M17 - Omega Nebula SHO

[MarsG76]

Hello all,

Sharing with you my finished image of the Swan nebula imaged through SII, HII and OIII narrowband filter using my modded and cooled Canon 40D. Imagd trough my C8" SCT at 2032mm focal length.

Total exposure was 27 hours across multiple nights.

Clear Skies,

MG

 

[alan potts]

Great image, I didn't know you could do this type of narrowband work with a DSLR, something to consider.

Alan

[tooth_dr]

21 hours ago, MarsG76 said:

Hello all,

Sharing with you my finished image of the Swan nebula imaged through SII, HII and OIII narrowband filter using my modded and cooled Canon 40D. Imagd trough my C8" SCT at 2032mm focal length.

Total exposure was 27 hours across multiple nights.

Clear Skies,

MG

 

Amazing. What’s the Sii data like?  What sort of exposure times? Pretty remarkable is this image - the FL is long and the exposures must be long, and the image looks pretty tight 

[MarsG76]

57 minutes ago, alan potts said:

Great image, I didn't know you could do this type of narrowband work with a DSLR, something to consider.

Alan

Thats what the general consensus is, but the more I push against the flow, the better my 40D seems to perform... I think that cooling it is giving me a significant benefit because the subs were gathered at 4-5 degrees C where without cooling the length of exposure required for SII, being 1800s, normally heated the sensor to around 35 degrees.... and I never had as much signal in SII after stacking as I had now.

My original plan was to use my old 40D, than mod it and than upgrade to a mono CCD, but I'm still more than happy with my results from the 40D so I just keep on putting the CCD plan on hold... yes a mono CCD would shorten the sub length necessity but It doesn't matter since I have a permanent setup and literally adding subs night to night takes me about 10 minutes to resume the imaging... and would a CCD make that much difference with a 8" scope imaged at F10 or F6.3?

 

 

[MarsG76]

1 hour ago, tooth_dr said:

Amazing. What’s the Sii data like?  What sort of exposure times? Pretty remarkable is this image - the FL is long and the exposures must be long, and the image looks pretty tight 

Total exposure time was 27 hours.

HAlpha Subs are 10 & 15 minutes long, OIII subs are 15 & 20 minutes and SII subs are all 30 minutes so I had to spend at least 2 whole nights per filter, except in the case of SII which was 3 nights. The SII data is very good... much better now that I'm cooling the 40D than what I had in the past.

All subs are ISO1600 and the active cooling definitely helps with the noise levels, most noticeable with SII when comparing to my SII 1800 second subs captured in the past.

[alan potts]

Well hats off to the dedication you put into a fine image, I mean 27 hours, it's almost a day. I get a 071 next week so I imaging that could be used with filters too though as you said mono is the more accepted way here. I am actually thinking of banging the .63 reducer in the 12 inch SC and having a go at 15 sec subs just to see what I get. I was thinking long and hard about a CEM 120 for it and other scopes I have but sort of wonder if the 3 grand plus outlay was worth it with the difficulty of guiding 3M F/L.

Alan

[MarsG76]

11 minutes ago, alan potts said:

Well hats off to the dedication you put into a fine image, I mean 27 hours, it's almost a day. I get a 071 next week so I imaging that could be used with filters too though as you said mono is the more accepted way here. I am actually thinking of banging the .63 reducer in the 12 inch SC and having a go at 15 sec subs just to see what I get. I was thinking long and hard about a CEM 120 for it and other scopes I have but sort of wonder if the 3 grand plus outlay was worth it with the difficulty of guiding 3M F/L.

Alan

I wonder just how much quicker you'll be able to capture the equivalent with the 071... and whether 15sec subs will give you any of the deep nebulosity generally picked up by narrowband long exposure...

The 3m FL guiding will need to be guided via a OAG, for sure... but a good mount is essential, so if you are willing to spend the 3K on the CEM120, I'd say do it.. I feel like my CGEM is basically at its limit with 2m FL... than again who knows.. I'm constantly getting round stars even at the FL.

 

[alan potts]

Just now, MarsG76 said:

I wonder just how much quicker you'll be able to capture the equivalent with the 071... and whether 15sec subs will give you any of the deep nebulosity generally picked up by narrowband long exposure...

The 3m FL guiding will need to be guided via a OAG, for sure... but a good mount is essential, so if you are willing to spend the 3K on the CEM120, I'd say do it.. I feel like my CGEM is basically at its limit with 2m FL... than again who knows.. I'm constantly getting round stars even at the FL.

 

Oh on the SC I didn't mean narrowband work, just the odd globular cluster and the like, bright objects. As it is still on its fork I reckon 15-20 seconds is about the limit to keep it sharpish.

Alan

[MarsG76]

17 minutes ago, alan potts said:

I mean 27 hours, it's almost a day.

Thats over a day... but like I said, it's autoguided so time spent doesn't matter... the end result counts... I did spend over 56 hours on the Fighting dragons in Ara.. so the times can get quite high very easily. 

I like to collect the extra subs simply for the SNR factor.

 

 

Edited August 15, 2019 by MarsG76

[MarsG76]

1 minute ago, alan potts said:

Oh on the SC I didn't mean narrowband work, just the odd globular cluster and the like, bright objects. As it is still on its fork I reckon 15-20 seconds is about the limit to keep it sharpish.

Alan

In that case, yeah, no need, you should be fine.

 

[alan potts]

I can't get over how differnt the two image look, here is my not brilliant effort of a mere 3 hours

 

Difficult to believe it is the same area

Alan

[MarsG76]

4 minutes ago, alan potts said:

I can't get over how differnt the two image look, here is my not brilliant effort of a mere 3 hours

 

Difficult to believe it is the same area

Alan

I see the resemblance.... natural color is much faster to image...