M33

[Sparrow]

Taken through the Astrotech 66mm with the Canon 1000D (unmodded).

30 x 5 minute subs at ISO 800. Flats used but no darks.

[Sparrow]

Here's the image

[oldfruit]

Really nice image of a challenging target.

[philj]

Thats nice. A very challenging target well captured, I like the colour. Unmodded cameras work well with galxies but a modded will add just that bit extra from the Ha regions which this galaxy is rich in.

Philj

[Sparrow]

Thanks for that. Yes Phil the Ha is harder to catch with the unmodded camera but I think more longer subs might help me to improve this one. Even with the LP filter I'm often restricted to 5 minutes max exposures because of light glow. If the conditions are right I have been able to go to 15 minute exposures and I long for those nights to get more data.

[MartinB]

Just gave it a few tweaks Sparrow. It's a fine image and your unmodded camera has picked out a couple of ha regions very nicely

[Sparrow]

Thanks Martin. The red channel noise is frustrating with this one but if I process it out, I also lose much of the Ha signal in the galaxy. I'm firmly convinced this problem is from LP form a neighbour's garden light which I have tried to mask with an old blanket and garden canes.

[Sparrow]

This is my second attempt at processing it. I've managed to remove the noise from the sky whilst retaining the Ha signal in the galaxy - much more pleasing than the first version I think.

[MartinB]

A definite improvement

[siovene]

Hi Sparrow, how bad is LP from your site? You said that with a LP filter your single shots will saturate at 5 minutes? Then how long without the filter?

Thanks.

[Sparrow]

I reckon no more than about 30 seconds without a LP filter. I'm in Chester and the LP is really bad - I'm just by the hospital so the lights from there are bad, plus a main raod with high pressure sodiums, and in the distance is a shell oil refinery which lights the sky up. When there's less moisture in the atmosphere I have been able to go up to 15 minute subs, but that's quite rare. Normally, on a good night I can go for 10 minutes max, and as with last weeken, 5 minutes was the max really.

As a comparison, I was in North Cumbria (Near Cockermouth) for a few days a month ago taking 5 minute subs quite happily without a LP filter at all. Sadly there was a full moon so I couldn;t really get any useful data other than a few widefields of the Milky Way.