Ngc253

[Peter Ward]

Also found this one rattling around the bottom of the hard drive... :)

http://www.atscope.com.au/BRO/images/ngc253psd.jpg

Peter

[coldspace]

Very nice, looks like something I could eat:lol:.

Matt

[skwinty]

Hello Peter
Great images.
I suppose one's critique of ones own work is directly proportional to the
capabilities of the utilised technology.
If any of your pictures were mine I would be ecstatic.
I only have a 12" gso newt, eq6 pro and a canon 40dh so I doubt if i would be at all critical (IF they were my images).
Keep them coming.
Regards
Steve:thumbsup:

[Rodstar]

I particularly like the outer halo that is apparent beyond the shape one usually sees with this object. Your image brings out the extent of stars and dust in the outer-lying regions.

Thanks for sharing yet another awe-inspiring image, Peter.

[spearo]

Beautiful
The thickness and colors just stand right out
lovely stars too!
frank

[Peter Ward]

Thank you gentlemen!

Admittedly, the image was very much a heavy artillery effort....which would have been so much easier if my backyard observatory was somewhere west of the Blue Mountains! .....but also testimony to the fact that CCD's can be used in very bright skies, yet still deliver tidy results....it's just a matter of exposure time...(no sales pitch here...just physics ;) ).

Now.....if these Sydney thunderstorms would just move on......Orion has just about set for another year!

[Hagar]

Great image Peter heavy artllery or not. A few years back NASSA would have had you on the payroll with images like this. It really sets the standards high for the rest of us mere mortals.

Great image

[Ric]

A fantastic image Peter, a very spectacular and well defined image of one of my favourite galaxies.

Thanks for sharing that one with us, it is very enjoyable to view.

[Alchemy]

youll have to have a hunt around the drive for some more... and once those storms clear get into imaging mode.

[marc4darkskies]

Very nice image Peter - nice depth and detail :thumbsup:. Definitely on my hit list!

Can't help feeling it looks a little too purple though (?)

Cheers, Marcus

[Geoff45]

Echoing Steve I'd have to say that I'd be ecstatic about taking a pic like this. However, I was wondering about the blue halos around the bright stars. Are these due to internal reflections in the camera? A bit of Photoshop work probably could get rid of them.
Geoff

[Peter Ward]

Probably a case of screen calibration....in any event I've tweaked it up a tad just for you Marcus :)

[leon]

Hi Peter, now that is certainly a brilliant image, however can I suggest that i find it a bit noisy, yea i know I'm sticking my neck out here, :whistle: but I'm sure you would prefer that rather than just saying it is nice, and think other wise, as you know I'm still learning, but need to be objective.

Maybe it is my monitor. :shrug:

Leon :thumbsup:

[Peter Ward]

It's O.K. Leon....there is some background stuff happening there, but not knowing what resolution/gamma levels people are running their monitors on I can only go with the screen in front of me....which tells me I mentioned the war, but may have got away with it! :)

[iceman]

Incredible resolution! Heaps of contrast in the outside dust lanes.. Beautiful image, Peter.

[robin]

Ah c'mon, its a hubble pic! (Seriously awesome shot Peter, well done)

[Bassnut]

OK, pretty cool, unusually flourescent, but given the gear, I some times see tiny vertical plumes on the dust lanes on other pics missing here?

[rat156]

Hi Peter,

I have a calibrated monitor and it's purple, definitely. Actually a bit fluorescent. Other than that, absolutely awesome.

Cheers
Stuart

[Alchemy]

just popped back for a couple of processing questions hoping you could share with us ( theres not enough discussion about this on IIS IMHO), being as it is definitely sharp but has a different look to it

during the processing did you use a high pass sharpening filter, not the variety in photoshop but one that sharpens just the high values, i think this is what makes it look different to me, i had a tinker with the one in WIN4AIP some time way back and had forgotten about it, i might have to have another play with it soon to see what it can do.

i noticed a sattelite trail to the lower right, what stacking mode did you use was it average mode, ive being using median of late although i usually run most of them just in case one gives a better result initially, ive personally found median is best about 80% of the time others swear by a sigma variety which might perform better in other programs than i have.

which brings me too how many exposures and length of time for each exposure and the camera.

cheers Alchemy

[Tamtarn]

Nice one Peter. Like to see you gather some new data on 253 in the future . Agree with some of the others its still a little purple on our LCD and CRT monitors and has vivid harsh blue halos around the stars. Maybe its OK on other monitors.

The weather in Sydney must be frustrating hope you get some clear skies soon to image some new objects :)

Barb

[Peter Ward]

I sum frames, as I have found median, SD clips etc, simply do not let you extract the full dynamic range from the data......like satellite trails !

I also use a high pass layering technique in PS3, so that just the fine detail is ramped up a tad.

Barb also made the comment the "stars have harsh blue haloes"....well, the two near the galaxy are certainly that...because they really are hot blue stars! :) you'll see elsewhere in the field the vary in colour, some yellow, some more white. I actively try to emphasize star colour in my images.

....Stars are never all white ;)

The image is a LRGB exposure, around 5 hours of data. If I shot from a dark sky, I could get the same S/N in about 1/3rd that time, and not have to deal with light pollution gradients......one the joys of deep imaging from the 'burbs' ! :)

I'm still playing with the data on this one, and appreciate the feedback. While I doubt I'll finally come up with a "one size fits all" version...this one's not quite done yet :)

[Geoff45]

Hi Peter
Are you sure they are not reflexion halos in the camera? This is certainly the case with beta crucius here (http://www.iceinspace.com.au/forum/showthread.php?t=29113) .
Geoff

[Peter Ward]

In the case of the Jewel Box image I have about a 15 magnitude spread between Beta Crux (mag 1.3) and the faintest stars in the image (according to The Sky/Hubble GSC around mag 16 ).... that's just shy of a million to one in brightness levels (!!) ....yep, there is some flare there! but given the dynamics I think the camera/scope did a great job ;)

As for Ngc253's close companions, CCD guru's much more skilled than myself have found them to be blue... so I figured, who am I to change them? :)

[Tamtarn]

I may be female Peter but I'm not stupid!!!

Yes I do know that there are different colour stars and they are not all white.

I didn't comment that the stars were the wrong colour just that they had harsh blue halos.

My point was that the stars in your image were very over saturated and compressed giving the harsh dark blue halo. They looked very unnatural.

I'm pleased to see you have reprocessed the data and they do look a little better now

Barb

[Peter Ward]

Jaaaysusssss H :) ...I didn't call anyone female or stupid so where did that come from?

None other than Jay GaBany also determined those little suckers are blueish.

Harsh blue? Duck-egg blue? I'm still trying to figure out sky blue......

[Satchmo]

This does come across as a little condescending. I can understand Barbs reaction. Wink emoticons can make a post look more condescending , intentional or not.. ;) ;) ( annoying arent they ! ) ;) ...... :)

[Peter Ward]

This was not my intent...which was "you already knew/understood that"..but agreed: better to use precise English.

[Kal]

Nice picture.

BTW - those stars definately don't have halo's around them. If you look at what a reflection halo looks like you will see it doesn't look like the blue around those bright stars. IMO, those starts look perfectly normal.

My only critique is the satellite trail, which detracts from the overall image a bit.

[Kal]

This can soooo be misinterpreted by many a male chauvinistic!!!!! :whistle::D

[Garyh]

Very lovely image Peter, sooo much detail in this one,
but I have to agree in what other have mentioned, being a little red in the background.
I gaussian blurred a small selection by 5 pixels that was rather free from stars and the red is up a little?
The diffraction around the brighter stars doesn`t worry me as I know its pretty unavoidable when you stretch your data hard to get the most from it.
But its a cracker image I enjoyed looking at!..:thumbsup:
cheers Gary