Cigar Galaxy Help

[CThody]

Hi. I thook these images last night. Not the best of seeing conditions, but not bad. The first image (cigar.jpg) at 3200ISO 80 sec exposures and 3 darks... The second image (cigar1.jpg) identical except I used an Astronomik light pollution filter.

I would like to know what I could do to improve these or my technique. Using the Astronomik filter cuts out some pollution, but also a lot of data it seems.

Used and EOS 7D with a Celestron C8 on an EQ5 Synscan.

[Bizibilder]

You don't say how many exposures you took? But I would suggest that you take many more - enough to get a total exposure time of at least an hour or two. Similarly you need a lot more darks - around 20-30. Also cut the ISO down to 800 maximum - DSLR's are generally quite noisy above this value.

That light pollution filter certainly seems to work! That's a very nice image - well done.

[ollypenrice]

Yes, you need a lot more signal. More exposures and longer, if possible.

I'm not sure about the filter. There should be a strong red signal in the central part of the galaxy but the LP filter seems to have done for this. But the background sky is better. A case for layering in the best of both worlds, but tricky...

The images are good though, as far as the signal goes. Was this at f10? You will struggle for signal and guiding at that, if so. I would urgently advise the f6.3 reducer.

Olly

[CThody]

Hi. Yes this was a f10. I have the reducer, but I thought that was for widefield views, so thought I would lose detail of the galaxy if I used it. I'll give it a go, thanks for the tip!

The LP Filter does turn everything blue unfortunately, and I can't work out how to get rid of that and restore the correct collours - DSS baffles me really. Want to try a different program to see what effect I get.

[ollypenrice]

Had you had no trailing you would have had more resolution at f10 than at f6.3. However, the trailing has smeared away any benefit. What is more, f10 is has cut your signal to well below half what it would have been at f6.3.

In amateur terms a focal length of around 1.3 metres is absolutely not widefield. I am, at present, over and out at just below a metre.

Olly