Used the software for the first time Friday and was not able to achieve autofocus. Ran it around 30 times and it only finished (100% ) 3 times. those 3 all said the HFR was too high. The rest of the time it restarted. Not getting a V, more like a W. Not sure what to do to fix this.
Mount AP1600 , Camera Canon 5Dsr, Focuser Optec FocusLynx.
What are your auto focus settings and what scope?
The scope is a TEC250 ( 10 inch f/8.8). Not sure what you mean by settings. The iso was 800.
We moved to various locations and got anywhere from 8 to 40 stars to autofocus on. Tried 1x1 4x4 and 2x2 binning on the camera. Hope to get clear skies to try again tonight. Any suggestions on what my settings should be?
What do you have for these settings (specifically Data Points and Step Size):
We tried 9 data points and also 7 data points. Step size 100, 10, 50
I would suggest that you enable the option to “Save Auto Focus packages to:” and make several autofocus runs, zip up the packages and post them here so we can take a look at them.
I’m not sure what else to try. Perhaps there’s some backlash in the focuser? Are you starting the autofocus run where the image is already close to focus?
If you start close to focus, when the focuser racks out and the first image is taken, what is the resulting HFR calculation? You want the outside points of the V curve to be about 3-4x the HFR of the in-focus image. So if your in-focus HFR is 1.0, you want the outside data point to be about 4.0. Make sure your focuser is moving far enough.
We start with image in focus using a Bahtinov mask. The readings we get for HFR are between 5.6 and 8 depending on target. We never get above about 9 or 10 when it racks out.
Based on those numbers, I don’t think your step size is large enough. If
your initial HFR is 6, then the first autofocus data point should be at
least 18. Try pushing the step size to 250 and see what happens.
Another thing to look as is the exposure time. If it is too short, the stars are not detected reliably. Something in the region of 5-10 seconds is a useful starting point.
Have a look at this similar thread: