Astrophotography with small telescopes
Tips on using the ST4 - Autoguider
Here are some tips and first start parameters to guide with the ST4 from SBIG
| First step
|| Do the first steps to get handy with the ST4 from your backyard under normal conditions. Don't use the best nights for these steps.
It doesn't matter if the moon is in first quarter.
Take a street lamp at least 5 kilometers away and center it in the middle of the field. Place a white paper at the focuser and find the focus.
Then stick the ST4 into the focuser, fix it with at least two screws and press FIND AND FOCUS. Move the focuser until the first value of the ST4 gets as high as possible.
Remove the ST4 and insert an ocular to see wether the image is focused or not. If it is focused everything is ok, if not take another ocular to see if you can get the focus. Don't try to the focus with the ocular because the star/lamb should be focused for the ST4.
Move the telescope to a moderate bright star, don't use the brightest ones. I would recommend a 5 or 6 magnitude star. Place the star in the middle of the image using the ocular just used. Replace the ocular with the ST4. Move the ST4 around until the mark with the serial number is parallel with the declination axis of your mount. Make a dark frame and then press FIND AND FOCUS. Move the focuser very slightly until the brightness value is at it's highest point. The brightness value should be stable. If not, the seeing is not very good.
Mark the focus to find it quickly later.
||Press FIND AND FOCUS and look for the brightness value. Change the exposure time (EA) to 2 seconds and the boost factor to get a brightness level between 20 and 50. Then press CALIBRATE to make a first calibration run. Now the ST4 moves the telescope around in each axis to measure the movement. If it says HELLO after the calibration everything is ready to start tracking. If not change the calibration times for the two axis (C1 and C2). If your mount has much declination backslash increase the C2 to 10 or 15 seconds.
Press TRACK to see how it works. Let's track it for at least 10 minutes to see how it works.
||See what the average failure is and improve the tracking by modifing the values of exposure time, averading adjust (AA), scintillation adjust til you get a good averaging failure.
||exposure time = 2 or 3 seconds, averaging adjust 2 or 3, scintillation adjust 5.