Auto Focus Routine Help

Sequence Generator Auto Focus
1

Hey guys I have been using SGP for about a year and a half and I love it! I recently bought a new telescope and I’m trying to set up an autofocus routine. I had an autofocus routine with my SCT that worked ok I guess. I followed the guide in the manual and the suggested steps were nowhere close to what they needed to be. I experimented with a bunch of different steps and it eventually passed, but I feel it could be better. Ive never really got a good “V” curve. Mine always looks a little flat and the first step sometimes goes up to make a little wing. Im currently using a Explorer Scientific 127MM refractor with the OEM focuser. Im using the Pegasus focus cube V2 to do the focus.

When I Subtract the “in-focus” focuser position from the new (current) focuser position. Multiply this
number by 2, divide it by the number of “Auto Focus Data Points” minus 1 I came up with 45. When I ran the focus routine the V curce was completely flat. After changing the steps to 150 my curve looks like the images below. So I guess my question Is my V curve ok? Am I doing something wrong? Could this be any better than it currently is running?

Thanks in advance!

Chris

IMG-3114
IMG-31141467×1254 860 KB
IMG-3113
IMG-31132719×2032 2.69 MB

2

Hi Chris,

You are very close. I would suggest two changes:

  • The value for the backlash compensation is not big enough. In SGP, go to the setting for backlash and double the value you have there. That should take care of the wing on the right side of the curve.

  • Reduce the number of focusing points from 9 to 7. This will reduce the focusing time and will improve the working of the “Smart focus” option, should you ever need it.

Kind regards,
Horia

3

I think you can also reduce the step size, to avoid the dog ears, which can be a sign of moving too far away from focus,