Jewel Box and Becrux

kinetic (Steve) · #1 24-12-2010, 06:30 AM

Not quite first light with my new toy.....
This is about the 3rd or 4th night getting to know the
quirks of ED80 imaging with a DSLR.

I initially thought going wide field would be a doozy
after a few years with the DSI II/ 1500mm 12" newt combo
but how wrong was I!!!!!!!!

Firstly, these ED80s are a beautiful bit of gear, very easy to
get a decent pic from....but not without a bit of a humbling learning
curve first! Back to basics Steve.....focus, tracking, shutter shake,
mozzies, craning your neck, bumping the scope, GEM balance....mozzies
.....DUST BUNNIES...mozzies....

Secondly, as discussed with J, the field flatness doesn't look
too bad out to the field edges...might not need the FF?

The nights so far have been some of the worst for seeing and
buffeting gully breezes but the WF is a bit forgiving and the protection
of the dome is a godsend.

Can't wait for that moon to p--- off!

Comments welcome and suggestions from the ED80 gurus....
yes, yes, I know Mr Hoff, the sensor still needs cleaning

Steve

jjjnettie (Jeanette) · #2 24-12-2010, 09:35 AM

I think you may have shot at too high an ISO or you've over stretched in the processing.
Little is more when it comes to processing.

Hagar (Doug) · #3 24-12-2010, 02:23 PM

Nice result for a starting point Steve, This has to be a bit wider field than you are used to. I tend to agree that the ISO may have been a bit high and it may be worth stepping it down a bit and see what results you get. The main stars look a little fat and perhaps a little less exposure or a lower ISO will trim them down a bit.

Nice start though Mate.

Well done.

scopemankit (Chris) · #4 24-12-2010, 07:14 PM

You have taken one of the reddest stars in the sky, ESB365 (I think that is what it is called). You can see it just above beta Crucis. It can be a striking view, if there is no moon and good seeing, in a fair aperture telescope 14"+)

dannat (Daniel) · #5 24-12-2010, 10:25 PM

nice work steve, good to see you make use of it

OzRob (Rob) · #6 24-12-2010, 11:05 PM

The Jewel box is probably my favourite cluster. Unfortunately I can not see it from where I live now. Thanks for the photo.

I tried to use the Pentax K200D for astrophotography earlier this year but for what I wanted to do it was not up to the job. I see the same features in this image as I saw in my own. Most obvious are the amp glows along the top edge. You can also see in this image the vertical banding. If you stretch the image they are even clearer. Perhaps this is the reason why people are thinking that the ISO was too high or the image over-stretched.

I wrote a bit of a review on the suitablilty of the Pentax K200D for astrophotography.

kinetic (Steve) · #7 25-12-2010, 12:05 PM

Hi guys,
thanks for the help.

Thanks Chris for the heads up on that obvious red star.
I'd like to try an LRGB or RGB on that sometime with the DSI II Mono.

It does look terrible on the inside PC monitor, this gets me every time!
I will try ISO 400 next outing and I do know what you mean Rob about
the amp glow!
I also realised that this was a crop, about an 1/8th of the image is missing
from the right hand end and this is only because Neb won't display the
full 100% view of the FIT.
When I do scroll around the whole image there is noticable coma at the
edges.

Next night out might be with the QHY8 as well.

Steve

OzRob (Rob) · #8 25-12-2010, 10:32 PM

Quote:

Originally Posted by kinetic

Hi guys,
thanks for the help.

Thanks Chris for the heads up on that obvious red star.
I'd like to try an LRGB or RGB on that sometime with the DSI II Mono.

It does look terrible on the inside PC monitor, this gets me every time!
I will try ISO 400 next outing and I do know what you mean Rob about
the amp glow!
I also realised that this was a crop, about an 1/8th of the image is missing
from the right hand end and this is only because Neb won't display the
full 100% view of the FIT.
When I do scroll around the whole image there is noticable coma at the
edges.

Next night out might be with the QHY8 as well.

Steve

I was wondering why you didn't have the glow in the top right-hand corner!!..

kinetic (Steve) · #9 26-12-2010, 12:45 PM

Rob,

here's the full image with a severe curve to bring out
the amp glow(s)?

It pretty closely matches your K200 results as you said

Also, a full frame with a gentler curve showing the coma at frame edges.

Steve

kinetic (Steve) · #10 28-12-2010, 07:51 AM

Another two results, this time with ISO400.
30 sec frames for both again.

My main set was a failure, I took approx an hour of M42
only to find the focuser had slipped...all results way out of focus!

Steve

jjjnettie (Jeanette) · #11 28-12-2010, 09:10 AM

That's a pretty speccie 6 minute Eta Carina Steve.
Shame about that focuser trouble you had with m42.

kinetic (Steve) · #12 29-12-2010, 01:16 PM

Thanks J,

it's a worry when you seriously consider processing a badly unfocused
M42 set when that is all you have from the night out.

Anyway, here is a preliminary, rough LRGB of that very red star next to
Beta Crucis/ Mimosa. Imaged at 1524mm fl.
Chris says it is called ESB365 (still have to get off my bum and check this).

edit: yep, EsB365 it is....it and many other Carbon Stars mentioned in this thread:
http://www.iceinspace.com.au/forum/s...ad.php?t=39221

Very tired after an all-nighter....seeing was terrific. Lots to still process.

Steve

kinetic (Steve) · #13 30-12-2010, 09:19 AM

I did a better job of aligning the LRGB.....I must have bumped
the camera while switching filters, the lum was rotated a fraction
from the RGB.
Gets rid of most of the misalign halo in the red channel.

Steve