Astrophotography with small telescopes

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Indirect Guiding

The following description of "Indirect Guiding" depends on using an Micro Guide ocular. First you must measure the linear scala for your telescope used for the guiding.

S = Scale in arc seconds
f = Focal length
V= Movement of the comet per minute

S = 20626/f

VST = Movement per minute of one scale part
TST = Minutes per scale part

VST = (V*f) / 20626
TST = 20626 / (V*f)

Now you can make a table including the time when to reach an given scale part.

When you are at the telescope seek a guide star and set it in the middle of the ocular. Rotate the ocular until the marks of the ocular correspond to the North, South, East, West directions. Check it by moving the telescope. Set the star onto the calculated position angle, rotate the ocular until the starting point of the scale running from 0 to 60 lies just ahead of the starting point. Set the start onto the starting point. Start your image and make the calculated guiding steps.