Post by davy on Apr 17, 2017 14:03:11 GMT
my personal view on video astronomy
so what is video astronomy and how is it done
video astronomy is a cross over from visual astronomy and astrophotography
so why should I think about doing it ,when I can do the others mentioned above.
video astronomy over visual astronomy,, the human eye is replaced by a camera and will give you coloured live views of objects in space, where the mk1 eyeball would give you a faint grey object in the eyepiece, the views of the moon can be seen more clearly and steady.
there is also the advantage of seeing objects on large screens this is a great asset for disabled astronomers and outreach events.
video astronomy over astrophotography,,, the costs in astrophotography can be frightening and the time in post processing can be long as well.
equipment
so what do I need
if you have existing equipment it may be of use in video astronomy
depending on what you wish to video will have an impact on what is recommended
webcam.. cheapest form of video capture..it can be mounted to a telescope and can show views of the moon..
to get better views, you need to invest in a tracking telescope mount
the cheapest form of this is a small eq mount with a clock drive, this moves the telescope in r/a and stops star bloat and star trails caused by the rotation of the planet.
there are a few types of driven mounts and can do a good job but I recommend a eq mount over an alt az,,these come in go to versions as well
the better the mount the better the images.
but with short video capture alt/az mounts works well.
the cameras used have moved more towards usb and computers but there are a lot of video astronomers still using analogue camera set ups.
the analogue camera set up,,
this came from converting sensitive long exposure cctv cameras.
the most widely used is the Samsung scb2000,
so how do we use it,
the camera has a built in factory ir filter and it best removed as it cuts out the best spectrum of light for astronomy,check out utube on how this is done.
the camera requires a 1.25 to c nose piece to fit camera to the telescope
you then require a 12v dc power supply,,this can be a car battery jump pack,, note some 240ac to 12v dc adapters can give distortion to the captured images.
next up is a video feed ,this is done via a bnc connector to depending what you wish to connect your camera too.
a tv,,,then a bnc to rca connector cable is required.
a computer,,then a video grabber device is required,,this changes the analogue signal to a digital via the grabber,,, easycap is a very good video grabber.
now you are set up camera wise,it should be mounted to a telescope and during daylight hours pointed to the furthest away object and focussed,,, use the menu and change the sense up settings and take a note of what happens,,this will help when you come to try at night.