M33 from Kelling - September

[Mike]

I have finally got around to processing my image of M33 from Kelling. It is 14 x 600 seconds with a Canon 1000D. I took darks but forgot to do the flats before removing the camera.

Although not a lot of colour has come through for some reason i'm fairly pleased with it, especially the detail in the spiral arms. Although it's obvious from the larger image that the scope needs collimating.



Larger version HERE

[Jim]

That's a nice sharp image Mike

[Carole]

Some nice detail there Mike.  

not a lot of colour has come through for some reason

Wonder what happened to the colour?

I notice your corner stars in the top corners are elongated but not those at the bottom.  I mention it because I have a similar problem with my Atik383 and wonder what the cause is.  If the flattener distance is wrong, wouldn't all four corners be affected, or could if be the camera is a bit heavy (especially in my case with the filterwheel) causing it to be ever so slightly crooked in the drawtube.

Very good for no flats, or did you do an artifical flat?

Carole

[Mike]

Carole I think the lack of colour was simply due to the relatively short exposure time. Either that or 10 minutes per sub was too long and this has caused the red in the Ha areas to become clipped and therefore turn white.

No I didn't do an artificial flat. I processed it with Darks and Lights only.

[MarkS]

Very nice result Mike.  Some good detail there.

The lack of colour is puzzling - I'm sure it's something to do with the processing.  If I perform a 4x4 bin and then increase saturation the galaxy centre is very distinct from the arms and the stars begin to become colourful.  However the H-alpha regions are barely red. 

Is this a modded camera?  What ISO were you using.

As you have noted, you do appear to have a slight collimation issue.

[Mike]

Mark, yes it is a modded Canon 1000D. ISO was 800. I have a feeling the central areas of the Ha regions were clipped after being processed and hence any saturation adjustments would make no difference.

I'll take a look at the pre-processed image and see where I went wrong.

[MarkS]

mark, yes it is a modded Canon 1000D. ISO was 800. I have a feeling the central areas of the Ha regions were clipped.

Best thing to do is to check an individual sub - you should then see what's going on.

[julian]

That's a nice  image Mike

[Mac]

Very nice image, love the detail,
cant wait to see the colour data restored.

Mac

[mickw]

Certainly got some nice detail

Was this with your Altair RC ?

[Mike]

Mick, yes it was. Nice little compact scope.

[Fay]

Good to see you getting an image again Mike

[Mike]

I processed this a few different ways again last night and there is in fact plenty of colour in both the stars and the Ha areas so this result was clearly due to my inexperience with processing. However the new results are a lot noisier. I will keep persevering. I'm actually enjoying re-learning the skills I've forgotten and learning new stuff related to DSLR processing (which is a totally different ball game to cooled CCD).

[Mike]

OK I tried again today using some different stacking and de-bayering techniques and this is the result. Far more colour, although it is noisy. I still have a lot to learn.

[JohnP]

Hi Mike - looks good especially the reprocess. I'm looking at it on a crappy screen and the blacks look very black (perhaps a tad to black for my liking). So having done both dedicated astro and DSLR imaging what are your thoughts...

John.