Focusing problem in version 3.1.0.457

Hello .

I have a problem with focusing in the latest version of SGP 3.1.0.457.

AF focuses correctly after the third attempt.

I attach a video that shows this problem.

The film can be downloaded from the attached link.

greetings
https://drive.google.com/open?id=1-y_CPUQp6jXeDI29_hclQkRsz2pamp7v

Wojtek.

Hi Wojtek,

I was watching your video and I have the impression that the focuser moves inwards instead of outwards when starting the focusing routine. Did you check that the In and Out buttons on the focuser control moving the focuser in the right direction ( In button - inwards, out button -outwards ).
This could be the reason why the smart focus needs to recenter the graphics on the expected focus position. Normally this is not necessary. I suspect you need to reverse your focuser direction.

CS,
Janos

Hello Janos, thank you for your interest in my topic.
Today how the weather will be, I will check your suggestion.
greetings
Wojtek

I really like the idea of showing a video, it shows much more than a description of the problem alone would.

I assume the focus was not too bad to start with. What I saw was that when the filter changed after the goto and before the autofocus the focus moved in by just about 2000 steps. When the autofocus started the focus moved out to 33.2k and then back in to 32.8k. This makes sense w/ how the autofocus works and your setting of 500 for backlash. Focusing then failed twice as it started too far in and it wasn’t until the third try that it had moved out far enough to focus.

So, given that the focus moved in by 2k when changing to the SII filter the question is, do you have some per-filter focus settings? It sure looks like the SII filter is set to move in 2k steps relative to whatever filter you were on when doing the goto.

I agree with @DeepBlueSky, the first two AF runs were starting too much inwards. Before focusing, when you plate solved, the position was 34359.

Then as @DeepBlueSky said the first run is centered at 32319 (-2000 steps), then the second run at 32859 (-1500 steps), and then you get good focus at 33359 (-1000 steps). This is 1000 steps inward with respect to the first position before the change to the SII filter. So if your first filter was well focused, I guess your Lum (?), then it looks like the SII filter is about 1000 steps shifted inward.

Hello, and thank you all for your interest in my problem.
I am sorry that I am only replying now but recently I had to stay at work a little longer.
In previous SGP versions I did not notice this problem.
This problem began to appear when I installed the latest version of SGP.
Yes, I have the focus setting for each filter separately and I actually have the 500 steps loose setting.
The film also shows that AF begins to draw a curve in the opposite direction than normal.
I was looking in the AF settings but I can’t find an option where I can check if the AF draws a curve to the left or to the right.
Regards Wojtek.

Hi @Wojtek23
I watched the video as well and agree with both @mikaelA and @DeepBlueSky. It appears the start of the focus run is way too far out of focus and the first move moves puts the focus point at almost in focus. Given the case that you are ending up at the first focus point almost in focus it makes sense what you are seeing. It appears the filter offset may be way to much. To experiment I would suggest to start with a zero offset and see what happens but make sure you are in focus from the filter you’re using as your offset from. 2k offset seems extreme unless you have a very high resolution stepping system or your filters are from different manufactures.

Hope this helps,
Mark