Bodes Galaxy

[ryandsimmons]

So after my "success" with the whirlpool galaxy, which was very recognisable and looked quite nice in 15 minutes worth of 30 second subs last night I decided to try doing everything properly.

I set up my scope, 2 st alignment plus 4 calibration stars. Polar aligned.  2 star plus 4 calibs again, another polar align (small tweaks at least that time.) 2 star plus 4 calibs AGAIN and started on my first attempt at Bodes Galaxy which was in a great spot in the sky.  I initially wanted M101 but I was worried that a neighbours upstairs light might just be in place to cause refelections into my homemade dew shield.

I initially tried for 3 minute subs, but it wasn't right with the stars ovoid, so I dropped to 90 secs and started.

What I got in the end I am extremely dissappointed with, I have a bright core, but pratcially nothing else, although if I saturate the image I can see there is data there, but I think not enough to bring out,  So my questions are:

1) Looking at these images have I done anything obviously wrong?

2) Will I be able to get anything out of these or should I scrap them?

3) Have I done everything right, but just chosen a tricky target?

Equip:

Celestron C8 on a CG5GOTO

Canon EOS1000d

55 frames of 90 secs, of which 45 are used.

12 darks

6 flats.

Stacked in DSS

Pros: I am learning.  This flats seem to have worked, with no vignetting like I usually get.  The wavy nature of the image is also reduced thanks to someone telling me yesterday here that I should be moving the scope every 5 frames r so by 20 pixels,

Cons: No galaxy.

3 pics here are what came straight from DSS post stacking, with the only adjustment being saved as JPG in Photoshop, another JPG where I upped the levels in photoshop, showing there is some glaxy, but I think not enough to be usuable.  And thirdly the whirlpool galaxy with had a third of the subs and a fifth of the total exposure, yet shows more detail????

Embedded is the the tif from DSS entirely untouched apart from resixed down from 68meg.

Boderaw by Ryan Simmons, on Flickr

Bode by Ryan Simmons, on Flickr

1505whirlpool by Ryan Simmons, on Flickr

Bodereduced.tif

[glowingturnip]

on the contrary, I think you've got a nice capture there actually, now it's down to post-processing, which is a dark art.

The key is getting the stretch right - the core of the galaxy is almost, but not quite burnt out, so don't lower the white point at all.  You can raise the black point until the background is dark, but not totally black, don't clip any of the black end off (on yours, you should crop off all the stacking artifacts round the edge first where the individual frames don't quite line up, which is totally normal, so that you can see where your true background is), then use the middle slider to bring out the detail.  

Hope you don't mind, but I did a quick and dirty stretch of your image here, there are many further things you can do to improve on this:

the core might be a bit tricky to manage, but you can see you've got lots of detail in the arms - a good capture !

[ryandsimmons]

Okay, that makes me feel a lot happier.

Can I ask sorry what settings you played with?

There are around 5 million in photoshop and the learning curve is a brick wall.  These black and white points I assume are in the levels?

I have looked at the PS guides around, but honestly they are pretty impenetrable.  However what I can now do is try to play around to end up with what you have done there so at least I have a target and know I am heading in the right direction.

On the negative side the vignetting is still there, so I need to look into that.  I have a feeling it is light pouultion from my neighbours upstairs window bouncing off the dew shield.  I will start looking at individual frames as I know they turned it off half way through the subs so then I can see if that is where this comes from.

[Owmuchonomy]

Hi Stuart, if you haven't done it already, search for Doug German on YouTube and follow his tutorials. They taught me so much about processing.

[glowingturnip]

yes, Levels in Photoshop, which has 3 sliders, a black one, grey one and a white one.  Don't touch the white one or the core will burn out, raise the black one till the sky is dark, but not black, and then lower the grey one to taste,  (I actually used Pixinsight above, but Photoshop Levels does the same thing)

Unfortunately, as if the capturing of the stuff wasn't hard enough, post-processing is another learning mountain.  I guess that's what makes it so satisfying in the end when everything starts coming right and you're getting results you're proud of.  Might be worth getting a couple of books which will go into processing - many people swear by 'Making Every Photon Count' by Steve Richards, and I think 'DSLR Astrophotography' by Michael Covington is pretty good too.

Don't worry about the gradient, there's always a gradient even after using flats, and yes, your neighbour's lights, the moon, streetlights etc etc will all contribute, but there are ways of dealing with that too 

[ryandsimmons]

And now that I have been pointed in the right direction I have had an epiphany moment!

Whereas I have been doing one thing at a time and moving onto other setting I can see now how they interact.

So a play around and I get this which I am extremely happy with....

Boderefined by Ryan Simmons, on Flickr

On another point thanks very much all for your patience.  I know I have been asking a lot of questions, I am astounded at how helpful and friendly everyone is in the face of it!

[glowingturnip]

excellent !

[datman]

Hi

I've just checked it using Nebulosity. As I suspected from my own attempts a few months ago, there's not a lot of data there.

After I stretched it the arms were not very evident.

Try some longer exps, 5 mins. You can combine these with shorter ones to avoid blowing out the centre.

[datman]

Same applies to M51. Here are two I did recently

, one a combination of 30 and 60 seconds (about x20)

the other 20 x 5mins

both using C8 with FR so f6.3

[datman]

Graphics handling on this BB is awful! I can't change the image above and now it won't let me add another.

The images of M51 above are from 20 x 5 minute exposures

[datman]

At last this is the 30 + 60 second exposure. See what I mean?

[datman]

Hi

Just checked your equipment, 60s is about the most you can do without guiding equipment, which you don't seem to have.

Sorry about that oversight