New to Astrophotography - Feedback and Advise

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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Pally86
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Joined: Sat Jan 16, 2016 10:07 pm

New to Astrophotography - Feedback and Advise

Post by Pally86 »

Hi all,

I have recently taken up astrophotography as a hobby and have managed to produce my first couple of images using DSS and StarTools. I was hoping that someone could take a look for me and give me some advise as on how to improve my images? They're certainly not spectacular, but for my first and second attempts I'm satisfied with them.

First I shot the Orion Nebula, 1 min per image at ISO 1600, totaling 45 mins I think. I used lights, darks, flats and bias frames for this one. It was a little cloudy and I'm on the edge of a city so light pollution is a problem but I'm willing to put up with it while I find my feet. I'm only a 10 minute drive from much darker skies!
https://www.flickr.com/photos/139390519 ... res/55Tj02

Second I tried the Andromeda Galaxy, although it was clear, the moon was full and there was a lot of moisture in the air so seeing was rather poor. But i decided that I'd be better of trying and maybe learning something, than not trying at all. 2 mins per image at ISO 400, about 100mins I think. I maybe under exposed this a little... Lights, darks and flats only for this, I read somewhere that the bias noise is in the darks??
https://www.flickr.com/photos/139390519 ... res/9q90h1

Original data for both should be here:https://www.dropbox.com/sh/y28ty7kuahh4 ... kDGZa?dl=0

Any comments, advise, attempts to process would be very welcome!

Also, has anyone used an astronomik CLS LP filter for Canon DSLRs? Considering getting one if it will improve things.

Thanks all,
Dave
Last edited by Pally86 on Mon Jan 25, 2016 10:28 am, edited 2 times in total.
Burly
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Re: New to Astrophotography - Feedback and Advise

Post by Burly »

Hi had a go im no expert but heres my effort needed to crop a bit,maybe colour needs tweaking a bit more,bit blue on stars .
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24483315901_0ab4c9df95_z.jpg
24483315901_0ab4c9df95_z.jpg (43.99 KiB) Viewed 5696 times
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Re: New to Astrophotography - Feedback and Advise

Post by admin »

Hi,

Welcome to the hobby and the StarTools forum!
Pally86 wrote:Hi all,

I have recently taken up astrophotography as a hobby and have managed to produce my first couple of images using DSS and StarTools. I was hoping that someone could take a look for me and give me some advise as on how to improve my images? They're certainly not spectacular, but for my first and second attempts I'm satisfied with them.
Your data looks pretty darn good for a 1st attempt - it's a very good start indeed!
First I shot the Orion Nebula, 1 min per image at ISO 1600, totaling 45 mins I think. I used lights, darks, flats and bias frames for this one. It was a little cloudy and I'm on the edge of a city so light pollution is a problem but I'm willing to put up with it while I find my feet. I'm only a 10 minute drive from much darker skies!
Image
Darker skies will help immensely with acquiring signal on the fainter objects (e.g. galaxies), so if they're only 10 minutes away it would definitely be worth it once you're ready to tackle those.
Second I tried the Andromeda Galaxy, although it was clear, the moon was full and there was a lot of moisture in the air so seeing was rather poor. But i decided that I'd be better of trying and maybe learning something, than not trying at all. 2 mins per image at ISO 400, about 100mins I think. I maybe under exposed this a little... Lights, darks and flats only for this, I read somewhere that the bias noise is in the darks??
Image
Much depends on your camera and what its native ISO is. Later Canons sit around 800 or 1600, so it is advisable to use that setting if appropriate.
Any comments, advise, attempts to process would be very welcome!
I had a very quick stab at your M42 data to prove the following point; as you mention, the seeing probably wasn't the best. In those cases you'll find your data is oversampled. You may want to consider binning your data in that case, so you can turn the 'uesless' resolution into noise reduction. See that fine noise in your Flickr image? It's much finer than the actual detail - that's what I'm talking about. Getting rid of that noise then allows you to perform things like deconvolution which can help reverse some of the seeing related blur and reveal more detail;
Orion Neb with Flats.jpg
Orion Neb with Flats.jpg (107.8 KiB) Viewed 5684 times
See how this image may be reduced in resolution, but actually shows a little more detail?
Also, has anyone used an astronomik CLS LP filter for Canon DSLRs? Considering getting one if it will improve things.
There are many people using Astronomik Or LDAS clip-in filters. One thing that is true for all filters is that they will irreparably damage your colors (since you're rejecting parts of the spectrum), notably any yellow colors. It totally depends on whether you think that is a problem. There are ways to get around that with a bit of extra effort though (see here).

Hope this helps,
Ivo Jager
StarTools creator and astronomy enthusiast
LanFeusT
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Re: New to Astrophotography - Feedback and Advise

Post by LanFeusT »

Hey Ivo,

In terms of using a DSLR would you shoot luminance with the filter but in B/W only then color without the filter?

As for the process, they would be processed separately, but how do you combine them, having to remove the filter would probably mess up the alignment as well, so we'd have to align both stack separately?
Bill55
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Re: New to Astrophotography - Feedback and Advise

Post by Bill55 »

I've been thinking about trying this as well. I use Astrotortilla to align with my target. I have successfully used it to re-centre after a software glitch that stopped tracking. Getting back to the same place after a filter change shouldn't be a problem. Might not be spot on pixel wise, but its very close.
LanFeusT
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Re: New to Astrophotography - Feedback and Advise

Post by LanFeusT »

I mean I would have no problem being roughly aligned, during exposures I dither a lot and so each exposure is never right on the same spot as the previous one, and then you stack each of the individually.

But how do you align both stacked exposures together?
Pally86
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Re: New to Astrophotography - Feedback and Advise

Post by Pally86 »

Thanks for the responses all, it's useful to see what others are capable of doing with the same data using StarTools. I'll have to take a closer look at binning and have another go at processing them both.

For my Andromeda Galaxy image, is vignetting the reason that there seems to be less of the galaxy visible around the edges? Or is it how I have used Wipe? I didn't mask the area of interest for this one like I did the Orion Nebular as when I tried it seemed to leave an unnatural looking bright blob surrounding the galaxy. I will try re-imaging Andromeda at some point using a long lens rather than my telescope as I think it fills the frame too much.

As it my be useful, I am using a Skywatcher Explorer 200P on a motorised EQ5 mount. My camera is a Canon 1000D DSLR.

Thanks again,
Dave
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Re: New to Astrophotography - Feedback and Advise

Post by admin »

LanFeusT wrote:Hey Ivo,

In terms of using a DSLR would you shoot luminance with the filter but in B/W only then color without the filter?

As for the process, they would be processed separately, but how do you combine them, having to remove the filter would probably mess up the alignment as well, so we'd have to align both stack separately?
Simply shoot two color stacks and stack/process them as you normally would. In DSS or some other stacker you should be able to align the stack to an external reference image (which won't get stacked). This way you should be able to align both stacks.

When shooting the color stack, you need less data, as detail/noise isn't that important - also just lightly process this stack; no need to tease out detail much.

Combining can be done this way for example.
Ivo Jager
StarTools creator and astronomy enthusiast
LanFeusT
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Joined: Mon Jan 19, 2015 6:29 am

Re: New to Astrophotography - Feedback and Advise

Post by LanFeusT »

admin wrote:Simply shoot two color stacks and stack/process them as you normally would. In DSS or some other stacker you should be able to align the stack to an external reference image (which won't get stacked). This way you should be able to align both stacks.
Did not know that! Thanks, I'll double check it tonight, you rock!
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