Do's and Dont's of Galxy imaging with a DSLR

[VikN46]

Hi All,

I was wondering if anyone would share there experience of imaging Galaxies with a DSLR and the Do's and Dont's.

I have had some nice images of nebulae (well nice to me and suits my current expectations with my set up).

Is it best to combine a range of exposure time to prevent core burn out or lots of the same length?

My latest galaxy image of M81 had been by far the best compared to my first attempts but I find even though I add darks bias and flat frames it can look noisy, maybe my flats need work or my very basic processing skills .

Anyway here is my latest attempt. Any tips, tricks advice appreciated so I can start Project Galaxy!

M81:

1.1 m81 jpeg colour by VikN46, on Flickr

And M81 crop:

1.1 m81 crop by VikN46, on Flickr

and just for comparison my first go in February this year:

cropped m8110.03.14 by VikN46, on Flickr

Thanks in advance

[VikN46]

Sorry I forgot to add image data

Taken using my usual stuff:
SW 150 PDS, EQ5 Pro Synscan GOTO.
Guiding: SW ST80 and QHY5.
Modded Canon 600D and coma corrector with CLS clip filter.

Using: BYEOS, PHD, DSS, Photoshop CC.

15 x 300s Lights (15 ISO 400 and 15 ISO 800)
10 x 300s Darks
flats and bias

 

[ollypenrice]

In my experience (which is CCD) burn out has far more to do with how you stretch than with how you capture. I routinely use 30 minute luminance subs on galaxies. The linear image tells you how much core data you have. The trick in stretching (and multiple layered stretches work for me) is to stretch everything but the core...

So, in a nutshell, I think it is mostly down to processing.

Olly

[VikN46]

Thanks Olly,

I did think it could be down to my processing I can be a little heavy handed .

[Lee_P]

I'd also be interested to hear experienced imagers' tips for galaxy imaging with DSLRs. For what it's worth, here's my own attempt at M81 and M82:

60 x 60 second, ISO 800. 15 Flat, 15 Dark, 15 Bias.

[Leveye]

You are off to a great start. Use levels and curves to set high and low points and play with the mids to "stretch" the image and coax details out while not blowing out the highs. Layer masking different exposures is really the way to go here. That way you can just tweek the layers and hence just the highs,mids or lows in the entire image without adjusting anything else. Hint. There is tons of detail in the mids. Try playing with those.

[Lee_P]

Whenever I boost the mids it brings out lots of noise. Any tips?

[Notty]

I think once you get to the stage you're getting noise then it means you need more data i.e you've reached the limit of what you can extract from it. To get more you'd need more/longer subs.