Off-Axis Guiding

For guiding I use the Starlight Xpress Lodestar camera. This camera, in cooperation with the PHD software, works extremely good. A guidescope is not longer necessary. I use a SBIG Off Axisguider.
Finding a guide star is easy with the TEC. With the Meade, with 2500 mm focal distance, it is sometimes more difficult, but untill now I always succeded in finding a guide star. PHD shows very, very faint stars, but guiding is no problem. PHD is freeware.
lodestar The Lodestar is a perfect guide camera, but the connections with laptop and mount look weak.
lodestar In the past I used a TS_OAG9 with the ST-8300M. The distance between the chip and the flattener should be 85 mm (or between 82 and 88 mm). I found this solution.

Guiding with ST-4

Before I bought the Lodestar I used an old SBIG ST4 CCD camera, combined with a Vixen 70S guidescope. Although the focal length of the guidescope is only 420 mm, with the ST4 it guides perfect. Even when you are making photographs with telescopes with a focal lengths of 1000 or 1500 mm, there is no guiding problem.
Working with the ST4 is more challenging. If you don't want to loose your guide star, put SA on 9, that is to say, put it off. The default value is 2. That is for a perfect sky and you probably don't have such a sky. In addition, the chip is very, very small. You absolutly need a cross hair eye piece to center a guide star.
The way I managed the ST4:
  • EA Exposure Adjust: <= 2 sec
  • B Boost: 1 - 3
  • bA Brightness Adjust: A (A=1x1 F=3x3 pixels)
  • SA Scintilliation Adjust: 9
  • FL Focal Lenghth: S (L when > 1250 mm)
  • C1,C2 Calibration: 20 (movement between 6 - 20)
  • H1,H2 Backlash: 0
  • AA Averaging Adjust: 0