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  #1  
Old 13-06-2018, 09:15 PM
Gundary5 (Shane)
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Trifid & Lagoon

Hi guys,
Thanks for the excellent advice so far. Iíve downloaded Deep Sky Stacker and given it a go. I think Iíve dialed in my polar alignment pretty well. Looking forward to a permanent setup.
10 frames, each of 1 minute at ISO 800. To get more depth of colour, will more exposures do it? Or is there no substitute for longer exposures?
Also, while Deep Sky Stacker was very easy to use, should I be tweaking anything or are the default settings good enough to get me going?
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  #2  
Old 14-06-2018, 12:30 AM
kosborn (Kevin)
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Very nice. More data is better... You don't have much noise in the background so you might be able to tweak the saturation and curves to bring out the nebula a bit more. With so little noise you could also trying increasing ISO to 1600. The stars are looking a little bit elongated so increasing exposure time might not be best. Keep at it though - it's looking good!


Kevin
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  #3  
Old 14-06-2018, 08:46 AM
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PKay (Peter)
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Way better.
Well done

Minimum of 30 subs works for me.
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  #4  
Old 14-06-2018, 10:50 AM
Gundary5 (Shane)
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Thanks for the tips. My next question is, is it possible to automate the imaging process? Like an app that I can just tell to take 50 images at 2 minutes on my Canon?
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  #5  
Old 14-06-2018, 11:05 AM
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both more sub and longer can help, but I think your bottleneck here is processing rather than data. your image looks nice and clean and I feel the nebolsity can be brought out further from the darkness. I dont know if DSS has fine enough controls for that, but i suspect it does for the patient. Longer subs will naturally give you brighter nebulosity while more subs will give you better signal to noise ratio to allow more agressive stretching. The nebulosity is there already though. Look at your individual subs though and check the lagoon isn't overexposing. looking at your jpg there is much more lagoon already there in the image waiting for you to tease it out.

This is where you start learning to use masks to allow you to stretch only parts of the data not the whole image. Aligning and stacking alone doesnt give you that great image unless you are lucky. Adjusting levels wont either. You need to adjust various parts of the histogram where the signal is lurking and just stretch that bit forward. Then repeat for another area and slowly you build it all up. Curves may be a good place to start experimenting too.

The DSS default settings are good to get you started but not always an ideal place to start. When you have time reprocess and carefully check EVERY option available, read what it does and decide what to use. Always choose the best slowest option if in doubt, it gives you a cleaner more accuratelty aligned final image with less artifacts introduced, so when you start stretching you have better signal and less noise to work with. Ignore if it takes overnight to run , it often does in astrophotography, there is no one click solution really. DSS is the Fischer Price of AP programs, yet it does have strong features that plenty of people master to get magnificent pictures from it. But they all take effort from the user to make it happen.

Even the commercial packages need the user to work at it to get good images. You may want to consider AstroPixelProcessor. Its not far off a one click package but has tons of power when you need it and the default settings work superbly. I think its a good affordable step up from DSS if you're not yet keen to go to something like PixInsight (my package of choice, but there are other high end quality packages others here prefer). APP's defaults and autostretch give a damn good image ready to save as jpeg, tell you what if you want to email your 10 subs for this image to me at sjbolton at gmail dot com I'll chuck them through AstroPixelProcessor and post the result. I'm betting the nebulae will be brighter by default and wider. And it'll give you an idea of what your data has and if its worth considering buying some better software than DSS.

Or it could come out worse or the same. But I doubt it. I'll just see what the defaults do on their own.


One other point i think you may be a tad out of focus (a constant struggle for us all).
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  #6  
Old 14-06-2018, 12:01 PM
Gundary5 (Shane)
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Thanks Sil, that’s very informative! I agree it’s out of focus. Very hard to do through a DSLR on only an 80mm. I just made a Bhatunov mask to see if that helps. Let me see if I still have the originals. They are Canon RAW files, I assume that’s ok for high end software?

Edit: the files are too large to email!
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  #7  
Old 14-06-2018, 02:25 PM
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Yes generally Canon and Nikon RAWs are supported on all packages.

Too large? tell you what, can you convert the lights to TIFF 16bit files and see how they turn out size wise for email. one image per mail? no need for darks or flats either, hell you can probably halve the dimensions too or even send as jpegs but then it become a poor comparison. If you have an online storage location you can upload just send me download links. You can pretty much work with any digital camera files for astrophotography and get good results. But to get a good comparison for you the closer to the source without altering in any way the more meaningfull the comparison should be. No stress, communicate with me via email as i wont see the forum until next week, its Le Mans this weekend and I'm hibernating but should be able to work on them tonight or tomorrow anyway. My Nikon i think is 56MP so dimension shouldnt be a problem to work with, but also may be hard to reduce filesize because so many pixels. If you have to convert the raw choose Daylight whitebalance option, that seems to give good star colours.
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  #8  
Old 14-06-2018, 02:33 PM
Imme (Jon)
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Quote:
Originally Posted by Gundary5 View Post
Thanks Sil, thatís very informative! I agree itís out of focus. Very hard to do through a DSLR on only an 80mm. I just made a Bhatunov mask to see if that helps. Let me see if I still have the originals. They are Canon RAW files, I assume thatís ok for high end software?

Edit: the files are too large to email!
Bahtinov mask is a great move.

I've recently moved to using them and much prefer that over even FWHW computer aided focusing. I haven't actually put the autofocuser on the new scope yet and don't think I will!
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  #9  
Old 14-06-2018, 02:37 PM
raymo
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Your signature does not list your camera make/model; does your DSLR have LiveView, if so magnify the LCD screen 5x, that will make focusing much easier. Using the viewfinder is a waste of time. Focus is the single most
important aspect of AP. If no LiveView, get a Bahtinov mask, cheap, and
makes focusing a snap.

Yes, Sil, you can achieve quite a lot using DSS, all my images are
completed there, apart from a bit of sharpening if required. The RGB
sliders particularly are very touchy though.
raymo
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  #10  
Old 14-06-2018, 03:02 PM
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PKay (Peter)
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Backyard EOS

Automates the image taking process and has focus tools.

Need a laptop as well.
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  #11  
Old 14-06-2018, 03:34 PM
raymo
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Cheaper alternative, if that is of importance, get an intervalometer from
ebay, about $20. No laptop needed, and simple to use.
raymo

Last edited by raymo; 14-06-2018 at 03:36 PM. Reason: more text
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  #12  
Old 14-06-2018, 09:08 PM
Gundary5 (Shane)
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Quote:
Originally Posted by PKay View Post
Backyard EOS

Automates the image taking process and has focus tools.

Need a laptop as well.
Thanks Peter,
This is perfect! It’s out running now. As far as I can see there’s no PC interface for the 7D so I’ve hooked up the 5D. The focus aid is sensational.
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  #13  
Old 14-06-2018, 09:15 PM
raymo
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Thanks for acknowledging my suggestions.
raymo
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  #14  
Old 21-06-2018, 02:07 PM
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Quote:
Originally Posted by raymo View Post
Cheaper alternative, if that is of importance, get an intervalometer from
ebay, about $20. No laptop needed, and simple to use.
raymo
Intervalometer essential. do your shooting anywhere, any time, as raymo said, no laptop needed.

Especially when you realise you basically only have one set of camera settings for most of your shooting and if you're using cheap memory cards you have saving lag to contend with but once you hve the optimal settings you basically stick with them and you just put them in your intervalometer and lock the shutter and off it goes.
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