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 acquire 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 Lap top and ST-4 and see if I have a guide star in view. If not I have to run out ...ugh! to the observatory and adjust the tangent arm on the 800 mm guide scope 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 acquired, I can now use the ST-4 and lap top 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 lap top/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 (in red) 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. That's not so bad, when you consider it's taken David Malin 20 years to get 200 good pictures!
CCD imaging 'Keeper shots' for Publication 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 eye site (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 of it's sky glow, We downloaded some 50 galaxies in one night, and were able to 'SEE' them better than ever before, even through the largest Dobsonians.
The LX-200 Scope is outside on the patio. The main ingredients for the remote setup are the electronics of the LX-200, Software like the SKY and Skypro and a remote focuser like Jim's Mobile NGFS.
The CCDtrack program for the ST-4 from SBIG, allows you to monitor the quality of the tracking from indoors.
The Meade LX-200 drive mechanism is perfectly suited for piggyback photography and many amateurs are getting good results with the Maxfield F3.3 reducer, but I like to work with the larger image size that F10 or at least F6.3 would provide, plus I like to do colour.
As a result I spent more time working on the LX-200 drive, than taking images... I have come to the conclusion that it was necessary to purchase a very expensive mount, or get the AO-7 tilt flip mirror device, in an effort to improve the tracking. In Canada a $6,000 mount would cost $10,000! ...so I got the AO-7 and am testing it out now.
When using the AO-7, it uses up a lot of back focus, It appeared that either the colour filter wheel or NGFS-1 focuser would have to be taken out of the light path. The use of a F6.3 reducer seemed to be out of the question as well, according to the traffic on the SBIG users site.
The best information about the AO-7 was on Doc Greiner's Web site.
After fiddling around endlessly, I finally came up with a configuration that required no machining or extra parts over and above that which came with the devices. Click on the photograph showing my setup.
Trying to focus with the Meade focus knob, even
with the JMI moto focus attached was all but impossible, due to the
severe backlash. You could waste hours getting it, 'spot on'. The
solution was to put the NGFS in the optical path.
The NGFS power cord plugs into the LX200 focuser port, no extra wires are required.
In this regard, it attaches exactly like the JMI moto focus., But this
is only half the solution....
If you are trying to function the NGFS from within ANY computer program,
the action is sluggish, and you cannot tell, (when you are operating remote) if you are moving the focus
motor or not.
I found that the E,W,N,S, buttons were unreliable as well, when
operating from the computer, both in DOS and Windows programs. I just
couldn't get a positive response with the computer screen buttons.
The answer for me, was to make a great long extension cord for my
LX-200 Key pad. In my case, it is 135 feet of regular 4 cond telephone
wire (just the thin 22 or 24 gauge stuff will do).
Now, from the trailer, I push the LX-200 control key pad buttons to focus,
and precisely move the scope. The action is positive. I can confirm
this by leaving the Key pad reading out RA and Dec numbers.
With this readout, (it stays like this most all nite), I know exactly
where the objects are, and if something has moved, and in the case of
the ST7, where the guiding chip is, in RA and Dec. I still use Sky 2,
but just as a chart and a goto.
Because the focus action from the Meade keypad is positive, I can
now focus in a few minutes.
One other thing you might do... is make a voltage divider out of 2
resistors, (1/4 watt) to drop the voltage from the focuser port of the LX200, which
is 18 volts, to 9 volts, which the NGFS was designed for. This keeps
you from speeding past the best focus position.
This is the schematic for the Plug/Resistors/socket, adapter cord, that is put inline to the existing NGFS cord.
The basement is looking more like the
JPL Lab
than a recreation room!
More Recent
Camera Configuration
In the Fall of 1997 I purchased a ST-7. The larger image size of the ST-7 is more conducive to web pages, printed copies and submissions to publishers. I found however that tracking became much more difficult with the 9 micron pixels as compared with the 25 micron pixels of the ST-6, which seemed much more forgiving.
Focusing by Remote Control
