M13 - 80ED - 1000D

[evil_yoda]

Hi all,

Here's my first go at M13, and also my first attempt at guiding.
Quite impressed how well it tracked considering I didn't spend much time on polar alignment and used all the defaults in the software.

Taken with an EOS 1000D (unmodified), 80ED and a HEQ5. Guiding with an ASI120MM-S and an old 50mm vixen refractor.
About 40 mins of subs of random length and ISO, as I was just playing around with PHD2 and the guiding really.

Any tips on the best exposures and processing to maintain some colour in the stars for M13?
Also, how do you know when to stop with making the background black?  Dark looks good, but loses detail in the object.
 

Matt

[tooth_dr]

That’s an excellent image! 

[evil_yoda]

12 hours ago, tooth_dr said:

That’s an excellent image! 

Thanks tooth_dr.

I think I'm gradually getting the hang of stacking and processing. Looking forward to the longer nights now to get more subs to play with.

Matt

[tooth_dr]

1 hour ago, evil_yoda said:

Thanks tooth_dr.

I think I'm gradually getting the hang of stacking and processing. Looking forward to the longer nights now to get more subs to play with.

Matt

Me too Matt. It’ll be nice to start imaging after tea instead of after bedtime. 

[Rodd]

 Amazing is right regarding the guiding quality--not bad at all for the time spent in fiddling (which can eat up the darkness fast).  as far as the blackness--remember, space is not black.  The optimum level is something you feel.  In photoshop I am told 23/23  is a good level (I don't use PS and don't really know what that number means).  Noise will undoubtedly control the level though--as you drop the black point, noise in the background is hidden.  I can see where you are loosing some stars around the periphery of the cluster.  Depending on what processing software you use, there are ways to reverse this (Masks, Layers etc).  Star color is a tricky thing--you are using a OSC setup, so you are a bit more limited as far as data collection.  But again, processing software allows you to isolate the stars and increase or decrease saturation.  It doesn't take much--stars are not like glowing Christmas lights (well, most aren't--the garnet star in IC 1396 not withstanding!).  A little color is all you need.  The trick is getting the stars to be colored throughout their profile, and not just along the rims--a bit of convolution can help smear the color out--followed by deconvolution to sharpen them up again.  You are in a mansion with a million interconnected rooms....take a left!

Rodd

[evil_yoda]

3 hours ago, Rodd said:

 Amazing is right regarding the guiding quality--not bad at all for the time spent in fiddling (which can eat up the darkness fast).  as far as the blackness--remember, space is not black.  The optimum level is something you feel.  In photoshop I am told 23/23  is a good level (I don't use PS and don't really know what that number means).  Noise will undoubtedly control the level though--as you drop the black point, noise in the background is hidden.  I can see where you are loosing some stars around the periphery of the cluster.  Depending on what processing software you use, there are ways to reverse this (Masks, Layers etc).  Star color is a tricky thing--you are using a OSC setup, so you are a bit more limited as far as data collection.  But again, processing software allows you to isolate the stars and increase or decrease saturation.  It doesn't take much--stars are not like glowing Christmas lights (well, most aren't--the garnet star in IC 1396 not withstanding!).  A little color is all you need.  The trick is getting the stars to be colored throughout their profile, and not just along the rims--a bit of convolution can help smear the color out--followed by deconvolution to sharpen them up again.  You are in a mansion with a million interconnected rooms....take a left!

Rodd

Hi Rodd,

Thanks for the great advice.
I used photoshop and some astronomy actions as I'm not a photoshop guru, though learning lots by playing around with it.
I'll look into the 23/23 number regarding setting the 'blackness'.

There was quite a lot of background noise as I probably didn't have enough consistent subs to really be able to push the image too much I think. 

Just waiting for some clear skies to get some more subs now 

Matt