Focusing of Camera model 3

[pw310]

I have a camera, which is in a weatherproof enclosure and the camera is protected by Entaniya Waterproof Case for Raspberry Pi Camera Modules. I have put it in Focus mode waited hours for it to focus, but it never achieves focus. I have tried to chage the lens position:

--autofocus-mode manual --lens-position 0.0
--autofocus-mode manual --lens-position 0.1
--autofocus-mode manual --lens-position 0.2
--autofocus-mode manual --lens-position 10
--autofocus-mode manual --lens-position 20
--autofocus-mode manual --lens-position 30
--autofocus-mode manual --lens-position 300
--autofocus-mode manual --lens-position -300
--autofocus-mode manual --lens-position -10
--autofocus-mode manual --lens-position -20
--autofocus-mode manual --lens-position -0.5

there is no change in the size of the star I am capturing, the attach pic is of Vega, on high magnification

UPDATE: During daylight I have spent a few hours taking frames with different lens positions, using clouds to determine an ideal lens position of approx 6.

Once dark, I have restarted indi-allsky with a lens position of 6 and the shape of Vega remains the same, which leads me to believe that this lens cover, although ideally suited to this IMC708 camera, should be limited to use in fish tanks, or outdoor weatherproofed coverage and is not optically suited for astronomy. If that is the case, if you have any recommendations for camera dome suppliers that are optically sufficient for Astrophotography wide field applications, I would be interested to hear them.

[aaronwmorris]

Just to verify. There are separate day time and night time libcamera options. Are you sure the focus settings have been applied to both?

[pw310]

Hi, yes, I change them both each time
With the help of ChatGPT I wrote a script to take frames at various focus points, which shows clearly there is a change ...

focus_timelapse_0p0001s_20250622_184433.mp4

[pw310]

The unwanted ring rround the stars seems to be generated by libcamera
I couldn't figure out how to remove it, I tried -denoise off -sharpness 0.0
but it made no difference.

So I switched to rpicam and that appears to have fixed it