NGC253 & Alluna Unplugged...

Peter Ward · #1 16-10-2015, 03:25 PM

If I had a silver dollar....

More testing. Seeing was much better in the Shire last night.

This is pretty much a raw sub...as with changing optical configurations I don't
have flats yet without the AFFC attached (I was curious to see how it would fare without a field corrector)

So, only darks, gradient exterminator and some DDP to stretch out the data. Nothing else.
The link is here

Single 20 minute L frame.....It was the faint fuzzies in the background that could tempt me to go epic on the exposure times

gregbradley · #2 16-10-2015, 03:35 PM

That looks very good. Tiny amount of coma in the corners so the corrector just really handles those small amounts in the corners? I wonder if its worth it. What's the downside of the corrector - a bit of chromatic aberration perhaps or reflections?

Greg.

Peter.M · #3 16-10-2015, 04:29 PM

Quote:

Originally Posted by gregbradley

That looks very good. Tiny amount of coma in the corners so the corrector just really handles those small amounts in the corners? I wonder if its worth it. What's the downside of the corrector - a bit of chromatic aberration perhaps or reflections?

Greg.

He is waiting on an adaptor for correct spacings from memory

gregbradley · #4 16-10-2015, 06:09 PM

Quote:

Originally Posted by Peter.M

He is waiting on an adaptor for correct spacings from memory

Yes I understood that. I was commenting on the image which has no corrector and the resulting tiny coma in the corners (its hardly noticeable). No doubt he was curious as to the performance without it as RC design does not really require a corrector (Dall Kirkham does). A field corrector is probably not without its downside (reflections, harder to flat, maybe even slight vignetting).

In a large image from a 16803, those tiny slightly elongated stars will tend to round out with stacking and they'll be even harder to notice.

Certainly the image shows that with a smaller sensor there would be perfect stars across the field without the corrector and also that the corrector is not doing a lot and could be considered not essential.

Greg.

peter_4059 (Peter) · #5 16-10-2015, 09:16 PM

It's comforting to see you can spend a Brazilian and still not get round stars.

Atmos (Colin) · #6 16-10-2015, 09:19 PM

I am pretty envious of your setup there Peter

peter_4059 (Peter) · #7 16-10-2015, 09:32 PM

Thanks Colin. It's no Alluna but it does the trick.

Peter Ward · #8 17-10-2015, 10:30 AM

Got some good calibration data last night, allowing for some image processing of the the data....so I guess it's plugged into the hamster wheel
at present.

Guess I'll have to live with these bloated and eggy stars.... for now

Same URL as before

gregbradley · #9 17-10-2015, 11:27 AM

Its very sharp and detailed. Is this with the AOX? Did you add data last night as last night was poor seeing around my area and I assume around yours.

Greg.

peter_4059 (Peter) · #10 17-10-2015, 11:31 AM

The detail in the galaxy is impressive but what's going on with the bright stars? It's like a second set of diffraction spikes rotated 45 degrees?

Peter Ward · #11 17-10-2015, 12:01 PM

Quote:

Originally Posted by peter_4059

The detail in the galaxy is impressive but what's going on with the bright stars? It's like a second set of diffraction spikes rotated 45 degrees?

That would be due the fact I gamma corrected the proverbial out of them and that I use 65mm square filters, which do impart their signature "square" scattering.

Quote:

Originally Posted by gregbradley

Its very sharp and detailed. Is this with the AOX? Did you add data last night as last night was poor seeing around my area and I assume around yours.

Greg.

Yes, AOX guiding at 2Hz. I also got some more data last night but the seeing here was woeful....waste of time in the end.

marc4darkskies (Marcus) · #12 17-10-2015, 12:52 PM

Resolution looks excellent Peter - esp since you haven't done any decon! A stack of these in good seeing would be a treat!

Peter Ward · #13 17-10-2015, 02:00 PM

Quote:

Originally Posted by marc4darkskies

Resolution looks excellent Peter - esp since you haven't done any decon! A stack of these in good seeing would be a treat!

Ta Marcus.

I'm certainly being reminded that seeing makes a massive difference at these focal lengths.

Another clear + stable night would be good

alpal · #14 17-10-2015, 03:08 PM

Hi Peter,
that's an amazing picture from just one 20 minute frame.
It's gone very deep to show so many other galaxys.
I am surprised you can get this from a light polluted location.
The detail is also incredible.

Imagine what you could do with only one night of good seeing?

cheers
Allan

Stevec35 (Steve) · #15 17-10-2015, 10:57 PM

Looks very promising to say the least Peter. I'm glad you're up and running with the new toy.

Cheers

Steve

Paul Haese · #16 18-10-2015, 10:12 AM

That's more like what I was expecting. Excellent detail in the galaxy. Resolution is up there. Any chance of flipping it around, I keep having to rotate my head to see stuff I am trying to see.

Somnium (Aidan) · #17 18-10-2015, 10:44 AM

Great stuff peter, the scope is really performing well. this looks like a good candidate to go deep ! there are so many background galaxies that look like they would come up a treat when the SNR is increased and some colour data is applied.

codemonkey (Lee) · #18 18-10-2015, 11:00 AM

Damn... nice tight stars, awesome detail. Great work. I did 3.5hrs lum on this last night... if only I could get stars/detail that tight.

pvelez (Pete) · #19 18-10-2015, 01:55 PM

Looking good Peter

There are definitely plenty of faint fuzzies in the background - its worth the effort to take a deep dive into this one

Pete

Peter Ward · #20 19-10-2015, 09:56 AM

Quote:

Originally Posted by pvelez

Looking good Peter

There are definitely plenty of faint fuzzies in the background - its worth the effort to take a deep dive into this one

Pete

Thanks Pete...well ....Might take a while, with the current cloudy conditions plus waxing moon. I expect we'll have storms and hail when the right adapters later this week!

Quote:

Originally Posted by codemonkey

Damn... nice tight stars, awesome detail. Great work. I did 3.5hrs lum on this last night... if only I could get stars/detail that tight.

Ta. Have to say I'm very happy with the whole package...but like any telescope it's not immune to seeing which may not have helped in your neck of the woods (seeing here was light showers

)

Quote:

Originally Posted by Somnium

Great stuff peter, the scope is really performing well. this looks like a good candidate to go deep ! there are so many background galaxies that look like they would come up a treat when the SNR is increased and some colour data is applied.

Indeed, it was the background fuzzies that had me intrigued. Suffice to say
it's a work in progress now.

Quote:

Originally Posted by Paul Haese

That's more like what I was expecting. Excellent detail in the galaxy. Resolution is up there. Any chance of flipping it around, I keep having to rotate my head to see stuff I am trying to see.

Knew you'd come around. Photoshop>image>image rotation >180

Quote:

Originally Posted by Stevec35

Looks very promising to say the least Peter. I'm glad you're up and running with the new toy.

Cheers

Steve

Thanks Steve.

Quote:

Originally Posted by alpal

Hi Peter,
that's an amazing picture from just one 20 minute frame.
It's gone very deep to show so many other galaxys.
I am surprised you can get this from a light polluted location.
The detail is also incredible.

Imagine what you could do with only one night of good seeing?

cheers
Allan

Thanks for the feedback. One hopes!