NGC4945 slightly more frames

kinetic (Steve) · #1 23-03-2009, 12:35 AM

Hi,

this result from tonight.
More frames compared to my Mar 17 result.
Tonight's stack was 159 frames.
Also, let the RA drift a bit and captured some
frames of NGC 4976.

4945 again looks ok right now on the dome CRT but I suspect it's
noisy on an LCD monitor.
Lots more frames needed to drop the noise floor.

Steve

JD2439975 (Justin) · #2 23-03-2009, 01:48 AM

Hey that's looking much better Steve.

Getting some nice structure appearing now.

Quark (Trevor) · #3 23-03-2009, 01:47 PM

Definitely better Steve,
You have some nice structure in 4945 and the more signal you get the smoother it is going to be.

Trevor

kinetic (Steve) · #4 23-03-2009, 09:59 PM

Hi,

thanks guys,
Tonight I tried a combine of the Mar 17 frames and
the Mar 22 frames.
The combination brings back the dark frame artifact but
waters it's effect down a bit.

I also discovered that saving a JPEG with ZERO compression and
keeping a crop just below 200kB, I get rid of a lot of the noise.
Der!...

It's obvious that even saved as a 5% compression JPEG contributes
a lot to the noise. Funny how such an obvious thing right at the end
of a large processing routine can trip me up!

Steve

spearo (Frank) · #5 24-03-2009, 07:28 AM

well done
focus might be a very slight bit out? Using a Bhatinov mask?
frank

JD2439975 (Justin) · #6 25-03-2009, 01:30 AM

Very noticable difference to noise in that last image, way less.
And that's with only 5% compression!! must remember that for future reference.

So Steve, any plans to put colour filters in that DSI ?

A Bahtinov mask yes...must make myself one of those.

Garyh · #7 25-03-2009, 07:18 AM

Lookin good Steve! Getting images nice under 200k can be a challenge ex with lots of stars or background noise.
Now some color