When imaging deep-sky objects with my long exposure modified cameras I often have to discard frames because the stars are not nicely round, but have become streaks.
This is caused by the imperfection of the gears of my LX200 mount: the Periodic Error.
The problem is that I can only assess the quality of an image AFTER the whole exposure time has elapsed and then I am too late, because the streaks are already there :-\

The now following part describes how to use K3CCDTools to image with one webcam and autoguide with another webcam.
And here I describe how I image with K3CCDTools and my ATK16IC camera and Autoguide with Guidedog and a modified webcam.

The solution for this is AUTOGUIDING, whereby TWO webcams are used and automatically guiding corrections are made 'on the fly' during the long exposure imaging by the imaging webcam.
So: one webcam does the actual long exposure IMAGING, while the second GUIDING webcam is aimed at a bright star with shorter exposure times [but it is very nice if this Guiding webcam is also modified for long exposure, so that you can use e.g. exposure times of 1 second which makes it MUCH easier to find a good guide star].
The Long Exposure of my webcams is triggered via the parallel port of my laptop computer, and as I have one one parallel port to service two webcams I needed a Splitter Box The computer software assesses the incoming image information from the guiding webcam and determines the shift in pixels and gives a message to the RA and DEC motors of the LX200 in terms of "a little faster/slower please".
This all happens while the long exposure imaging is going on.

Here are my own experiences with my LX200; whereby I image via my LX200 telescope and guide with a piggybacked 700mm refractor: my "Lidl" scope

One more thing: it is very nice that your Polar Alignment is as perfect as you can get it.
And lastly: make sure that your setup is properly balanced

LX200 with piggy-backed Lidl scope February 24, 2006.
LX200 with piggy-backed Lidl scope

1. Prerequisites
For Autoguiding I used the following:

2. Preparing for Autoguiding
Note: I assume you already know how to image without guiding; should you not know this then first go to my Tutorials page, e.g. Beginners or DSO Tutorial

Here are side-by-side the settings I use: I always use the instance 1 as Imaging Instance and instance 2 for Guiding.
I have marked my long exposure cables also 1 and 2, so that I do not mix up things.

Imaging Instance [1] Guiding Instance [2]
Note the difference in bit pattern (the green zeros and ones) !! Note the difference in bit pattern (the green zeros and ones) !!

As I have an LX200 10" F/10 Classic telescope I selected the LX200 interface, which works fine.

3. Setting up the Imaging instance

Note: this Tutorial assumes you use a modified webcam for imaging, because that is my situation.
But of course you can use any other imaging equipment, such as DSI, Digital Camera etc. or even a film based photo camera.
For all imaging equipment the same issue applies: "we want no streaky but pin-pointed stars".

4. Setting up the Guiding instance
5. Automatic PEC Training of an LX200 Classic with K3CCDTools

Did you know that you can use your Guiding instance for automatic PEC Training?
[Note: PEC training is only applicable for Polar mode mounted LX200's and not for Alt/Az; see your LX200 manual.]
It works like this:

6. Examples/results of my Autoguiding setup

Nice flat graphs !

54 autoguided exposures of 40 seconds:

This screen print nicely shows my autoguiding accuracy: round stars!
Imaging: William Optics Zenithstar 80 ED II APO, f/6.8 [focal length 545 mm]; exposure time: 300 seconds; camera ATK16IC.
Guiding: LX200 10-inch f/10 [focal length 2500mm]; camera SC3 modified webcam.

Autoguiding with GuideDog
I am always ready to try something new so I tried out to Autoguide my WO ZS 80 ED II APO and ATK16IC camera with my LX200 and Vesta SC3 camera with K3CCDTools as imaging software and GuideDog as Autoguiding software.

I used instance 1 of K3CCDTools as imaging instance [as usual], but instead of firing up the 2nd instance of K3CCDTools for autoguiding I now launched GuideDog instead.
That turned out rather well, but intially I of course had to learn how to operate GuideDog.

After a while I settled for the following settings [which might need fine tuining but nevertheless I record them here for your and my own reference]:

[For Relay Box and Logging I used the default settings].