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View Full Version here: : Bortle 6 - no LP Filter - Orion


astronobob
05-01-2019, 02:42 AM
Always been reluctant to doing mono - and wont be in the foreseeable future, PC's are frustrating Rgrds 'astro' for this duck..

This is actually the very 1st attempt at a deepsky target from the Cosmo-Caboose, should be called the 'smoCo caboose'.

So I spends a previous night guesstimating exposure limits amongst Bortle 6 skies without a LP filter taking subs between 1 & 3 minutes in 15 sec increments and found 2 mins to be reasonably showing the limit of faintest dust collectable without too much sky glow in the background. Other factors such as nearby clouds, atmospheric moisture, time of night ect I'd suspect would/should/could effect the exposure length on a given night ?

This image was taken through the 8" Orion F/4 , with the Baader MPCC and a QHY10 Color Cam @ -20 deg.
The stack consist of only 11 subs of 2 mins due to incoming white things floating around up there.

Notes made for Equipment: 1) MPCC Air-Gap not critical as only experimenting. 2) Collimation - not bad. 3) Chip Squareness to light path - not bad.
Operator of equipment :sadeyes: :o 4) Neq6p worked flawlessly.

Sky Conditions: Bortle 6; Seeing 3/5 top layer - 2/5 bottom layer; Cloud cover 30%; Humidity 85 %; 1 day prior New-Moon

Processing: DSStacker & PS CS3
Notes: Colour Gradients around perimeters due to excessive stretching in these 'outfield zones' attempting to find some or any signal.

Conclusion, can only go so deep with this gear & conditions - Next effort/opportunity will be adding LP Filter.

multiweb
05-01-2019, 07:33 AM
To get the outer faint stuff you might do 10min subs and a few hours of them. Also flat fielding will help reveal all the brown neb.

RyanJones
05-01-2019, 08:03 AM
Hi Bob,

I'm eagerly awaiting the filter image to see the comparison. I live in Bertole 7-8 skies and I'd like to be able image more from home. I'm looking forward to seeing the difference the filter makes.

Which filter are you planning on using ?

astronobob
06-01-2019, 02:19 AM
Yes Marc, 10 mins would turn out white frames with out filters :rolleyes: ;)
.
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Gidday Ryan, hmm Bortle 7-8 :eyepop: thought I had it tough :P
Will be trying with both a Omega DGM GCE Contrast filter & also a Baader UHC-S ?
Hope they turn up some interesting results - when the clouds-take-a-hike :thumbsup:

multiweb
06-01-2019, 10:32 AM
:lol: ha.... ok. I thought you were imaging from around Esk and Bortle was some kind of German beer. There you go then... you've got your flats sorted out. :P

Placidus
06-01-2019, 10:47 AM
Brave to attempt it from such a bright location.

There seems to be some vignetting. Are you using flats? You can do flats retrospectively and reprocess the image.

Even without that, your result is much better than you think: if you carefully model the non-nebulous background and subtract most of it (we had a go on a copy), you get a crisp dark (but not clipped) background and beautiful nebulosity.

Great stuff.

astronobob
07-01-2019, 01:52 PM
Ah Marc, your a worry, typical beer drinkers ;)
But yeah, never done flats or bias before to this day, tho should consider or atleast try them to experiment for comparisons.
cheers
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Hi Placidus,
I have never bothered with flats yet, tho should get around to it I believe. and yes, I was rather content with how the nebulosity processed out under the conditions, definitely some incentive for imaging 'with a color camera' from the suburbs.
Appreciate your comments there :thumbsup:

multiweb
07-01-2019, 02:02 PM
Flats will make a big difference with all your gradients. Didn't you use to image from around Gatton before?

astronobob
07-01-2019, 02:48 PM
Ill have to make a light box or similar, or try the ol 'T' shirt method for starters.
I used to have the 'Bob'servatory' out at Leyburn, 50klms NthWst of Warwick several years ago, sold it ! Bortel 1.5-2 skies, but problematic getting out there frequently enough to warrant the effort & generally not as dedicated as some/most :thumbsup:
Cheers ...

multiweb
07-01-2019, 04:35 PM
Get an electro Luminescent sheet (http://www.iceinspace.com.au/forum/showthread.php?t=169484). Got some USB powered ones. They're pretty cool, thin, light, easy to store.

astronobob
07-01-2019, 09:32 PM
Cheers Marc, just ordered one, within australia.
Thanx for your help :thumbsup:

RyanJones
07-01-2019, 11:41 PM
What a great idea. Can I ask where from in Australia ?

astronobob
08-01-2019, 05:12 AM
Try this link, I had to log in to get it, tho if no go, copy and paste the item description into ebays search window, should do it ?

https://www.ebay.com.au/itm/253749815559

multiweb
08-01-2019, 06:45 AM
Got mine here (https://www.ebay.com.au/str/bitb99)

RyanJones
08-01-2019, 10:52 PM
Thanks guys :thumbsup: