Now I have a couple more topics related to focusing. One is (probably) a bug and the other a feature request.

Bug: the documentation says "The Capture Image button will take a frame based on the current settings in the Camera & Filter Wheel Group."

Unfortunately it doesn't. I have been trying to find a good exposure for my narrow-band filters. They're only 3nm and need a much longer exposure than Lum. But whatever I choose, filter as well as exposure, gets replaced by Lum and 2 seconds (which are the values I've been using for autofocus) when I press the Capture Image button.

Feature request: the Build Offsets tool is very helpful, and I know that the advice for using it is that the system should be in thermal equilibrium. But even if the system is in equilibrium with its surroundings, the ambient temperature does drop during a night and over an extended run, it can drop quite a lot. In my case I've found that the narrow band filters need exposures of 15-20 seconds per frame, and if I want to use multiple frames (see later) it adds up to quite extended sessions. If I take 5 (or 3 as I've been doing) of each, then by the time we're finishing the narrow band filters a lot of time has passed since the reference Lum filter.

So my request is a checkbox to select going "down" the filters before going "across" the members of the set. In this way, if temperature is changing, it will be better reflected in the average positions.

A sub-request: the filter setting tool allows to set filter-specific exposure times. Could you add filter-specific number of frames? Again my narrow band filters have poorer V-curves than the broad-band ones and this might be a help for them

Hi Richard,

On point 1 it behaves like that because you have the filter locked to Lum. If you unlock it in Filter Settings do what you need to then reset the lock before you run Autofocus then it should work as you want. The manual could be clearer - I'll update it. I don't know why it was done like this. I could change it but usually when I change things like this it turns out there's a use case I hadn't thought of.

On point 2 whether you do rows or columns comparing data at different temperatures isn't going to give a great result. This is why I built Adaptive Focus into Build Filter Offsets.


You'll need to setup your system for Adaptive Focusing. I've just rewritten Adaptive Focus and need to update the docs but the user interface and ideas haven't changed...
docs.kde.org/trunk5/en/kstars/kstars/eko....html#focus-adaptive

When you have your system calibrated, when you run Build Filter Offsets each Autofocus run gets adjusted for environmental changes (temperature and if you set it up altitude). In this way the Autofocus runs for the same filter can be better compared and the offsets per filter should be more accurate. You can flip between "raw" and Adaptive Focus and compare the results.