• Welcome to Orpington Astronomical Society.
 

News:

New version SMF 2.1.4 installed. You may need to clear cookies and login again...

Main Menu

Region around the cone nebula

Started by RobertM, Dec 08, 2011, 22:02:30

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

RobertM

Again hellish gradients to deal with with the moon another day older than the Rosette I posted but I don't think it come out too bad.  Noise was very difficult to control but I had a better handle on the background neutralisation so that helped.  The brown bits are slightly green but it's difficult to sort those out without processing them with a paint brush !

Optics: C11 Hyperstar @f/24
Exposures:  40 x 300s
Date: night of 5/6 Dec 2011
Captured/Calibrated and stacked in MaximDL, processed in PixInsight.



Lin k to full size image: http://farm8.staticflickr.com/7146/6478812691_8275868796_o.jpg

Robert

MarkS

#1
Robert,

That is a really impressive result from your location - especially with the moon to contend with.  It compares very favourably with mine taken a few days ago on a moonless night:
http://forum.orpington-astronomy.org.uk/index.php?topic=8003
(I was using a CLS filter, but only to kill annoying background gradients.  The CLS filter doesn't improve S/N in my location.)

The dust in your image is beginning to resolve quite nicely.  I also think I prefer your framing - you've captured some interesting stuff over on the right hand side.

Try resampling your image x2 and then binning x3 - this results in a 2/3 scaling but also increases perceived sharpness and reduces noise - I think it works well for one shot colour cameras because, on acquisition, they inherently "blur" the image due to the colour interpolation algorithm required by the spatial sampling of colour filter array.

That Hyperstar/SX-M25C is going to be a killer combination for colour imaging when you get it somewhere dark!  Bananascope watch out ...

Mark

RobertM

That's very kind of you Mark, I did think this was a bridge too far.  It's a far from perfect image but necessary good practice for when the moon is well out of the way later in the month.  I'd actually dialed in the Monkey head nebula but got my NGC numbers tangled; by the time I'd seen the first sub it was quite late so I just left it taking subs overnight.  I'm really looking forward to getting down to a dark site now !!!

The problem with the CLS is that although it murders light pollution it also kills signal strength and gives a horrible colour cast - have you tried something like a UHC filter instead?

Thanks for the tip, I'll try the resample and try a tinge of sharpening with the next process.

Robert

Fay

well you are having a bit of practice, Robert, & getting good results, especially with the Moon!

May go outside tonight, but not sure where to go as full moon
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

MarkS

Quote from: RobertM
have you tried something like a UHC filter instead?

I thought about it but haven't got around to doing anything about it yet!  In my location I can safely use a filter that doesn't cut so out so much of the spectrum.

RobertM

You're using a scope at f/2.8 so why use a filter that cuts most of the light out ? I'm having difficulty understanding why you haven't got a few LP filters for various conditions.

I have some you could try if you want including a Neodymium, LPS P2 and UHC (though that's more suited to where I am plus I'm using it).

Robert