M31 Andromeda Galaxy from Qld Astrofest

[Ross G]

Hi Rob,

A great photo of a great object.

You have captured some amazing detail and some nice colours.

Ross.

[RB (Andrew)]

Very nice image of M31 Rob.

[venus (Lydia)]

Wow!

[RobF (Rob)]

Originally Posted by alan meehan

Stunning image good to see you got results through the fog and trees

Thanks Alan. All part of the AF fun

Originally Posted by alpal

Very nice pic Rob.

Can you please tell me what your gain & offset value you used for this pic?
I have a new QHY9 & I'm just wondering what other's are using.
It has been suggested that a gain of 11 & the offset 112 in EZYcap is a good starting point
but what would that be in MaximDL where the gain is expressed in percentage?

Hi - I shoot with 10 and 100 for unbinned with my camera. My dynamic range doesn't go all the way out to 65535, but with 16bit resolution it doesn't seem to matter too much. Tracking, noise, etc usually an order of magnitude more important

Originally Posted by Ross G

Hi Rob,

A great photo of a great object.

You have captured some amazing detail and some nice colours.

Ross.

Thanks Ross. I'm an M31 "tragic" must confess

Originally Posted by RB

Very nice image of M31 Rob.

Thanks Andrew!

Originally Posted by venus

Wow!

Cheers Lydia

[RobF (Rob)]

Originally Posted by davewaldo

Great work Rob, would love to see a larger version

Have loaded a full size jpg image onto Astrobin at:
http://www.astrobin.com/18679/


(egad - I didn't do a final crop!)

[alpal]

Rob,

Hi - I shoot with gain = 10 and offset = 100 for unbinned with my camera.
My dynamic range doesn't go all the way out to 65535, but with 16bit resolution it doesn't seem to matter too much.
Tracking, noise, etc usually an order of magnitude more important

Thanks - so you are using EZYcap?
That won't allow you to dither will it?
I of course have EZYcap but I want to use MaximDL so that I can dither
& get all the other goodies.
In Maxim the gain is expressed in percentage with no conversion
table anywhere which is a nuisance.
( a percentage of what? )

[RobF (Rob)]

Ummm, Maxim running QHY9 using ASCOM drivers, which in turn call the underly QHY driver I believe. 100/10 is what I have set for the unbinned section in the QHY drivers, if that makes sense?

Happy to PM some settings if that helps?

Dithering is extremely helpful, however you do lose time on each sub waiting for guiding to reacquire and stabilise. Its a worthwhile tradeoff for the reduction in noise and artefacts most would argue. I actually run Maxim via CCD Commander, and have CCDC set to only dither every 4th frame (so I dither just before the start of every LRGB sequence for example). Setting up image runs in Maxim always frustrated me, and CCDC will do auto-meridian flips and unattended imaging among other things as a bonus. Very powerful software at a decent price.

[alpal]

Originally Posted by RobF

Ummm, Maxim running QHY9 using ASCOM drivers, which in turn call the underly QHY driver I believe. 100/10 is what I have set for the unbinned section in the QHY drivers, if that makes sense?

Happy to PM some settings if that helps?

Dithering is extremely helpful, however you do lose time on each sub waiting for guiding to reacquire and stabilise. Its a worthwhile tradeoff for the reduction in noise and artefacts most would argue. I actually run Maxim via CCD Commander, and have CCDC set to only dither every 4th frame (so I dither just before the start of every LRGB sequence for example). Setting up image runs in Maxim always frustrated me, and CCDC will do auto-meridian flips and unattended imaging among other things as a bonus. Very powerful software at a decent price.

I found that when Maxim DL was used -
You first of all must close EZYcap -
you go to:
camera control window, expose, options , camera settings &
there you can set gain & offset but -
the gain is in percentage (offset the same as above).
The help file in MaximDL does not explain how to convert the RAW number into a percentage.


Maybe CCD commander is converting to the raw EZYcap settings for your QHY9 camera?
Isn't it better to dither every sub-frame?
That's what I used to do with a DSLR camera.
Forgive me if I sound silly but I only bought a
QHY9 a week ago & I've never used a mono camera before.
I am just trying to sort out all this stuff on my kitchen table.

[RobF (Rob)]

I'll PM...

[RobF (Rob)]

Sure you could dither between each L,R,G,B frame, but you're going to be stacking all the L's, R's, etc so not any point dithering on every filter change - better to do it so that each LRGB is dithered relative to last, if that makes sense? Saves having to wait for guiding to settle for 3 lots of dithering, which on a cheapish chinese mount is often around 15-20secs, if that makes sense?

[alpal]

Originally Posted by RobF

Sure you could dither between each L,R,G,B frame, but you're going to be stacking all the L's, R's, etc so not any point dithering on every filter change - better to do it so that each LRGB is dithered relative to last, if that makes sense? Saves having to wait for guiding to settle for 3 lots of dithering, which on a cheapish chinese mount is often around 15-20secs, if that makes sense?

OK - I have no trouble with my mount settling after dithering.
It's an NEQ6 & I have ADM saddle plates & parallax tube rings
with a 1.25" astro physics counter weight bar.
You can see it in my flickr photos.
That makes it much more stable.
It only takes 2 seconds to stabilise after dithering 4 pixels.
Therefore I dither every frame to cancel out hot pixels & get a smoother background.

[RobF (Rob)]

Yes, probably overkill to wait that long at 550mm focal length. Things a bit fussier through the Newt at 1000mm but even then I'm probably waiting a bit too long rather than risking any unnecessary movement. Sounds like you have a quality mounting setup too though Alan compared to my minimalist investment.

[Paul Haese]

Nice work Rob. I like the silkiness of the image, colour saturation and detail. It maybe just a little too blue but there is not much in that. I particularly like the blue stars in the arms.

[RobF (Rob)]

Originally Posted by Paul Haese

Nice work Rob. I like the silkiness of the image, colour saturation and detail. It maybe just a little too blue but there is not much in that. I particularly like the blue stars in the arms.

Thanks for that Paul. Yeah, I was a bit worried about a little too much blue and still haven't pulled off the creamy "yolk" centre I would have prefered, but I love the young blue stars in M31 and did work to bring them out. Somewhat "M42'ish" in that it doesn't let itself be processed easily.

[batema (Mark)]

It is one impressive looking galaxy. Love the star colours and I am going to have a crack at that next year as well as trying for the full 10 days. Looks great.

[allan gould]

Great image, Rob. I really like the colour and detail. Have yet to image this and forgot to do it at Astrofest but seeing yours makes me want to have a go.

[RobF (Rob)]

Originally Posted by batema

It is one impressive looking galaxy. Love the star colours and I am going to have a crack at that next year as well as trying for the full 10 days. Looks great.

Originally Posted by allan gould

Great image, Rob. I really like the colour and detail. Have yet to image this and forgot to do it at Astrofest but seeing yours makes me want to have a go.

Thanks guys. Good friend of my wife says guys are "always better with a project". M31 is often on my list when poking above the horizon. Just be aware the hours are often even more unsavoury than this year - AF was about as late as it ever gets this year and the moon was out of the way fairly early on. You frequently find in the last 2 weeks of July the moon may still be up for much of the first 6 days by the time M31 is at a decent image height (2 to 3am). Chance of fog, sleep deprivation and alcohol affecting imaging performance increases greatly during those hours!....

[Tandum (Robin)]

purple is the new brown. very nice rob

[naskies (Dave)]

That looks superb - great work, Rob!!

[RobF (Rob)]

Originally Posted by Tandum

purple is the new brown. very nice rob

Hmmm, actually it is a bit purple really. Its tough getting that last 10% of the image right. More reason for a Sidonio at some point

Originally Posted by naskies

That looks superb - great work, Rob!!

Thanks Dave - appreciate that.