The EQ3 DSO Challenge

[jjosefsen]

Last weekend I had an amazing 3 nights in a row to image - so I almost doubled the number of imaging sessions I have had since trying AP.

Lots of lessons learned:

• Not having a goto system and having to "man handle" the scope to slew it to targets, has a very negative impact on PA.
  • I suspect the flimsy tripod of the EQ3 has something to do with this..
  • I had achieved a very good polar alignment with Sharpcap before imaging, at the end of the session I did a test with Sharpcap again and the PA had gone from "Excellent" to "Fair" (the actual numbers are lost as I can't find my notes from that test..)
• Securing the drawtube with the focus lock screw on the SW ED80 shifts focus a bit, otherwise it holds focus quite well!
  • Another reason to get the motorfocuser..
• I need to get better cable management!!
• APT is a pretty good piece of software..!
  • The pointcraft utilities in APT are so handy for someone like me without goto, as when I'm starhopping to my targets, I can solve a 10 sec snapshot and have the coordinates and FOV shown to me in Cartes du Ciel or Stellarium.
• Got some valuable experience on getting data over multiple nights.
  • GOTO will make this much much easier.

Saturday and Sunday were particularly good, monday had quite a bit of wind, but I managed.

Gathered some more data on M33, initial measurements by PI seems to show it being superior to my original data, so my capture is progressing.

All in all I managed to get data on:

• M33 (Triangulum)
• B33 and NGC2024 (Horse head and Flame)
• NGC7023 (Iris)
• NGC7380 (Wizard)

Quite a haul that is.. Unfortunately I have a very limited view of the sky from my site here at home, so I can't get as much data on one object pr. session as I would like.

I have attached a preliminary edition of my Flame and HH image, because we need more pics dammit!

Found this one quite hard to process, it was very noisy, possibly because it is so low in the horizon, and I completely mucked up the framing and had to crop heavily.

 

Good night!

Edited January 14, 2018 by jjosefsen

[Art Gecko]

4 hours ago, jjosefsen said:

I have attached a preliminary edition of my Flame and HH image, because we need more pics dammit!

And a very nice pic it is too!!

I haven't posted anything for a while as I changed job and now have early morning starts to deal with, so my free time for imaging has been compromised. What few sessions I've had over the last months I haven't really had great results... in fact to start with I thought I'd broken something when trying to image M74... this is 33 mins @ ISO1600 (can't remember the sub lengths, probably 1min) didn't realise just how faint this target is!!

Next up was the triangulum galaxy... 58.5 mins this time in 30sec subs ISO1600... I thought this one would be a bit brighter but I was pleased to have captured some of the red nebulosity within the galaxy...

And finally, with Orion taking centre stage in the early evening sky, I had to get the obligatory M42 shot... 55.5mins in 30sec subs @ ISO800... might give this one a reprocess at some point as I feel the background is too bright, maybe because it's a HDR target and I've only done one set of fixed length subs, so could probably do with more data and longer sub lengths.

Enjoy, Art.

[Stub Mandrel]

11 hours ago, jjosefsen said:

I have attached a preliminary edition of my Flame and HH image, because we need more pics dammit!

Great  capture of the fainter nebulosity.

[Nigel G]

One I have been trying to get N/B data on. 

Finally got just over 2 hours Ha 13x600s  Hopefully tonight I can carry on with the OIII, only have 2x600s so far. Might be a bit of cloud dodging tonight though.

Soul nebula & a crop.

I have left a reduced red in the image, I think it looks slightly better but thats my preference  

Nige.

[Peco4321]

Horsehead and Flame, 162 x 45 sec, darks bias and flats, and yes, I am still struggling to gain anything from flats.  Un-modded canon 1100d on 150p, ISO 800.  Going to carry on with my news years resolution of trying to perfect flats!

[jjosefsen]

Im not sure that is something flats can cure (assuming it is the bottom right you are talking about), looks more like light polution to me..

[Peco4321]

4 minutes ago, jjosefsen said:

looks more like light polution to me..

Could well be, shooting over houses with conservatory lights, looking out towards the light skies of Hull. 

[jjosefsen]

2 minutes ago, Peco4321 said:

Could well be, shooting over houses with conservatory lights, looking out towards the light skies of Hull. 

I dont know what you use to process images, but PI, Star tools and I even think PS has tools to help remove this, could be worth as shot as it is very invasive.

[Peco4321]

Just GIMP, need to invest in better software when I have a better laptop. 

[jjosefsen]

1 minute ago, Peco4321 said:

Just GIMP, need to invest in better software when I have a better laptop. 

Aaaah ok..

[mikey2000]

Peco,  good work!    I  think this part of Orion is my all time favourite....   My first visit was to look at the flame nebula. It came out unexectedly well and also included a dim horsehead too.  I suddenly felt i was imaging with Hubble.    For Joe Public, that horse-head nebula is one of those not-very-well-known but recognisable DSOs.  Your friends *will* be impressed.

 

Keep trying with the flats - they make a very big difference if you get them right.   Are you still worried they are making your pics worse?

[Peco4321]

7 hours ago, mikey2000 said:

Are you still worried they are making your pics worse?

Yes a bit, something is not quite working with my flats (I have other threads ongoing on this issue) so I'll go back to basics and start at collimation etc and see how it goes.  

Overall though, I'm still very pleased with what I can get with modest equipment and processing skills/software. 

[wimvb]

1 hour ago, Peco4321 said:

Yes a bit, something is not quite working with my flats (I have other threads ongoing on this issue) so I'll go back to basics and start at collimation etc and see how it goes.  

Overall though, I'm still very pleased with what I can get with modest equipment and processing skills/software. 

Nice image of the Horsehead. The gradient is due to light pollution. A filter will make it less, but probably not remove all of it. Gimp doesn't have tools for AP as PS does, but you could try the following crude method.

Make sure your image is not clipped. You need to replicate the gradient in some way (that's what DBE in PI, and Gradient Exterminator in PS do), and Gimp has a gradient fill tool. You could try using that.

Sample two colours with the eyedropper tool. One becomes the foreground colour, the other the background colour. Create a new empty layer. Use the gradient fill tool to replicate the gradient in your image. Then subtract the two layers. Make sure this doesn't clip the image. You may need to do this in several small iterations, rather than one big swoop. It most likely won't remove the gradient completely, but it may make it less intrusive.

I think there should be enough cloudy nights even where you are, to give you time for this kind of experimentation.

Good luck.

(Btw, I haven't tried this myself. There's always a risk that it won't work at all. )

[Peco4321]

Enjoyable, but very cold session last night, bit of high cloud kicking around and light pollution seems to getting more and more noticeable for me now.  Not had time to add any flats to these but quite pleased to be picking out the blue areas in the Whirlpool Galaxy:

Beehive Cluster - 31 x 45 sec ISO 1600 plus darks and bias

Double Cluster - 34 x 45 sec ISO 1600 plus darks and bias

Leo Triplet - just a final flurry before packing up so only 10 x 45 sec, darks and bias, right in the worst light pollution area at them moment

Whirlpool Galaxy - 78 x 40 sec (for some reason I changed it!) ISO 1600 plus darks and bias, heavy crop

All stacked in DSS, and stretched in GIMP.

[jjosefsen]

Nice! Those seem a lot better. What focal length are you imaging at?

[Peco4321]

4 minutes ago, jjosefsen said:

Nice! Those seem a lot better. What focal length are you imaging at?

From what I've seen about my scope it's f/5. 

[jjosefsen]

1 minute ago, Peco4321 said:

From what I've seen about my scope it's f/5. 

That would be the focal ratio.

fratio=focal length/aperture.

is it a skywatcher explorer 150p?

[Peco4321]

2 minutes ago, jjosefsen said:

skywatcher explorer 150p?

Yes it is. 

[jjosefsen]

1 minute ago, Peco4321 said:

Yes it is. 

I have one of those as well. ? but mine is getting sold of. Again - nice images, I particularly like the M51..

[Nigel G]

750mm focal length 

[Stub Mandrel]

Despite by best attempts at screwing up and a guiding graph that was usually showing a horrible DEC peak on it, I managed to get 17 600-second Ha subs of the rosette last night. This morning I discovered that the DEC worm mount had come slightly loose. I'm going to fit a shim to keep the right spacing so I can tighten it down hard. In the end it has only spoilt less than a quarter of the subs.

I lost more subs to the ST4 lead getting hooked over the DSLR, tightening up and rotating the camera several degrees during each exposure!

[jjosefsen]

32 minutes ago, Stub Mandrel said:

Despite by best attempts at screwing up and a guiding graph that was usually showing a horrible DEC peak on it, I managed to get 17 600-second Ha subs of the rosette last night. This morning I discovered that the DEC worm mount had come slightly loose. I'm going to fit a shim to keep the right spacing so I can tighten it down hard. In the end it has only spoilt less than a quarter of the subs.

I lost more subs to the ST4 lead getting hooked over the DSLR, tightening up and rotating the camera several degrees during each exposure!

Sounds like one of those nights! ?

[Stub Mandrel]

Well this is the Ha (which was very noisy...) and the ha combined with my RGB data:

 

[jjosefsen]

@Stub Mandrel

Do you have any plans to upgrade either mount or camera? And if so, which one first?

If you don't mind me asking.

Gonna peep pixels when I get to my pc later

Edited January 25, 2018 by jjosefsen

[Stub Mandrel]

Just now, jjosefsen said:

@Stub Mandrel

Do you have any plans to upgrade either mount or camera? And if so, which one first?

If you don't mind me asking.

I buy a lottery ticket every week.

Hard question.

My original philosophy is to achieve as much as possible with relatively basic kit. Only when I start hitting the limitations of the gear, rather than those of my own skill should I consider upgrading.

The limited opportunities for imaging have me thinking I can't justify nearly £800 for a HEQ5 GOTO - anything smaller wouldn't be enough of an improvement and I'm not particularly convinced by quoted capacities (I think these are based on the capacity of steppers to cope with imbalanced loads and the supplied counterweights rather than any real engineering limitations).

It's harder to think what would be a worthwhile upgrade in terms of a camera. A more recent EOS might be worth it, but then all the stress of modification with the risk of bricking it...

Alternative would be a large sensor cooled astro camera, but then the cost is even higher. Definitely OSC as I feel imaging is getting too complicated already, if the moon hadn't been up yesterday I would have done unguided shorter subs, just for a quieter life. I don't want  the complexity of a filter wheel and the extra costs of all those filters.

Scope wise, I feel I have more than enough options and quality, especially with a 400mm x 66mm ED scope coming together.