MW Panoramas: Optimizing time for foreground images
9 months ago
I am mostly shooting tracked MW panoramas and have started using longer focal lengths (85mm) end of last season. While the increased detail is definitely an upgrade, one of the challenges is how to deal with foregrounds.
For the sky I typically take about 5x5 rows/columns, so I need at least 1 foreground row @5 panels. At that long FL though, this takes forever since the DoF is quite shallow. I have tried different approaches (see below), but in general always end up losing about an hour for the foreground alone. Since the MW core is only visible for a few hours even in peak season, I'd much rather dedicate more of that valuable time to the sky images. So I am wondering if there are any methods to optimize foreground imaging?
What I have tried so far:
- Long single exposure per panel, e.g. F5.6 5 mins, focused on hyperfocal distance for max DoF. in-camera NR activated (works quite well against hotpixels) but doubles exposure time, e.g. 5 min x 2 x 5 panels = 50 minutes. This seems the fastest but it is still slow, F5.6 is still too shallow and close objects are soft.
- Wider aperture like F2.8, no in-camera NR and focus stack. At 85mm F2.8 though, I need at the very least 4 steps (and even that is taking huge compromises) to somewhat cover good focus across the frame. --> 3 min x 4 steps x 5 panels = 60 minutes
Comparing both methods, I guess focus stacking is delivering the better results. But I am stretching it with 3 min and the hotpixels. Ideally in-camera NR is activated but then I double the exposure time.
What I am considering to try next:
- Take foreground before MW core rises to free up more time for sky panels during 'core time'.
Concern: Usually I take sky first, then just switch off tracker and do foreground right away. This ensures sky and foreground are shot from exactly the same camera position and fit well. If the foreground is shot first, it will mean polar alignment still needs to be done before starting with the sky and it will introduce at least a slight camera repositioning - potentially even a tripod movement. Not sure if that is negligible or not, happy to hear from other users' experiences.
- Reuse the same foreground for multiple sky panoramas shot at that night
Concern: same as above, plus limits composition to that very location.
Comments and advice welcome!