TempComp control

Sequence Generator Accepted Unplanned
1

Any help is appreciated.

If TempComp (between frames) is enabled, does it adjust focuser position after every frame, or there is control, eg, every N frames, or every N degree of temperature change? I know controls exist for auto focus, since I dont plan to use auto focus, I would like to get similar controls for TempComp.

2

Yes, temperature compensation movements are made only between frames. We don’t have any current plans to add temp comp triggers (you shouldn’t need any… the only trigger is that temperature changes). In terms of when to do it, there is no higher frequency you can achieve except for after every frame (unless you move the focuser while integrating… we choose not to do this as some focus controller / motor combos are “rough” enough to introduce unwanted vibrations).

3

Ken,

Thanks for the reply.

It will be useful to have similar control (at least Hysteresis) as AutoFcous, because temperature may hover around and I dont want to move focuser back and forth because any movement may potentially cause issue.

Another question: if I use PHD2 for guiding, and during AutoFocus, is it possible to disable guiding and restart it after AutoFocus? The reason is that I am using OAG, and PHD may lose star when star is out of focus during AutoFocus.

Thanks

4

5

That’s reasonable. I will move this to accepted unplanned to calculate this for temperature output. No plans for alternate triggers though.

6

I’ve addressed this in focuser drivers by having a thread in the driver that reads the temperature from the hardware every second and generates a running mean over the last 2 minutes.

7

Thanks Ken.

8

Chris,

I have seen large temperature fluctuation in the past which I think can not be filter out by averaging the temperature.

BTW, it is an interesting idea of having “thread in the driver”, could you point me any website talking about it? I googled but not sure which one is the correct one to look at.