Now the wedding season is over I would test this myself...but we've had nothing but cloud cover for two weeks here in the UK.
I don't want trails, just the stars however it's something I've not tried as yet with MF
If you want sharp stars then you need either:
- a short enough exposure time (e.g. max exposure time ~= 1000 / focal length) to avoid the apparent movement of the stars to become more than 1 pixel (depends on focal length and sensel pitch and orientation to the sky from your geological position),
- or use a tracking device which moves the camera at the same pace as the stars, thus keeping them stationary, (but will blur the landscape),
- or resort to a software generated starry sky for your location and time, and make a montage.
The problem with short enough exposure times, especially when you use longer focal length lenses (which magnify the movement), is that you won't get enough stars to show up, especially when you shoot during dusk or dawn, or when there is a lot of light pollution.
To improve the number of stars you can record during a short exposure, you can register multiple exposures and add them in a composite, although that won't solve the lightpollution issue, and you'll have to mask out the terrestrial elements.
As for a software solution (when the clouds persist and you cannot shoot anyway), you could use a program like Stellarium
. You can stitch multiple segments of screen captures of the stars to achieve the same Horizontal field of view (HFOV) as you camera covered for the terrestrial elements, and by zooming in in the software, you can achieve a pixel resolution to match you camera's sensor. So if your sensor has a horizontal resolution or e.g. 7304 pixels, your stitched image should at least have that resolution. That means that, depending on your screen resolution (e.g. 1920 pixels) and a bit overlap for stitching, you could need e.g. 5 horizontal screen captures where each screen has roughly 1/4th of of the HFOV of the final image, and some 4 rows (assuming Landscape orientation).