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View Full Version here: : M17 Swan Nebula - no thanks to my brain


Screwdriverone
15-07-2013, 09:19 PM
Hi Everyone,

What a debarcle I had on Saturday Night, :screwy:

My wife bought me a heater to use out at the scope after last week when I almost froze while imaging....everything was fine and toasty for a bit while I dodged and waited for clouds to clear....

After some pretty mucky subs in a sparse region I decide to point at something bright and selected the Swan/Omega/Checkmark etc.... Every sub came up dim and the previously spot on guiding was going CRACKERS????

I looked up and thought I had some high mist or fog, but the stars were so bright, nope, that wasnt it....??? I checked PHD, BRIGHT stars yet the graph was going nutso??? What the?

Wait a minute.....I realised the scope was pointing West over my table whereas it was previously Southish....hmmmm. I turned off the heater. Whammo, PHD flatlines.....DOH! :rolleyes: heat turbulence ....:sadeyes:

Took some more subs, still crud, can barely see the Swan or the Trifid or anything, checked the sky, no mist, checked the guidescope, that is fine.......o hang on.....looked into the scope......primary OK, secondary is dewed over!......what a SPAZ!!!!!

So I grab the new heater and point it into the Newt to clear the secondary, NOW the primary instantly dews up.....FAR OUT, what a knob I am.....then finally, I put my brain back in, grab the 50mm dew heater on the finder scope and wrap it around the secondary and turn it on full blast....voila.....no dew in 20 seconds.....YAY!!!! Oh wait, the Primary is still fogged up......I wander inside to make a coffee, 3 mins later, I return and the primary is now clear......wonder of wonders!

So, after further 45 (9 x 5) mins of now clear imaging I packed it in as I was freezing again and found myself staring at my new heater, soooo tempted to turn it back on.

Soooo....here is the Swan. :sadeyes:

I'm such a numbnut

Here (https://www.dropbox.com/s/34do286pio99zt2/Omega%20Neb%20ST%20processed.png) is the dropbox version

Cheers

Chris

Lee
15-07-2013, 09:55 PM
I feel your pain.... dew.... I get maybe 30-60min, then the histogram starts exiting stage left.... I just made a dew shield for my newt today as my secondary keeps fogging.
Hoping the dewshield will do it, plan B is a heater on the secondary and a new fan on the primary....

Nice image BTW! :)

seeker372011
15-07-2013, 09:57 PM
Nice story. Been there done that :)

Rod771
15-07-2013, 10:12 PM
Nice image Chris :thumbsup:

Ah your too hard on yourself. I was very lazy on Saturday night, I set up (visually) with intentions to image but came in had pizza and lost motivation :rolleyes:

I did image though, went back out, slew to the moon and snapped away with the iphone :P

Peter Ward
15-07-2013, 10:22 PM
Nice duckie :)

Screwdriverone
15-07-2013, 10:23 PM
Thanks Lee, I have 2 spare ports on the dew heater so I am thinking of making up a Nichrome DIY heater for the secondary. I do have a DIY shield but I didnt use it.....



Lol, yup Narayan, thought I had lost it for a while there.



mmmm Pizza, thats what I should have done instead....:D

Cheers

Chris

Screwdriverone
15-07-2013, 10:24 PM
LOL, thanks Peter :)

Cheers

Chris

Larryp
15-07-2013, 11:36 PM
Very nice, Chris :thumbsup:

astronobob
16-07-2013, 02:18 AM
LOL Chris, good to know Im not the only one going around in circles some nights ;) at least you didnt blow anything up hey :lol:
Glad you got something good for your efforts, I like it a lot mate, well done and enjoyed your honest humour champ :thumbsup:
Gotta 'ave a better night next time :)

multiweb
16-07-2013, 07:06 PM
Nicely done Chris. Some pretty cool details up close. :thumbsup:

Ross G
16-07-2013, 08:14 PM
Nice shot Chris.

I like the colour.


Ross.

LewisM
16-07-2013, 08:18 PM
Dew, what dew? :) NEVER had the objective dew up yet, and the shield does NOT vignette the field either.

I use a Martec HV8000 heater (no fan). Just a SLOW gentle warming. Stopsthe guidescope dewing over (and oddly, not ever had the Takahashi finder dew over, heater or no heater)

Screwdriverone
16-07-2013, 10:59 PM
Thanks Laurie :D



Cheers Bob, sometimes you have to laugh at yourself, especially when you sit there scratching your head like a spaz wondering what is wrong....;)



Thanks Marc, the Atik gets up all personal like in the nebulas face....I am going to try my focal reducer next time out, to see how that goes too :)



Thanks Ross, :D



I really should have put my camping mattress dew shield on Lewis, I have been out 4 times this month with high dew all over the scope and didn't think the secondary would even fog up as I don't think I have ever seen this happen on the 8" newt so far.... with only a 56mm secondary, the standard Kendrick mirror heaters are too big, so I might have a go at making one.

Cheers

Chris

E_ri_k
17-07-2013, 09:00 AM
Great story! Sounds kinda familiar somehow:rolleyes: Good to see you got some decent subs in the end at least! Turned out well.
Erik

Screwdriverone
19-07-2013, 08:15 PM
Thank you Erik,

Looking again, it seems I may need to loosen the primary clips, may have some collimation issues to sort out after my primary mirror clean recently.....hmmmmm

Cheers

Chris

frenchbluehour
19-07-2013, 08:43 PM
I agree with Rod.. Chris you are too hard on yourself :) nice image

Screwdriverone
19-07-2013, 09:11 PM
Gee thanks Nicole, :)

Cheers

Chris

Shiraz
19-07-2013, 10:54 PM
worth all the trouble Chris - very nice smooth image. regards ray

E_ri_k
20-07-2013, 08:41 AM
I removed the primary clips on my old reflector and siliconed the mirror in. It made a pretty big difference.

Erik

Screwdriverone
21-07-2013, 06:29 PM
Thanks Ray, the Atik seems to really shine on Nebulae... :)



Not a bad idea Erik. I will see how it goes once I spend some time looking at it.

Cheers

Chris

strongmanmike
21-07-2013, 06:33 PM
Love the story :doh: :lol: (may as well laugh about it now) and the result is quite good considering. Why do you think your primary clips are a problem?

Mike

Screwdriverone
21-07-2013, 07:02 PM
Cheers Mike,

Its a theory, really, based on the recent cleaning of the primary and that I had thought I had collimated it OK, but it may just be some dodgy subs with eggy stars, I noticed some northwest, southwest elongation of the stars, so I am thinking that....

Am I off track?

Chris

stardust steve
21-07-2013, 07:37 PM
haha i got a chuckle out of that. Good to see you could still image in the end.
Dew and collimation are two big areas i still need to address for my 8" blue tube. :rolleyes: one day...

Screwdriverone
22-07-2013, 07:27 PM
Yeah, I know you have been there too Steve. :)

Sometimes I think I should just stay inside and watch TV, lol.

Cheers

Chris