"Chris.B" wrote:
On Tuesday, 21 July 2015 03:25:25 UTC+2, RichA wrote:
On Monday, 20 July 2015 10:47:36 UTC-4, Chris L Peterson wrote:
On Sun, 19 Jul 2015 23:19:43 -0700 (PDT), RichA
wrote:

The images are mostly horrible, compared with still camera, even with
expensive video cameras. Most astronomical subjects are static, don't
change in any time-frame where 1/5-1/30th second would make sense.
But they do sell cameras for this.

Video cameras are the ideal choice for planetary imaging, because of
the ability to use "lucky imaging", essentially a form of
post-processed adaptive optics. Images are selected for good seeing
and stacked for high dynamic range. This approach creates the highest
possible resolution images.

Yes, I should have been more clear. I was referring to video of deepsky
objects as opposed to still images.

Astronomical video cameras usually allow exposures up to 30 seconds,
while still outputting a conventional video stream. This allows the
camera to be connected to a simple monitor, with no need for an
intermediate computer. I've found this useful for public observing. At
our school observatory, we have a binocular telescope. With an
astronomical video camera on the 12" OTA, and an eyepiece on the 16"
OTA, we are able to put up a live screen image for a group, which
keeps people engaged while waiting for the eyepiece. Also, because the
video image shows more than they eye can see, it gives people a better
sense of what they're going to see at the eyepiece, which helps them
see more when they're looking.

Outreach seems to be their forte.

Even a compact digital camera focusing screen can become a video monitor
as we pause to frame, focus and then "snap" objects seen through the
telescope. The single frames captured become stills from the video seen
via the focussing screen. The same video can be passed via a cable from
the camera to a common TV screen to act as our video monitor. This is the
method I used to capture Solar transits of Venus and Mercury. Even taking
some quite satisfying "snaps" of the moon thanks to a massive and very
forgiving equatorial mounting avoiding shaking. Compact digital cameras'
lack of a simple remote shutter release is quite unforgivable IMO. The
method does rather lack the "magical" images possible from using stacking
with skill but is still satisfying in obtaining a record of a rare event.

You can use the timer instead of cable release. Many compact cameras now
have bluetoth remote capability.A selfie stick can be used as a remote and
is very cheap