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06-05-2016, 02:52 AM   #16
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QuoteOriginally posted by Bewatek Quote
Yes the K50 is excellent but thats not what its about. Full frame or a different camera with even lower noise than the K50 or even a camera with no noise at all would not help because all consumer cameras have an IR/IF filter that cuts out the non-visible or even some visible wavelengths. If you put in a lot of effort you maybe will get a faint purple glow from most nebulae.
Removing or replacing these filters is the key to nebulae photography.
Another problem will be long exposure noise. Even the K50 will become extremely noisy in a 600seconds exposure without active sensor cooling.


Been down the same road. Unfortunately a telescope only makes it much worse for a beginner. Telescopes start at 400mm f5, many cheaper models are even 700mm f10 and above, good luck tracking those focal lengths for the needed exposure times. Just for an orientation i spend 1500$ and a lot of learning and DIY to track 200mm for 600 seconds with confidence.
Attaching a h-alpha filter for example means stacking filters. It helps by cutting out all non-nebulae wavelengths like light pollution but again the exposure times will get ridiculous. Its just a guess but the ~ 90minutes total i need with the filter removed at f2.8 for some decent exposure would expand to... i dont know, two days? Those filters are for filterless cameras only and help getting rid of light pollution or are used with monochrome cameras which are the way to go if you can afford it.

I really would like to encourage you to engage yourself in astrophotography but the no.1 lesson i learnt over the years is to start small and not to have hubble-like expectations. Astrophotography is a complex matter and nebulae are the most difficult targets.
Oh but i almost forgot - the Orion nebulae emits some visible light, you wont be able to see it in all its glory but its possible with a non-modded camera. If you manage to get an image of it with your K50 and lenses and have some fun or satisfaction doing it you can get deeper into the hobby.

I attached a picture of the California nebulae. Its far from perfect but its the result of years of learning and a my-girlfriend-would-kill-me-if-she-knew amount of money.
The California nebulae is probably the easiest, its big, its bright and it has low dynamic range, nontheless it took 3 hours of work outdoors and another 3 hours postprocessing
Its made of approx. 50 exposures total, 16x600seconds at f3.0 actual light exposures, 5x600 exposures for calculating long exposure noise, 16 1/4000s exposures to calculate readout noise and 16 exposures against a flatfield lightfoil for calculating lens errors like vignetting. Its processed with the free software IRIS 5.59.
Camera is DIY, sensor, shutter and processors from a Canon 1100D. Hated it for daylight shooting but unlike Pentax its built like pre-war farming machines which helps modding it. The low megapixel count also helps. The sensor is cooled to 20 degrees C below ambient by a watercooled peltier cooling to keep sensor heating = long exposure noise down. The internal filter is removed, a Astronomik CLS-CCD filter is attached in the lens mount to block light pollution, it helps a lot in spite of me living in the countryside.
The lens is a Canon 200mm 2.8 L ii with a precision focus rig attached. You can say a lot about Canon but they make some decent lenses too. Its also weather sealed.
Mount / tracking is a Sky-Watcher HEQ5 PRO Synscan controlled by SkyMap through a Poseidon POEQ5-USB adapter.
The required autoguiding / tracking controll ist done by an astrolumina ALccd5-II camera attached to a small and bright guiding scope, autoguiding software is PHD guiding.
Of course there are many more small devices and helpers (like a polar finding scope for polar aligning the mount, a two staged optical finder for star-aligning the mount and a lot of heaters (+0,X C above ambient) for the neverending fight against dew.
Long story short: Quick and dirty. It really is, compared to what other people do or what i would like to do.

But again, it all started with a used first Canon rebel / 300D, the kit lens and a cheap tripod

Edit: Michael2012 thats a great image and properly processed, it also shows both the K30/K50s quality and the general improvement in the last years. I could only dream about results like that just with my DSLR.
But the "red stuff" will be hard without modding
Just joined, so this is my first post (Hi!), but I had to comment on one or two points.
Firstly, I started out with Iris - it is very powerful, yes, but horrendous to use! Have you tried Deep Sky Stacker? I find it useful for doing the automation bits like aligning and stacking, and processing the darks, flats and biases.
Secondly, I agree whole heartedly with the 'significant other' complaint!
I like your image - I can't even see the Calif.neb through my LP skies!

---------- Post added 06-05-16 at 03:04 AM ----------

QuoteOriginally posted by Michael2012 Quote
Deep Sky tracker can be daunting when just starting off - There are so many things you can change within the process, and the program can crash a fair bit.
Whilst It does seem to be what a lot of people gravitate to as their free stacking solution, as a beginner who is not much further forward in the learning curve than the OP, I would actually recommend SEQUATOR instead as their stacking program.
It's a lot easier to get to grips with, has fewer actual stacking options, but they are described in layman's terms rather than "techno babble", and it even does a few things that DSS does not ! The lights and darks of the photo in my previous post were stacked using it.


It can be found here:- https://sites.google.com/site/sequatorglobal/


(I have no affiliation to the program or it's creator, just a happy user)


regards,
Michael.
Not tried that one yet, will give it a go.
I usually use DSS - the only real pain is exporting the right TIFF that GIMP is happy with!

06-05-2016, 07:54 AM   #17
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QuoteOriginally posted by JimFR Quote
Just joined, so this is my first post (Hi!), but I had to comment on one or two points.
Firstly, I started out with Iris - it is very powerful, yes, but horrendous to use! Have you tried Deep Sky Stacker? I find it useful for doing the automation bits like aligning and stacking, and processing the darks, flats and biases.
Secondly, I agree whole heartedly with the 'significant other' complaint!
I like your image - I can't even see the Calif.neb through my LP skies![COLOR="Silver"]
Thank you, yes, Iris has a very steep learning curve but its worth the time. I really would not want to work without its dynamic and colour stretching functions:
IRIS TUTORIAL
Check out the other tutorials, not the easiest to understand but worth it.

I tried deep sky stacker and liked it for its interface and time-saving but the results were just not as good as they were with Iris.
06-05-2016, 08:46 AM - 1 Like   #18
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the K-50 & o-gps is a good combo especially widefield.....I got lucky catching comet lovejoy January of '15.....getting the nebula in orion and Andromeda are doable but my editing skills suck so the results kinda suck ....the same goes for widefield milkway for me got great frames but putting it altogether not so good!!
the o-gps is a mysterious device that works well and also can be a frustration......hindsight if I had known about the ioptron skytracker I believe I would have purchased it instead of the o-gps unit as I have seen examples/results of folks using decently long exposures with decently long focal lengths......biggest deal is clear dark skies, free time and post processing
good luck on yer adventure and happy shooting!
06-06-2016, 11:34 AM   #19
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Join Date: Jun 2016
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QuoteOriginally posted by Aaron28 Quote
......biggest deal is clear dark skies, free time and post processing
good luck on yer adventure and happy shooting!
Aint that the truth!

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