in the next time I want to go for a apochromatic refractor for astrophotography. Apart from the optic itself, one big topic is the focuser and I hope to get some advice here.
For sure I want to have an ASCOM compatible motorized focuser with absolute positioning, so I can focus with help of SGPRO. Another feature I would like to have would be a sort of temperature compensation DURING imaging, because I think if doing narrow band imaging with 30 to 60 min integration time this might be very usefull.
For example: I found a thread in another forum where a Takahashi FSQ106 owner said that his telescope needs to be refocussed at least every 0.2 degree, if he wants to have really perfect focussed images. Although I think I will not purchase a Takahashi, I believe also other (cheaper ones) apochromatic refractors suffer more or less from the same problem.
If doing narrow band imaging with very long single exposures, my plan was to use such a temperature compensation during imaging AND to refocus between each image (just to be sure because the model used for compesation might not be 100% correct and allways suffers from the fact that there is always a lag between the measured temperature of the probe and the temperature of the optical relevant parts of the scope).
As far I have seen to do a temperature comensation DURING imaging is not possible with SGPRO. Therefore initial I wanted to post a corresponding feature request. But this request already exists and was to my regret rejected by the developers, because
(from: TempComp control)
Therefore my questions:
Please can anybody - who has expierence with focuser/motor sets, where the advertising is compromising “temparture compensating during compensation” - tell me, which system will actual work, resp. which will not work well (as they are too rough and destroying the image by its vibrations). I am currently thinking of the USB_Focus V3 system (prefered as a little bit cheaper) and the Focus Boss II Kit for FeatherTouch focusers. (I know that is not directly SGPRO related, but would be happy if I get an advice anyway).
If I use one of the systems above: Do you thing it will be possible to use them together with SGPRO? What will the USB_Focus or Focus Boss software do, if the SGPRO focusing routine starts? Will it be necessary to manually close this 3rd party software before and to restart after SGPro focusing?
Thanks a lot for your advice and best regards