a quick NGC5128 with new stepper motor mount.

[kinetic]

Last night I tried, yet again, another variation on a vibration
dampening mount for my RA stepper.

Clear and steady conditions, no cooling turned on.

Not quite the best resolution of any of my previous 5128's but
not bad either. Lots of dust bunnies from a dirty CCD.
Another 'stand 10ft from the monitor' job. :P

Steve

[Ross G]

Looks good Steve.

Nice detail.


Ross.

[kinetic]

Thanks Ross,

Here is the same set but using FLATS!
I almost never use flats, I'd put that down to my stubborn belief
that the CCD is usually clean and there are no obvious vignette issues.

Well by lucky accident last night I started a set on NGC 6744 and went
inside to make a mid dawn cawfee.
When I came back out I had almost nil good subs of 6744 but 200 subs
of some very even grey cloud deck. :rolleyes::mad2:

They showed the dirty CCD very well. Ambient conditions were very similar
to the previous night subs, so I thought I would see if I could use
the cloud sets as Flats.

Hope I have this sequence right but then I did this:

Subtracted master dark from flats.
Made master flat.
Calibrated 29th march NGC5128 lights with 31 March master dark
and 31 march master flat.

Upsampled then stacked calibrated sets and stacked as normal.

Set without flats (29 march) image on left, Set with flats on right.
Master dark Centre, Master Flat right.
Quite amazed that the flats removed all traces of dust and even let me
sharpen a bit more aggressively.
Hmmm, maybe there is something in using flats after all :)

Steve

[Rigel003]

I can't imagine imaging without flats. Remarkably you seem to have no vignetting in corners, even when the flat is stretched severely. Just a slight gradient from left to right. Is this the full frame?

[kinetic]

Graeme,

yep the results are very close to full frame. Any crop is only due to tracking
errors making the edge untidy after the stack. I crop before doing curves.
The Flat is true-full frame as shown below.
You are right, there is a gradient when I do a more severe stretch on it.
I should have rotated the flat to match the dust pattern on the light.
(my final result is rotated to put North at top).

Steve

[Paul Haese]

Round stars Steve. Great view too.