10x
(digital zoom), download it from the camera, load it into Photoshop, convert
it to a 16-bit image, and resize the image to 50% (half size), that _should_
contain more detail than if you had just taken the photo at 5x (optical zoom).
If they look identical, then the camera has a really poor digital zoom.
> [...] If you could shoot from across the room with at least 10x
> Optical Zoom, you could take a good low-angle shot of a diorama
> spanning a 2x2 grid of large baseplates without any part of it
> being out of focus.
That depends enitrely on what aperture you use and what final viewing
size you view the photo at. You could get away with a large aperture if
you're going to view the photo really small, but if you plan to view it
large and expect it all to be in focus, you'd better use f/16 or smaller!
> The other thing that can drastically improve photo quality is to always
> use a tripod (digital cameras have a really long shutter time,
Digital camera shutter times aren't any longer than film cameras. If you're
working with poor lighting, your camera will want to take longer exposures
whether it's digital or film.
Ya, using a tripod is pretty important if you're not using a flash[1]. If your
camera doesn't have a remote trigger, use the count-down timer -- you
don't want the camera jiggling when you release the shutter button.
--Todd
[1] And it can also be important even if you are using a flash, when you're
shooting with a large aperture (e.g., picking up ambient light) and you're
a relatively long distance from the subject (so shake matters), because
even though the flash may fire for only 1/10000 second, your camera's
maximum shutter sync speed is 1/200 second or at best 1/500 second --
enough to register blur on a large image if you pick up an ambient light.
On the other hand, if you're shooting with a pinhole aperture and flooding
the subject with your own strobes, then the ambient light will be insignificant
and you won't need to worry about shake blur.
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Message has 2 Replies:
 | | Re: taking good photos
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| (...) I think you are confusing color depth with image area resolution. If the CCD chip has an area of X-by-Y pixels and you are at maximum optical zoom, then any form of digital zoom requires interpolating between adjacent real pixels. The color (...) (22 years ago, 22-May-03, to lugnet.space, lugnet.publish.photography)
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Message is in Reply To:
| | Re: taking good photos
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| (...) No, digital zoom is a complete joke, and it's a really lame way to justify charging more for a camera. Optical zoom actually uses true camera optics to magnify the image before the camera records it. Digital zoom takes the image _after_ the (...) (22 years ago, 18-May-03, to lugnet.space)
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