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M20 - Trifid Nebula

Gina

By Gina
in Imaging - Deep Sky

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Gina

Gina

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Had a go at the Trifid Nebula last night. Looked good at first and I took 30 odd lights of 2m at ISO3200 and -1C with guiding but when I examined them this morning I found nearly half of them were too poor to use. Either thin cloud or mist has spoilt them. There was also a very heavy dew so that didn't help. Anyway here's the result of stacking and processing the 16 best frames together with 35 darks. I've yet to take flats.

post-13131-0-71820300-1343041288_thumb.p

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Gina

Gina

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Well done, Gina!

I thought this target is too low for UK skies

Mark

Thank you :) Yes, it is quite low - about 15 degrees above the horizon I think. That was the problem last night - mist over the hills. It crept up on me. There are quite few nights when it's clear low down.
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Beulah

Beulah

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Fantastic Gina, well done!

Love it all the more through your sharing of the progress you have made over time from the construction of your observatory to this image. Well caught! :) Please post the progress of this image once you have done the flats.

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Gina

Gina

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Fantastic Gina, well done!

Love it all the more through your sharing of the progress you have made over time from the construction of your observatory to this image. Well caught! :) Please post the progress of this image once you have done the flats.

Thank you :) I shall certainly be posting more Trifid images. I'm hoping to get some more data tonight. The darks I took last night while I slept went slightly out and the temperature drifted up to 3C - that's 4C higher than the lights. I haven't got automatic temperature control working yet I'll be taking flats this evening and probably some more darks later - it need to be almost dark as I have a bit of light leakage. I'll be sorting that out.
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Gina

Gina

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I agree its great to see the progress you've made/are making and this is a nice Trifid, look forward to the calibrated pic.

Thank you :)
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Spikey

Spikey

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Coming together nicely now Gina. I'd be seriously tempted not to go above ISO800 with your setup and see how that turns out the images - I think you may be very pleasantly surprised :)

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Gina

Gina

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Doesn't look like I'll be doing any imaging tonight - got some problems to sort out. In for a cuppa now and to take a rest. I may have another go at sorting out the equipment later but in any case it isn't looking good for the Trifid - I think the mist is coming in :( After a long night I guess an early night wouldn't be such a bad thing :D

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Gina

Gina

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Coming together nicely now Gina. I'd be seriously tempted not to go above ISO800 with your setup and see how that turns out the images - I think you may be very pleasantly surprised :)

Thank you :) With the cooling I find I can use ISO 3200 up to several tens of minutes but I can drop it a bit and use longer exposures. That's if I can get the guiding working as well as it was last night - it was really solid for a change :)
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Gina

Gina

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Gina.

Darks and Flats would work a treat on this.Camera noise and Vignetting,are the only artifacts that let the image down.

But at such a low elevation,thats no easy capture.(Nice one).

Mick.

Got the flats and should be able to get the right temperature darks later tonight. At least that's working :D
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Gina

Gina

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No joy on the Trifid last night - the mist came in before it was dark enough for imaging. Still have equipment problems which I hope to resolve today.

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ollypenrice

ollypenrice

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It's a great result, especially from so near to the North Pole!!! One of the loveliest objects in the sky as well.

What I might do with that first off is set the background sky to a more neutral value. In Ps (but I guess in other graphics programmes as well) you can sample the sky in three places where there is just background sky. (In Ps it's the Eyedropper tool.) You get a value for red, green and blue. I find about 23-23-23 for RGB is good, though I sometimes lift the blue a bit and some peole have the blue much higher, around 29 or 30. You can adjust the channels via the black point in Levels provided you have not clipped too much off during the stretching.

Olly

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Gina

Gina

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It's a great result, especially from so near to the North Pole!!! One of the loveliest objects in the sky as well.

Thank you :) I much respect your opinion :)
What I might do with that first off is set the background sky to a more neutral value. In Ps (but I guess in other graphics programmes as well) you can sample the sky in three places where there is just background sky. (In Ps it's the Eyedropper tool.) You get a value for red, green and blue. I find about 23-23-23 for RGB is good, though I sometimes lift the blue a bit and some peole have the blue much higher, around 29 or 30. You can adjust the channels via the black point in Levels provided you have not clipped too much off during the stretching.

Olly

Thank you very much for your advice :) I'll have a go at that. PS is the software I use :)
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Gina

Gina

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Well done Gina I loved imaging the Triffid such a lovely sight in the night sky heres hoping for more clear nights for you this week with out the dreaded fog or dew to put up with.

Thanks Mark :) Have to see what tonight brings - I think I'm all ready to go.
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Gina

Gina

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A good run tonight so far :) Turned the camera 90 degrees so it's now in portrait mode and found I could get most of the Lagoon in as well as the Triffid. Got 43 lights of 2mins at ISO 800 with guiding. The capture run was stopped by a computer problem and reboot needed. I think that will do for these objects and I'm thinking of tyring M16 now.

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Gina

Gina

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Thats a good shot on a really tricky target there Gina. Its currently about a foot below the top of a neighbours hedge for me.

Cheers John

Thank you John :) I did a calculation and found I could get the Trifid and the Lagoon in the same shot by turning the camera upright. So this work on the Trifid is continued in the thread on both.
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Gina

Gina

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I was having a go at this last night, and its not easy being so low. It will look much better once you apply some flats.

Yes, indeed it does :) I've had a fresh go at this with more data where I've also included the main part of M8, the Lagoon Nebula in the frame.
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