summer Messiers by moonlight

[nytecam]

Despite 93% moon due south in Libra and twilight in NW skies - no worries - this is electronic assist viewing

Used 12" SCT@ f/3.4 + SX Lodestar-Mx2 cam + LodestarLive [LL] s/ware in exosures from 5s - 30s unfiltered.    Skies too bright for 45s exp = whiteout

Reused the 'darks in LL from session 3 nights ago and perfect for removing hot pixels from the uncooled camera. No flats used.

So first shots of summer with Altair my goto star for Dumbbell M27 and OC M71 and PN NGC 6781 in Aql rising in ESE - do miss the colour in these PNe    Earlier M57 in twilight - amazing ! and nearby M56 GC.

[Martin Meredith]

Great shots -- the Dumbbell especially. Good to hear that dark re-use worked. I must give that a go too although the steep temperature gradients we're experiencing here at the moment (daytime 27C to 10C at night) may cause a few problems with that approach....

Martin

[nytecam]

Thanks Martin - I don't know how to save/reuse darks.

When last used LL 3days ago I didn't 'close' it and on clicking the LL icon last night at scope the prog was up and running with 3x30s stack 'dark' still there so I just carried on imaging seemlessly.  Contrary to Paul's advice I use a 3x30s dark stack for 5s - 45s exp with little ill effect

ps: did you notice on my last YT vid demoing LL the red background to LL?  Used the 'night option' in Cartes du Ciel and it transfers to LL to keep obsy as dark as possible - white laptops screens bounce around the dome back into the big scope   

[Martin Meredith]

Thanks Martin - I don't know how to save/reuse darks.

When last used LL 3days ago I didn't 'close' it and on clicking the LL icon last night at scope the prog was up and running with 3x30s stack 'dark' still there so I just carried on imaging seemlessly.  Contrary to Paul's advice I use a 3x30s dark stack for 5s - 45s exp with little ill effect

ps: did you notice on my last YT vid demoing LL the red background to LL?  Used the 'night option' in Cartes du Ciel and it transfers to LL to keep obsy as dark as possible - white laptops screens bounce around the dome back into the big scope   

Paul will correct me if I'm wrong, I hope, but I believe using the save and restore darks option will do what you want.

On this note, I have such a huge collection of darks now that when I get a moment I'm going to submit them to a statistical analysis to see just how much variation there is from one moment/night to the next. I'd be interested in exploring an approach mentioned in Berry and Burnell which allows reuse of darks -- or strictly -- thermal frames. Recycling seems to fit the spirit of electronically-assisted viewing.

Interesting finding about the red background. Since I'm always observing outside (no obsy) I don't usually bother, but on the one occasion I used LL at a dark site I did black out the screen completely during the exposure (didn't seem to make much difference though).

Martin

[Paul81]

A great session of shots there! You are making me feel very guilty for being lazy this time of year and packing up until the longer nights return. Perhaps if the sky is clear after one of the late World Cup games i'll head out...

Martin is correct, the save / restore will do exactly what you want and it should all work fine (fingers crossed... haha). Glad to hear the app has a prolonged execution test.. I do run static code analysis and also memory test with valgrind at points during development and so there should be no memory leaks...

I saw true red night mode in your video. Adding this officially would actually be very easy thanks to the QT framework. I think I would have to then force the video display to be mono (with a conversion from RGB to luminance) and then shade it red. You would lose live colour but get a nice dark friendly display.. I can even make it completely fullscreen too so avoid Windows / OSX program bars etc bellowing out stray light. Maybe a feature for the future?