multiple nights, different durations?

[animaal]

I have images of a single target, taken over two nights.

The first night, I took 6-minute subs. The second night, I took 7-minute subs. I made sure to take flats and darks both nights. Everything was ISO800, so I have a master bias image that should do for both sets of images.

From reading other threads here, it looks like a good process would be:

1. Use BPP separately on each night's images (lights, flats, darks), with the "calibrate only" and debayer options enabled. This will give two separate sets of calibrated images

2. Run Star Alignment once over the combined sets of calibrated images.

3. Run Image Integration once on all the aligned images.


I'm wondering if this is the right approach for sessions with images of differing durations. Should I be using HDRComposition somewhere in the process? Even if it doesn't matter for a 1 minute difference, would it matter if the difference was longer (e.g. 5 minutes one night, 10 minutes the next)?

Thanks,
Martin.

[NGC7789]

From my understanding with sub exposures so close you're best off to just integrate them all together. If the subs were more different (like 2 stops or more) then you would benefit from HDRComposition. Of course you can also experiment for yourself. No harm there.

[animaal]

Thanks NGC7789, that makes sense.

I suppose I was just concerned that half the subs being 15% darker than the rest might mean they don't contribute to the final image.

I'll give it a go anyway!

[NGC7789]

the integration process will take care of normalizing the images to minimize noise.