NGC3372 - Keyhole Nebula with Ha enabled camera

[PhotonCollector]

Hi all,

here's one of my first images with my modified Canon EOS 300D. Great to see clear skies again - even if the Moon is about.

There's a higher resolution image here http://www.skylab.com.au/pmsa/ngc3372f.html

<TABLE id=table1 cellPadding=2 border=0><TBODY><TR><TD vAlign=top>Telescope</TD><TD vAlign=top>12-inch f/5 newtonian telescope</TD></TR><TR><TD vAlign=top>Guiding</TD><TD vAlign=top>hand guided with 4.5-inch guide-scope.</TD></TR><TR><TD vAlign=top>Camera</TD><TD vAlign=top>Canon EOS 300D Digital - Hα enabled.
</TD></TR><TR><TD vAlign=top>Exposures</TD><TD vAlign=top>6 x 120 second exposure @ ISO200 with
dark and bias frames removed and flat-fielded.
average of 3 x 120 sec. darks,
average of 10 x 1/4000 sec bias,
average of 6 x 1 second flat fields.</TD></TR><TR><TD vAlign=top>Total Exposure time</TD><TD vAlign=top>12-minutes.</TD></TR><TR><TD vAlign=top>Filter/equipment</TD><TD vAlign=top>Used Baader Multi-purpose Coma Corrector.</TD></TR><TR><TD vAlign=top>Sky Conditions</TD><TD vAlign=top>Seeing: 9.5/10, first quarter moon at meridian.</TD></TR><TR><TD vAlign=top>Ambient Temperature</TD><TD vAlign=top> </TD></TR><TR><TD vAlign=top>Notes</TD><TD vAlign=top> </TD></TR><TR><TD vAlign=top>Processing</TD><TD vAlign=top>Iris, Photoshop, Noiseware CE.</TD></TR></TBODY></TABLE>

[h0ughy]

Very nice Paul, so what do you think of the modded camera?

[PhotonCollector]

Well blue is no longer the dominant color signal that's for sure, instead its red - in fact very red. I think I will need a 2" Baader IR/UV cut filter.

Modifying the camera was less than fun, but after having done it and solved a number of trouble spots I wouldnt hesitate to do it again.

Paul M

[ving]

great stuff paul!!!
the shades the dark splotches, the lights, the stars... its all good :)

we have some great deep sky imagers here :)

[PhotonCollector]

Thanks for the comments Ving. I even impressed myself with this image. And what an image to get after modifying my own camera - heart in mouth - didn't know whether I would get anything - but it all works really well.

best regards
Paul Mayo

[Brad Moore]

Hi Paul,

Wow, that modded Canon is really sensitive to Ha. I can make out a lot of detail in it, well done.

Maybe a gentle unshapen mask a few times in the bright areas might reveal even more detail.

Cheers,
Brad Moore

[PhotonCollector]

Hello Brad,
Thank you. I take that as quite a compliment coming from an astrophotographer such as yourself.

Your right, the unsharp mask does reveal more detail, but it seems to give the image less "photographic appearance", and stars begin to get a dark shadow around them. I'll have another play with it though and see if I can find a nice balance. But in the meantime, the skies are clear again and I'm getting ready for another night under the stars.

best regards
Paul Mayo

[davidpretorius]

simply awesome

[Brad Moore]

Hi Paul,

Try selecting the stars, invert the selection, expand by 3 pixels, then feather by 2. Then apply your unshapen mask. This way it wont touch your stars.

You can select the stars simply by:

1. Duplicate the background layer.

2. Apply the dust and scratch tool until you blur out all the stars in the the duplicate layer (7-30 pixels should do it).

3. Then select the duplicate layer to "difference".

4. Use the colour range tool with the + set and start clicking on the stars until it gets all of them. Play around with the colour range slider.

5. Save the selection as "Stars" from the Layer menu.

6. Then remove/delete the duplicate layer.

7. If you've lost the selection, just load it back up from the layers menu.

Hope this helps,

Brad Moore