Low-tech LMC

alocky (Andrew lockwood) · #1 02-11-2013, 05:52 PM

I headed out last night for some visual observing from my dark(ish) site, and almost as an afterthought threw the DSLR and polarie into the car.
Here's a stack of 15x2 minute subs of the LMC with the D800 and a 180mm prime at f3.2. The 180mm does a great job framing it.
It was very windy - so much so that I felt a bit vulnerable up the ladder of the big dob. I suspect this is the main cause of the elongated stars and not the limitations of the polarie or the alignment.
Astrobin is down for upgrades - so here's a link to flickr.
http://www.flickr.com/photos/photon_...7636744333685/
Cheers,
Andrew.

gregbradley · #2 03-11-2013, 01:08 PM

Nice fine resolution Andrew. The stars look fine shapewise. Are you able to get some more colour out of it as it appears to be a bit monochrome.
DSLR's have a tendency to display stars as white. Not 100% sure why that is except perhaps small wells (D800 wells are bigger than a KAF8300 though).

Data is probably there and needs some extra saturation. Nice detail of the whole LMC.

Greg.

DavidTrap (David) · #3 03-11-2013, 01:25 PM

I'm pretty impressed with the detail too!

Might have to try a mosaic with my FS-60 and QSI583 in due course...

DT

renormalised (Carl) · #4 03-11-2013, 02:26 PM

Nice

IanP · #5 03-11-2013, 04:43 PM

Quote:

Originally Posted by alocky

I headed out last night for some visual observing from my dark(ish) site, and almost as an afterthought threw the DSLR and polarie into the car.
Here's a stack of 15x2 minute subs of the LMC with the D800 and a 180mm prime at f3.2. The 180mm does a great job framing it.
It was very windy - so much so that I felt a bit vulnerable up the ladder of the big dob. I suspect this is the main cause of the elongated stars and not the limitations of the polarie or the alignment.
Astrobin is down for upgrades - so here's a link to flickr.
http://www.flickr.com/photos/photon_...7636744333685/
Cheers,
Andrew.

Nice shot Andrew

Roughly, how far away is your dark(ish) site

Larryp (Laurie) · #6 03-11-2013, 04:48 PM

alocky (Andrew lockwood) · #7 03-11-2013, 07:21 PM

Quote:

Originally Posted by gregbradley

Nice fine resolution Andrew. The stars look fine shapewise. Are you able to get some more colour out of it as it appears to be a bit monochrome.
DSLR's have a tendency to display stars as white. Not 100% sure why that is except perhaps small wells (D800 wells are bigger than a KAF8300 though).

Data is probably there and needs some extra saturation. Nice detail of the whole LMC.

Greg.

Thanks Gregg - I've spent a bit of time using excalibrator to balance the colours before giving the saturation a hefty kick. Although there's now a pleasing amount of yellow stars in there now, the overall green/blue colours just don't seem right. I suspect without H-alpha sensitivity on the chip the nebulosity is never going to be the right colour, although I might just leave the thing running all night next time and see if it improves with more data. Here's the astrobin link to the full-res version.
http://www.astrobin.com/62545/
Otherwise, I'll just have to stump up for a camera-lens compatible front for the QSI and go after this properly too!

Quote:

Originally Posted by DavidTrap

I'm pretty impressed with the detail too!

Might have to try a mosaic with my FS-60 and QSI583 in due course...

DT

I'm going to have to go the wide angle route with my QSI too I think. I'm certainly not modding my D800...

Quote:

Originally Posted by renormalised

Nice

Thanks Carl!

Quote:

Originally Posted by IanP

Nice shot Andrew

Roughly, how far away is your dark(ish) site

Hi Ian - it's about 90 minutes (legal!), 120km drive from near Murdoch out towards York. Not bad for imaging, but is a bit limited for visual due to local seeing. We have mains power, kitchen facilities and toilets. Let me know by PM if you want to come out!

Quote:

Originally Posted by Larryp

Thanks Larry!

DavidTrap (David) · #8 03-11-2013, 10:11 PM

Lenses on a CCD are great fun. Much easier night guiding at 200mm vs 1000mm plus!

I'm sure I've said this before, primes are much easier to use than zooms. The change in effective back focus caused by filters can really stuff up the optics.

DT

LewisM · #9 03-11-2013, 11:40 PM

Now that's a corker!

alpal · #10 04-11-2013, 12:59 AM

Hi Andrew,
It's a really nice image.
I hope you don't mind? - I did a little processing on it
& have attached a small version.
When the channels were split there was plenty of all 3 colours RGB.
I used LAB colour & also curves.
The red of the Tarantula etc came out.

cheers
Allan

alocky (Andrew lockwood) · #11 04-11-2013, 01:27 AM

Quote:

Originally Posted by alpal

Hi Andrew,
It's a really nice image.
I hope you don't mind? - I did a little processing on it
& have attached a small version.
When the channels were split there was plenty of all 3 colours RGB.
I used LAB colour & also curves.
The red of the Tarantula etc came out.

cheers
Allan

Not at all! That's delightful. Would you mind explaining what you did in a little more detal?
Cheers,
Andrew

alpal · #12 04-11-2013, 01:44 AM

Quote:

Originally Posted by alocky

Not at all! That's delightful. Would you mind explaining what you did in a little more detal?
Cheers,
Andrew

Actually - here is a crop just of your picture's Tarantula area.
Maybe I'll explain tomorrow.
Do you have Photoshop?
In the meantime check out Louie's videos here:

http://www.youtube.com/channel/UCJ5b6pFHBGe66vsuSaXb-0A

cheers
Allan