Closeup Study of the Trifid: 19 Hours, 2.4m FL, 0.7arcsec/pix, Southern Sky Gems Obs.

Harel_Boren · #1 14-07-2015, 02:00 AM

Hi guys,

I think I'll name this series "The Classics" - the bright objects we all go through as beginners, never to come back again... thus leaving them deprived of the expertise gained through years of shooting and processing, and with somewhat better gear at that !

Kicking off with Centaurus A, then The Pillars of Creation, and now with the Trifid - these images share among them more than 60 hours of exposure from under pristine Kalahari Desert skies. Shooting them all again is, for me, an unexected treat

http://www.pbase.com/boren/image/160719068/original

I hope you like it, and any comments are, as always, very welcome.

Cheers,
Harel

gregbradley · #2 14-07-2015, 07:52 AM

Yes the Classics, a good name. You got a wonderful amount of detail there. That little finger coming off the top of the "hill" is the usual sharpness test and yours is very clear. Great dust detail as well.

Greg.

IanP · #3 14-07-2015, 10:40 AM

This photo of yours is really one of the greatest of the classics !!! Keep going with ‘em …

strongmanmike (Michael) · #4 14-07-2015, 01:27 PM

Yeah, not bad Harel...not bad at all, a nice close up of this perennial favourite! Nothing wrong with imaging the favourites even on a regular basis, particularly when you have new equipment to use and like a Bolognese sauce, each effort usually turns out different to the last

I particularly like the way you have shown some turquoise green in the reflection nebulosity, this is often missing from images of the Trifid and although I am not quite sure it is as strong as you have shown here? (could be?

)...it is definitely in the mix

Mike

multiweb (Marc) · #5 15-07-2015, 08:21 AM

Very cool shot. I like the image scale in the original. Top shelf.

Paul Haese · #6 15-07-2015, 08:57 AM

Nice image Harel. Heaps of detail to peruse and colour is good too (although maybe just a tad too cyan for my taste). I also wonder if you could do some more sharpening of the dust last lanes and the relativistic jets etc.

It's an interesting combination to use the 8300 sensor with the scope you are using. If you had the choice would you use a larger sensor? I have been considering my choices now that the flattener I bought does not work on the 11002 sensor. I had thought maybe going to the smaller 6303. Are you happy with this size sensor on that scope?

Harel_Boren · #7 15-07-2015, 01:50 PM

Quote:

Originally Posted by Paul Haese

Nice image Harel. Heaps of detail to peruse and colour is good too (although maybe just a tad too cyan for my taste). I also wonder if you could do some more sharpening of the dust last lanes and the relativistic jets etc.

It's an interesting combination to use the 8300 sensor with the scope you are using. If you had the choice would you use a larger sensor? I have been considering my choices now that the flattener I bought does not work on the 11002 sensor. I had thought maybe going to the smaller 6303. Are you happy with this size sensor on that scope?

Thanks Paul. I'm in a plane that's about to take off so will be short.
Re color I frankly didn't play with it at all. It's the absolute accurate cyan that came out of the balanced histogram.

Re the chip scope combination - it provides a very good for between pixel size and theoretical avg point size (5.4 micron and 6 micron, respectively), getting to the super resolution of 0.54 arcsec per pixel. This enables taking absolutely everything that the seeing can give. Imagine the pillars of creation image was processed at drizzle x 2 and then BROUGHT DOWN to 0.69 arcsec per pixel...
So if you have good seeing and good optics I'd warmly recommend going for this combination. Anything else will put you at the risk of undesampling - not a bright prospect given the capex and opex involved :-)))

Re chip size - it gives a handsome FOV for anything interesting to shoot at this scale, so very satisfied there too...

Hope this answers and ... All electronic devices must now be turned off

Cheers,
Harel

marco (Marco Lorenzi) · #8 15-07-2015, 02:10 PM

Lovely image Harel, the Trifid is still one of my favorite objects of the sky and you managed it very well. I don't particularly see a cyan dominant but I am currently using a non calibrated monitor, so I cannot be so sure. You must have some good seeing from Namibia, lots of details imaging at so high scale with several tiny stars on the background.. lovely..
Clear skies
Marco

EDIT: Just checked from home, with my calibrated monitor and confirm that to me too it has an excess of Cyan..

Paul Haese · #9 15-07-2015, 06:01 PM

Quote:

Originally Posted by Harel_Boren

Thanks Paul. I'm in a plane that's about to take off so will be short.
Re color I frankly didn't play with it at all. It's the absolute accurate cyan that came out of the balanced histogram.

Re the chip scope combination - it provides a very good for between pixel size and theoretical avg point size (5.4 micron and 6 micron, respectively), getting to the super resolution of 0.54 arcsec per pixel. This enables taking absolutely everything that the seeing can give. Imagine the pillars of creation image was processed at drizzle x 2 and then BROUGHT DOWN to 0.69 arcsec per pixel...
So if you have good seeing and good optics I'd warmly recommend going for this combination. Anything else will put you at the risk of undesampling - not a bright prospect given the capex and opex involved :-)))

Re chip size - it gives a handsome FOV for anything interesting to shoot at this scale, so very satisfied there too...

Hope this answers and ... All electronic devices must now be turned off

Cheers,
Harel

That is certainly something to think about Harel. Might have to get some adapters made up and give this idea a try. Seeing results from a scope of similar scale gives me a lot to contemplate. Thanks for the detailed response.

RickS (Rick) · #10 15-07-2015, 08:14 PM

A very nice M20, Harel. Definitely up there with the best of them.

Cheers,
Rick.

Harel_Boren · #11 21-07-2015, 06:25 AM

Quote:

Originally Posted by marco

Lovely image Harel, the Trifid is still one of my favorite objects of the sky and you managed it very well. I don't particularly see a cyan dominant but I am currently using a non calibrated monitor, so I cannot be so sure. You must have some good seeing from Namibia, lots of details imaging at so high scale with several tiny stars on the background.. lovely..
Clear skies
Marco

EDIT: Just checked from home, with my calibrated monitor and confirm that to me too it has an excess of Cyan..

Hi Marco,

I don't know... I have taken special effort to well balance the histogram, hence the cyan is just what's there... you may look at the histogram on the astrobin link here: http://www.astrobin.com/193962/ Looking forward to hearing your thoughts.

Cheers,
Harel