Sky Darkness

[Starwiz]

Does anyone start their imaging runs in Nautical Darkness rather than waiting for Astro Darkness?

I'm just wondering how dark the sky has to be before starting to image.

John

[DaveS]

For narrow band, yes, and perhaps even for the red channel if not too far from astro dark.

From mid May to mid July, nautical dark is all we have, and not a lot of that either  . Not helped by British Stupid Time.

[Marvin Jenkins]

Just for the purposes of learning, what is nautical dark? Never heard of it. From the reply by DaveS I am assuming it is the lack of really dark dark skies in the summer months?

M

[almcl]

Just to amplify KevS's comment,

Civil twilight:           the sun  is 0° to 6° below the horizon (after this it is Civil dark)

Nautical twilight (as per KevS) sun is 6° to 12° below the horizon (after this it is Nautical dark)

Astronomical twilight  sun is 12° to 18° below horizon  (after this it is Astronomical dark and the sky is judged not to get any darker)

And to answer the OP, yes lots of imaging in nautical darkness - otherwise there would be nothing to do from May till August, but rest of the year as well and see what the sky background measures when it comes to stacking.

[Starwiz]

Thanks for the replies.

I'm lucky to still have around 5 hours of Astro Dark in midsummer where I am now.

John

[alacant]

20 hours ago, Starwiz said:

imaging runs in Nautical Darkness rather than waiting for Astro Darkness?

Hi. Yes, absolutely. It gives you a chance to check focus, guiding and seeing. If all is well, you can add the frames to the rest. 

Cheers