Cygnus Loop - first attempt

[Gina]

It was too light really but here is my attempt from last night at capturing the Cygnus Loop with my wide-field camera and 135mm f2.8 lens. 47 lights of 60s at ISO 1600 but as yet no darks or flats. Stacked in DSS and processed in PS. Try as I might I was unable to derdge the Broom out and even the Veil was difficult. This is with an unmodded 1100D without cooling. The EXIF T started at 15C and rose to over 20C in the imaging run of about 50 minutes or so. Play stopped at around 2:15 when clouds came over. Clearly I need to do the filter mod on this camera and I think probably cooling too. I noticed the increase in noise as the sensor warmed up. And having seen what the 1100D can do at -15C the difference at 30-35C hotter is very evident.

[Earl]

Just had a quick play with this, hope you dont mind

[Gina]

Just had a quick play with this, hope you dont mind

Thanks No, I don't mind at all I could upload and link the TIFF produced by DSS if anyone's interested. Just remembered, I was going to do some flats today and some darks tonight.

[Earl]

Gina could you zip all the files and host it as I would like to have a more detailed play, if possible your bias master also.

[Gina]

Gina could you zip all the files and host it as I would like to have a more detailed play, if possible your bias master also.

I'll see what I can do. I've just finished a set of flats and I plan to take a set of darks shortly. I'll do a bias set too.

[Quatermass]

I took a crack at the broom last night Gina it is a faint subject to image, 80 subs at 90 sec iso 800 with 60 darks flats and bias was only just enough but the focus was out on all of the subs, my own stupid fault. I reckon 5 min or 3 min subs would be much better but I am going to wait for perfect conditions and have a go at it with my 200p.

[Steve Ward]

Hi there Gina ,

I am absolutely not the person to advise you on this as I cannot fathom PS myself ; but in my wanderings up the learning curve the other day i watched this tutorial , which looks to be aimed at just such an image as yours , being so full of stars.

http://www.astronomyshed.co.uk/forum/viewtopic.php?f=19&t=10593

Hope it's of some use to you,

Steve.

[Quatermass]

Have a look at this webpage Focal Pointe Observatory and scroll down to the bottom where you will find a link to a great action for photoshop that will select your stars for you in seconds, a little gold gem in the sea of on line tutorials

http://bf-astro.com/starSelection.htm

[Gina]

I took a crack at the broom last night Gina it is a faint subject to image, 80 subs at 90 sec iso 800 with 60 darks flats and bias was only just enough but the focus was out on all of the subs, my own stupid fault. I reckon 5 min or 3 min subs would be much better but I am going to wait for perfect conditions and have a go at it with my 200p.

Ah yes. I think it should fit in the frame from you 200p it's fairly small in the ED80 with FR.

It looks like being clear tonight and if it is I think I'll have another go at the Cygnus Loop with my wide-field setup. I did the filter mod on the camera this afternoon so it's more sensitive now. I'm currently taking flats at ISO 800 and 1600 with the 135mm lens at f2.8 with shutter speeds of 1/2500 and 1/4000 (the shortest). I might do some flats with the 55mm f1.8 lens later when it's less bright.

[Gina]

Hi there Gina ,

I am absolutely not the person to advise you on this as I cannot fathom PS myself ; but in my wanderings up the learning curve the other day i watched this tutorial , which looks to be aimed at just such an image as yours , being so full of stars.

http://www.astronomy...hp?f=19&t=10593

Hope it's of some use to you,

Steve.

Thanks Steve, I'll check that out

[Gina]

Have a look at this webpage Focal Pointe Observatory and scroll down to the bottom where you will find a link to a great action for photoshop that will select your stars for you in seconds, a little gold gem in the sea of on line tutorials

http://bf-astro.com/starSelection.htm

Thanks Mark Another one to look at

[Quatermass]

Its looking clear tonight fingers crossed, Hoping to have another go at the broom but this time with the 200p or mybe the Evostar if I feel like it I need to use it more then I do really. Any way heres to a nice clear night and some good imaging

[Gina]

Its looking clear tonight fingers crossed, Hoping to have another go at the broom but this time with the 200p or mybe the Evostar if I feel like it I need to use it more then I do really. Any way heres to a nice clear night and some good imaging

Amen to that Mark Still clear here ATM

The Peltier TECs have been sent off (Friday) so hope to get them tomorrow or Tuesday. Then I can fix my scope camera to give nice low temperatures again. I certainly miss a cooled camera! And I shall definitely be adding cooling to my wide-field camera - it makes so much difference. As I recall every 7C results in a doubling (or halving) of the noise level. So each extra drop of 7C means you can double the ISO or the exposure for a given noise level. ie. going from +20C down to -15C - a drop of 35C will give five stops lower noise. At 20C around 1m at ISO 800 is the best I do. I could go to 2^5 (2 to the power 5) minutes at ISO 800. That's 32 minutes at ISO 800 or 16m at ISO 1600. Now that's a huge difference! Seems too good to be true?? Well the results of my earlier testing where I posted a dark frame of one hour's exposure, show it to be true!

[Gina]

Tried imaging last night as it looked clear by eye and set up ready for imaging the Cygnus Loop again. Watched the sky gradually darken and started imaging just after midnight but I got one clear frame where I could see the Veil but then I guess thin high cloud came over because all but a handful of stars disappeared in a light fog Tried for a while to see if the high cloud would shift then went to other objects and they were the same M31 was totally fogged out, couldn't see M13 and M51 was visibly but foggy. I persevered until 1:30 then gave up! A disappointing night with absolutely nothing to show for it That's the way it goes sometimes I guess.

[Quatermass]

Sorry to hear that Gina it was like that the other night for me as well, just have to put it down to a practice session and get ready for the next clear night I guess. Got to say though I do like these summer nights makes a nice change not being freezing cold and dressed up like an Eskimo

[Gina]

Sorry to hear that Gina it was like that the other night for me as well, just have to put it down to a practice session and get ready for the next clear night I guess. Got to say though I do like these summer nights makes a nice change not being freezing cold and dressed up like an Eskimo

Better than winter - yes. Though I wouldn't call it warm last night - about 9C with a very heavy dew. I had the fan heater on in my warm room and a cardigan on myself. I must make a dew shield for my telephoto lens - had to wipe it several times last night.

[Quatermass]

Interesting, I did not get much dew at all last night and it felt quite warm, mind you I was at home set up in my back garden so once the camera was clicking away I went in the kitchen for a cup of cadburys hot chocolate.

Now processing the subs, got a some decent ones at last so hoping for a reasonable image out of them. I do have problems with dew forming on my secondary mirror though so after about 30 subs I blow the hair dryer on it just to make sure it stays dew free. Need to get one of those dew shields an old camping mat from a second hand shop would do the trick, happy to say the laser collimator worked great though.

[Gina]

Interesting, I did not get much dew at all last night and it felt quite warm, mind you I was at home set up in my back garden so once the camera was clicking away I went in the kitchen for a cup of cadburys hot chocolate.

Now processing the subs, got a some decent ones at last so hoping for a reasonable image out of them. I do have problems with dew forming on my secondary mirror though so after about 30 subs I blow the hair dryer on it just to make sure it stays dew free. Need to get one of those dew shields an old camping mat from a second hand shop would do the trick, happy to say the laser collimator worked great though.

Glad you got some imaging in Mark And that the laser collimator works well

TECs haven't arrived yet - hopefully tomorrow. Don't think the weather's going to be any good tonight anyway - there's rain forecast

Looking forward to seeing your processed image

[Anweniel]

Very nice Gina, the structure is all in there its the mass of stars that really washes it out a bit I think! Some more cracking imaging though and you're really getting the best out of these short nights

[Gina]

Very nice Gina, the structure is all in there its the mass of stars that really washes it out a bit I think! Some more cracking imaging though and you're really getting the best out of these short nights

Thank you Just need the clouds to go away at night

[astro mick]

Hi Gina.

Fraid i no nothing about DSLR,s,but your getting some good feedback here,so hope it will help.

Its a case of cant see the wood for the trees.

Still uncooled,very good.

Mick.

[MeyGray3833]

First attempts are a good indicator for when you do your next run. Usually it turns out way better. Good luck, be interested to see a finished result.

[Gina]

Hi Gina.

Fraid i no nothing about DSLR,s,but your getting some good feedback here,so hope it will help.

Its a case of cant see the wood for the trees.

Still uncooled,very good.

Mick.

Thank you I think the answer to the stars is to make a layer with the stars and use that to mask the image, then boost the nebulosity to bring up the wanted object, finally the stars can be put back. This is someting I haven't tried yet but I think will be needed for these faint objects "drowned" in all the stars of the Milky Way.

[Gina]

First attempts are a good indicator for when you do your next run. Usually it turns out way better. Good luck, be interested to see a finished result.

Thank you I'm looking forward to getting out there again and having another go. At least I've now removed the blue coloured (red reducing) filter and improved the sensitivity of the camera. Going by the weather forecast it looks like this misty, murky and sometimes wet weather will continue well into next week I'm hoping by then I might have received the parts required to add cooling to my wide-field camera. I think I may need to take two sets of data - the normal one and another with reduced exposure to get tight enough stars. Then remove the stars from the main image and add in the reduced star set. Alternatively, it may be that a lot more data without long exposures may contain enough of the faint data. It may require a much longer capturing run.