Suburban spiral

[Peter Ward]

M&T sublimely deep image of this object is a pretty hard act to follow...particularly in a theatre where there are 4 million natives besotted with bright outdoor lights....anyway....

The image link is here (http://www.atscope.com.au/BRO/gallery387.html)

A back of the envelope calculation says I'll need at least another 10 hours or so of exposure with my "small RC16" :) to match the flux gathered from the venerable 20" ......then there is that skyglow problem....

Grizzles aside....I have to say I am very pleased with the 92mm field corrector...due a small registration difference, the image is just a few pixels off a full frame, yet the stars are beautifully corrected to the edge of the chip.

I departed from my usual processing and delved into PixInsight a tad more. I'm now a total convert for PI's registration and integration tools, which was used for the above dataset....

[clive milne]

Peter.. it is bordering on a criminal offence to operate your equipment from a site such as it is, in South Babylon.

[Atmos]

A lot of nice detail showing down to the core, looking forward to the RGB version :P

As for PI... One of us one of us :lol:

[Peter Ward]

Ta...getting there albeit slowly.



:lol:

That's a fair call.

Sadly for me, things are not improving. The (developer) Barbarians are literally at the back gate, with the local council recently approving 175 lots in a medium density development about 2km to my south west.

[gregbradley]

Great star sizes and shapes.

Looks good but on my screen there seems to be a slight dark halo around the galaxy. Any idea as to what caused that?

Greg.

[Peter Ward]

Yes...it's PI's DBE tool. Doesn't quite nail the background gradients around the objects it masks....could also be I'm not applying if correctly too! :)

When/if I get some more data I'm hoping not to push the background so hard to give a smoother and more even result.

A dark sky would make life so much easier :)

[Placidus]

Excellent result under the given skies. The faintest bits of the galaxy are all there, and the core is very sharp and detailed.

I remember when I first moved to Leonay, more than 20 years ago. There were market gardens, horses grazing in the fields, and the sky was dark enough. Now there's 3 new housing estates, the sky is bright orange, and you can read a newspaper in the garden at midnight. First galaxies and then narrowband became impossible. You've probably noticed your sky getting brighter by the hour, as it goes from rural to suburban. Here at the farm, the local towns of Orange (45 Km, 41,000 souls after the mining boom), and Dubbo (120 km, similar size) are distant patches of light on the horizon, but Sydney (310 km, 4.3 million) is still the brightest.

[clive milne]

And Peter.. there is one more criticism I feel inclined to level. (call me churlish if you will)

1365
Eta
Horse head
253
et al....

As good as you have rendered them, they are all low hanging fruit, thrice picked.

[Peter Ward]

Thanks. I suspect a rural plot will also have to be much higher on our agenda if I am to see what this RC is truly capable of.



I suppose one of the problems I have is it takes me a while to "dial in" a new instrument...hence the images of well worn standard candles.

Frankly the RC isn't quite there yet.

I suspect there are small focal plane orthogonality errors (or collimation...hard to nail down) that I'd like to fully understand and account for...but are hard to quantify unless the seeing is reasonable. I've had tantalizing glimpses of imaging Nirvana: 5 micron stars across my 16803 sensor.

In my defence they also help me establish whether the instrumentation or my technique are capable of delivering A-list results or are simply an expensive folly....but rest assured, I'll move onto something a little more esoteric in due course :thumbsup:

[gregbradley]

I figured it was a masking issue or perhaps flats a tad off (slight mismatch with the darks and flats).

My CDK vignettes a lot even at dark skies but yes 10X worse in some light pollution. So near perfect flats and everything matched and even then testing them to make sure seem vital. Its one of the optical compromises the Planewave guys have made in exchange for lesser aberrations elsewhere. But it can be a pain.

At Ricks tutorial he mentioned not to do too many sample points for the DBE tool. Perhaps it works better before any permanent stretching as PI works on non linear adjustments for a lot of its tools and a stretch sounds like a permanent adjustment. Rick would know the best procedure. I think the screen transfer function to brighten then the DBE before stretching may be the go.

Greg.