Galaxy M105 and Friends

[Macavity]

After a few days of increasing frustration (swearing!) finally had the whole observatory

(mount, focus, "finder cam") and Watec under (30m) remote control from the lounge.

I then forgot and left the camera gain FAR too high - So there are hot pixel "tracks" on this.  

But since it's the first image in ages: 8" / F4 + 100 x 10 sec + (too much) post processing: 

Interesting region to revisit? Rather cute, more distant, spiral (ngc 3389) at lower left.

Latest casualty is my nice 10" 4:3 monitor which has suffered in the damp / salty air...

But it recovered slightly? There has to be SOME motivation for remote control, right?

[Macavity]

Well, it had to get better, Right?

Here's last night's effort - With rather *less* gain, a little added gamma etc.

Also (finally!) learned how to subtract *DARK* files. Onwards and upwards?

Now I need to work on removal of the errant "space junk" from the picture! 

[DoctorD]

Looking good - once you have got the hand of stacking you'll want to have a go at using curves in Photoshop, then it's a slippery slope to the dark side.

[Macavity]

Yes, I reckon it does need "curves" (e.g. alternating with "levels") etc.

"Level" cutting on the left side of the "histogram" removes the sky background well enough, but attempting to s-t-r-e-t-c-h things, via a right hand limit, eventually produces a comb-like distribution in the greys - Manifest as the "blocky" structure in the image. The price we pay for having (typically) only eight bits, I sense.

Recently I have become a lot more "conservative" re. adjusting the hardware camera controls. I leave the brightness and contrast mid-range. The "gamma" adjustment is held to be of limited value (Mostly just "adds noise"?) in the Watec! I sense the 100 frames (here) is the minimum needed for useful gain from stacking. Whether this should be 100x10s or 200x5.12s etc. (or more!) remains to be established. With limited memory for such things, I rather hope to find a "standard prescription" for these settings...

Interesting "test" object. Randomly comparing my "20min wonders" with...

http://www.kopernik.org/images/archive/n3389.htm (Obsy 20" F8 Ritchy Cretien!)

and

http://www.astronomersdoitinthedark.com/index.php?c=139&p=492 (8" SCT at f/5.6)

The latter taking ELEVEN hours at the canonical mountain-top-idyll!

We'll ignore the fact that my 8" / F4 Newt collimation still "squints like a...",

(suitable / amusing epithet escapes me!) - But ONE thing at a time? 

[DoctorD]

I've just watched a few tutorials on Photoshop processing - my ham fisted use of levels and curves are a thing of the past. <br />

<br />

Repeated use of small curve adjustments, tweaking the contrast at very specific points in the image can make a huge difference. <br />

<br />

Like you I hoped to find a "universal' setting for my SDC435 but found that tweaking was always necessary to get the best video output. <br />

<br />

Using the lodestar now is a lot easier, however I still need to play with the levels and gamma to get something worth looking at. Paul's lodestar live is great but it is fully manual. 16bit resolution means you can stretch it much further before you get artifacts in the image. <br />

<br />

CS<br />

<br />

Paul

[shirva]

glad to see you getting out again chris..im still stuck indoors with cabin fever due to clouds,rain,sleet,snow and high winds

[Macavity]

Thanks, Davy. Yes a couple of reasonable nights - May you get better ones soon too? 

Patchy cloudy out there at the moment, so sitting this one out. Getting picky already!