Night Sky Photography
Posted 28/04/2009 - 19:55
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I have not a lot of experience with that. Bob (a.k.a. RR) had sent me this link recently, which is more like how to take star trail photos.
From that and Malo's fine star trail example in the competition here, I think you'll get problems in avoiding star trails. At 70 mm and 10 seconds I already saw lines where the stars should have been. (This was pointing more or less due West, though). If it is anything like a dark night (which you need to see the stars in the first place) I suppose you would need a much longer exposure than 10 seconds.
I think the best advice is: Go out, have a play and enjoy it. The worst that can happen is that you learn a lot without getting a reasonable shot.
For proper galaxy photos I know that you need a clockwork (or computer controlled drive) to keep the stars in the same place in your frame. That is a different ballgame alltogether...
Hope it helps,
Prieni
Good light tonight!
From that and Malo's fine star trail example in the competition here, I think you'll get problems in avoiding star trails. At 70 mm and 10 seconds I already saw lines where the stars should have been. (This was pointing more or less due West, though). If it is anything like a dark night (which you need to see the stars in the first place) I suppose you would need a much longer exposure than 10 seconds.
I think the best advice is: Go out, have a play and enjoy it. The worst that can happen is that you learn a lot without getting a reasonable shot.
For proper galaxy photos I know that you need a clockwork (or computer controlled drive) to keep the stars in the same place in your frame. That is a different ballgame alltogether...
Hope it helps,
Prieni
Good light tonight!
How inappropriate to call this planet earth when it is quite clearly Ocean. - Arthur C. Clarke
Prieni's PPG page
Prieni's PPG page
Posted 29/04/2009 - 10:16
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Thanks for the advice.
Didn't have much success really. At least I know two things now - light pollution causes a lot of problems, and a telephoto lens isn't right for the kind of shots that I wanted to take.
Couple of plus points though, ISO 400 and a 10 second exposure on the f5.6 seemed to work with a little smearing. That should mean my f1.4 50mm should get very close to the images I'm looking for. Think I'll check ebay for some fast lenses, old ones should be cheaper and I'm not fussed about auto focus...
Didn't have much success really. At least I know two things now - light pollution causes a lot of problems, and a telephoto lens isn't right for the kind of shots that I wanted to take.
Couple of plus points though, ISO 400 and a 10 second exposure on the f5.6 seemed to work with a little smearing. That should mean my f1.4 50mm should get very close to the images I'm looking for. Think I'll check ebay for some fast lenses, old ones should be cheaper and I'm not fussed about auto focus...
k5, 50mm FA, 18-55mm Kit, 50-200mm DA, 15mm Fisheye Sigma, 10-17mm DA Fisheye, 18-55mm DA WR, DA* 60-250, DA* 16-50
Posted 29/04/2009 - 16:50
Link
I've done a bit of this, and am sort-of planning to do more
10 seconds at 50mm is the longest you can realistically get away with. If you practically-minded, you might be
better off making one of these - prob. cheaper and better than a fast lens.
They come in various forms - from the basic 'two-bits-of-wood' up to
computer controlled fancy versions. Googling 'barndoor tracker' or 'scotch mount' gets you a lot of info - and
some is collected here.
Minimally all you need is a couple of bits of wood, a hinge, a bolt and nut, some way of fixing it to your tripod and something (ball head?) to attach the camera to. You can align it well enough for wide-angle photography (50mm is def. wide angle in astrophotography) by just sighting along the hinge to the pole star.
On noise reduction, the usual thing to do is turn it off (problem for K20d users) and take multiple exposures, along with a few manual 'dark' frames, and then stack the result. Applications (free) for this include Registax and Lynkeos (mac). Serious astrophotography also uses other types of frame (here for example). You then need to post process a fair bit.
For really good results, an Astrotrac is supposed to be very good - just eye-wateringly expensive.
Good luck,
Neal
10 seconds at 50mm is the longest you can realistically get away with. If you practically-minded, you might be
better off making one of these - prob. cheaper and better than a fast lens.
They come in various forms - from the basic 'two-bits-of-wood' up to
computer controlled fancy versions. Googling 'barndoor tracker' or 'scotch mount' gets you a lot of info - and
some is collected here.
Minimally all you need is a couple of bits of wood, a hinge, a bolt and nut, some way of fixing it to your tripod and something (ball head?) to attach the camera to. You can align it well enough for wide-angle photography (50mm is def. wide angle in astrophotography) by just sighting along the hinge to the pole star.
On noise reduction, the usual thing to do is turn it off (problem for K20d users) and take multiple exposures, along with a few manual 'dark' frames, and then stack the result. Applications (free) for this include Registax and Lynkeos (mac). Serious astrophotography also uses other types of frame (here for example). You then need to post process a fair bit.
For really good results, an Astrotrac is supposed to be very good - just eye-wateringly expensive.
Good luck,
Neal
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185 posts
17 years
London,
UK
What I'd like to achieve is a good snapshot of the sky, without star trails, initially.
From what I've read, ISO 200 is a good place to start - along with switching off the autofocus and setting the lens to infinity. I'm guessing that the apperture / shutter speed combination is going to dictate the sharpness of the image. Does anyone have some example settings that are likely to work well together?
In terms of equipment, I'll be using a telephoto f5.6 lens (my 70-300 Tamron) as I need to shoot through a fairly narrow opening. Also, I'll be using my k200d so I don't think there's an option to raise the mirror prior to taking the exposure. I do have the long exposure noise reduction setting enabled though.
Equipment wise, I've also got a sturdy tripod and cable release. I'm not expecting to get stunning results, but I was interested in any tips that might bump me up the learning curve a little quicker.