CCD Procedures

CCD Imaging

A typical evening starts with powering up the gas generator.
The computers in the trailer are connected through back-up
power supplies. 

The observatory requires power for the ST-6 and ST-4, the
Kendrick de-dewers (for Zenith shots), the dome motors and
the closed circuit TV that links back to the trailer so I can 
see the computer screen from the observatory. ...decadent,
but very useful for rough focusing after focal length changes.

The LX-200 is synced to a bright star, and thereafter is always
aligned.  I have found that the most important thing about
polar alignment, is to make sure the scope is exactly parallel
to the fork arms. 

Back to the trailer to select an object with the 'Sky' program.
I make a short 5 second integration in focus mode, then a 
star in the field is picked off to aquire best focus.
I have found that there is too much back lash in the LX-200
focuser, even when using the JMI motofocus. 

The solution for remote focusing was to install the NGFS focuser 
that fits on the visual back of the scope before the color wheel
and ST-6. This eliminates backlash and saves considerable
time. (It used to take me about 45 minutes to achieve focus
using the LX-200 focuser).

I turn then to the Laptop and ST-4 and see if I have a guidestar
in view. If not I have to run out ...ugh!  to the observatory and
adjust the tangent arm on the 800 mm guidescope and make 
a visual capture. 

Back in the trailer I, make continuous 5 second or so integrations,
while I configure the ST-4 travel parameters for the RA and Dec
of the target I have selected. This is easily done with the 
CCDtrack software.

Focusing done, guide star aquired, I can now use the ST-4
and laptop to exactly center the object visually on the ST-6 
computer screen while the other computer is continually 
downloading  fast snapshots ie: The ST-4 does all the positioning
of the LX-200, the ST-6 just takes pictures

I make most all my integration multiples of 3 minutes. You cannot
easily exit Skypro if the laptop/ST-4 is showing any poor tracking, 
so I take multiple images and join them in CCDops or Hidden image 
afterwards. Contrast seems to improve this way as well.

For black and white, I will usually do about 5 x 3 minute 
integrations for a total of 15 minutes. You can get a good
image in just 30 seconds but you need a 'deep with data' image
to do processing afterwards.

For colour, As attested by Jack Newton, the ST-6 needs RGB
integrations of 1-3-5 My usual aim is to get 2 shots x 3 or 6 minutes 
of Red. 18 minutes of Green, and 30 minutes of Blue. This in
total is still just a 6 minute image. A 9 minute image would
require 27 minutes of Green, and 45 minutes of blue.

When shooting colour you may get 1 object a night in the summer,
and  2 in the winter.  Thay's not so bad, when you consider it's
taken David Malin 20 years to get 200 good pictures!

Visual CCD Imaging

CCD imaging for 'Keeper shots' can take a lot of time, and
not unlike film photography, you can get a lot of shots that 
are less than perfect, due to sky and equipment conditions.

I have poor eyesite (trifocal glasses), and it gives me a lot of
pleasure, just to bomb around the sky, locating objects with 
the 'Sky' program, downloading a 30 second or 1 minute shot, 
and I can SEE the objects better than with the telescope visually!
...and faster too.

On the maiden voyage of the ST-6, from Toronto with all it's
sky glow, I downloaded some 50 galaxies in one night, and 
SAW them better than I had ever, even through the largest Dobsonians.