To the stars


K10D

Link Posted 22/01/2015 - 01:06
I'm about to start photographing stars. Since it gets very dark in WA with clear skies, we have area's nearby with zero light pollution. So Iíve been reading up on techniques and kit.

I have just ordered an Astrotrac TT320X-AG and a PS-10 Polar scope. link

I know that the O-GPS1 GPS also has an astrotracer function so am picking one up this Saturday.

So it's an all out assault to try and get some decent images.

If anyone already does this stuff, please post images or put up some pointers on how to keep it simple and get reasonable results.

Best regards

JForeigner

Link Posted 22/01/2015 - 11:55
Hi Gary,

It depends what you are trying to get images of. The night sky covers a lot. I started down this path about 9 months ago, and have really enjoyed it, as well as finding it very frustrating at times. But I am still learning.

So here I go.

I would recommend something like a planisphere to find what you are looking in the sky, and what time of the year different stars are in view. A dark sky really helps, light pollution, or a full moon can work against you. I started by building a barn door tracker to overcome star tails, but I did not get on with it. My next step was to buy a Skywatcher Star Adventurer. Fantastic idea, but this where I am having my main problem. I am struggling to polar align the mount. In the southern hemisphere, there is not a convenient star to help you, such as Polaris. This mount uses the constellation Octans to help you polar align south of the equator. This should be easier for you, but here in Darwin, being close to the equator, this constellation is next to impossible to find, as it is so low in the sky. Well, so far each time I have looked for it.

So my next step was to buy a o-gps. It arrived on Monday, and yes, it works. This time of the year, monsoon season time is not the best time to try it out, but I have had a play with it. It is a bit of a mystery sort of device. It is not happy shooting straight up, but at a reason angle, it worked well. I was able to capture the Lovejoy comet a couple of nights ago in the gaps in the clouds. I need to play with it more. It does some things I can't explain. I can get a longer timed shot with my 200mm, than what I can pointing in the same direction on the same night with my 50mm. I have no idea why.

Gear wise, I have not brought any new lenses, yet. I have just used my 16-50, FA 50 1.4, and a Tamron 80-200 f2.8. The two zooms I prefer, over the prime. Wide open, the 50mm is not so nice. Try different lenses. Find which ones work best for you. Focus using live view, the view finder is just too hard to get correct focus. Also check your focus from time to time. I have for a "to see what happens" sort of thing, just put my Q on the back of the Tamron via an adaptor. I have pointed it at a blood moon, as well as the Orion nebula. I was pleasantly surprised.

I can't offer much advice on processing images. I have Elements version 12, but I am not sure if this is what I really need, or what is best.

My aim for this year, is to do a panorama of the milky way, I done one last year, but it is not anywhere near as good as what I am aiming for. It is riddled with mistakes, but it was a good starting point.

I am sure there are others with information, but that is my 2 cents worth.

Regards

Gary



Armed with a K3, some M, A, FA, DA, and star lens. With an eye open for "just one more lens".

My PPG link

Gwyn

Link Posted 22/01/2015 - 12:40
I have an O-GPS1, and I bought a Samyang 14mm for my California trip.
It was all very hit and miss there, getting used to the astro-tracer function, working out exposure times, and trying to keep an impatient His Nibs happy too (he wanted to try it all out with his camera too and ended up using it for longer than I did ).

Anyway I ended up with a couple of photos I liked. I just wish I had dark skies here to play about more. I am hoping we will get to La Palma sometime so I can play again. Can't see me getting back to Death Valley or Yosemite any time soon.



An attempt at the milky way from Death Valley



Sky from our motel outside Yosemite

I keep hoping for clear skies to see Lovejoy, but no luck yet. Last night was fairly clear, but I didn't have the car to get out away from the worst of the light pollution .

There are several apps, which are useful for astrophotography, and lots of tutorials on the web of course. Deep Sky Stacker is an essential bit of software too.

Have fun. Main advice - don't take anyone with you who wants to borrow your gear .

K10D

Link Posted 22/01/2015 - 13:02
Great images there from both Gary and Gwyn! No pressure then.....

Many many thanks for the input. Alignment is the biggest issue that I consider being a problem to get some decent images. Apparently I have to find the South Celestial Pole starting with the Southern Cross and using an intersect from The Pointers.

Saturday night should be my first attempt once I get the GPS1 set up. I've been told to have a head torch (LED) and a basic compass?

If I don't post sometime next week, I'm lost in the outback!

Best regards

LennyBloke

Link Posted 22/01/2015 - 13:31
Good luck with your adventures - I predict it will a long, frustrating, but ultimately satisfying journey for you

You'll probably need to do quite a bit of experimentation with different lenses and their apertures. You'll have gathered from your research that the bigger the aperture the more detail you can potentially capture, but you'll also find that there are very few "fast" lenses that will deliver top results without having to stop them down a little (some lenses need just a stop, others more).
Personally I find primes much better than zooms, but each to his own

Coma is an aberration that can be particularly distracting and is present on many lenses at wider apertures - it creates a wing-like appearance to stars the closer you are to the edge of the frame and I don't know of any tools that can correct it.

Accessories are very important! spare batteries (the O-GPS1 can gobble them up in cold conditions). A cable release (using the mirror-up 2 second timer works best for me) is vital. A sturdy tripod with a good "shoulder height" (you don't want to extend the centre column too much) to avoid vibration. Flask, gloves, rum, etc at certain times
LennyBloke

Gwyn

Link Posted 22/01/2015 - 14:20
A head torch is an excellent addition, try to find one which has a red filter option as well, so you don't ruin your night vision.
I use my little Pentax remote and the 2sec timer. I also used live view, about the only time I have,incidentally.

The Samyang suffers from coma, but it is a good beginners lens I think.

JForeigner

Link Posted 23/01/2015 - 12:16
I heard that Perth had it's hottest day on record, so I guess that a flask and gloves may not be required. I may add rum to my list. A compass is a good idea, I use it to help me polar align. But here is my first nights attempt with my o-gps1. FA50mm 1.4, stopped down a couple of stops. Comet Lovejoy, with the Pleiades. Also with monsoon clouds and light pollution thrown in. Since then, all we have had is clouds, and more clouds. Not the greatest of pictures, but taken from my front yard, to show what this little unit can do.

Gary



Armed with a K3, some M, A, FA, DA, and star lens. With an eye open for "just one more lens".

My PPG link

Gwyn

Link Posted 23/01/2015 - 12:42
I like the photo. I'm glad someone has managed to get Lovejoy! It was clear again last night, but I couldn't raise the enthusiasm to go out in -8C to take pictures.

The O-GPS1 offers a compass and simple navigation, but an ordinary compass is probably easier to use.

Darkmunk

Link Posted 23/01/2015 - 14:52
I just pointed the Zed and 35mm @f4 in the general direction and fired off a few under-exposed shots (to keep the shutter speed up, as I don't have any kind of tracker).
After getting home and zooming in I discovered the little green blighter on one frame
It was midnight and the comet was nearing the pollution of Plymouth, but it looks quite funky anyway I think
click on it



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Last Edited by Darkmunk on 23/01/2015 - 14:54

K10D

Link Posted 23/01/2015 - 16:06
The dealer does not have the GPS 1 in stock! So I have one coming from Japan. That said, tomorrow nights outing is cancelled. The Astrotrac is in Singapore so I should have that by Wednesday as Monday is a national holiday here - Australia Day.

Having seen the above image from Mark, I thought I'd just fire a couple off from the garden. Both with 150mm f/2.8

There's a meteor streak in the second image!







Best regards

Gwyn

Link Posted 23/01/2015 - 16:16
Happy Australia Day for Monday!

I wish I had skies that dark from my back garden.

Darkmunk

Link Posted 23/01/2015 - 16:19
Cool! So did this have a tracker of any sort. If not, what settings did you use?
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K10D

Link Posted 23/01/2015 - 23:43
Thanks Gwyn. Street lighting here is minimal and you very rarely see house lights on at night? I'm based well south of Perth, just short of the "sticks".

No tracking used Mark. First image was one second at f/2.8 ISO 12800.

Second image was eight seconds at f/5.6 ISO 12800.

The full res images show that the focus is just off on both images.

Best regards

JForeigner

Link Posted 24/01/2015 - 03:46
In time I will learn to process this type of image, so the stars are brought more. But this image was taken on a static tripod. Uluru (Ayers Rock), lower right hand corner, with Orion in the top left.

Regards

Gary



Armed with a K3, some M, A, FA, DA, and star lens. With an eye open for "just one more lens".

My PPG link

K10D

Link Posted 24/01/2015 - 05:35
A great image Gary, I hope you don't mind me tweaking it a little.




Best regards
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