Night time photos - sky / stars

[james_tigerwoods]

I've just been out on my patio trying to take some sky / star photos but it was a spectacular failure as I couldn't focus on anything (using the 18-55 or the 55-200VR) and even in manual, I couldn't see a damn thing, let alone focus on anything at all.

So, my question is how do I take starry sky photos?

[D4VE 3LL]

You could either set it up just as its getting dark and try some high ISO settings and get it in focus then put it into manual focusing and leave it. Are you going to do X amount of 30 sec exposures? This way you'll avoid hot pixels, some light pollution and noise. Another tip is try and look for the North Star i think it is or one of them. Every other star circles around it which looks pretty cool.

[Stu R]

Focussing on Polaris can certainly yield some funky looking shots

http://www.wikihow.com/Photograph-the-Night-Sky

I used that as a guide, got some decent results recently but I'm more interested in shooting through my telescope now.

[D4VE 3LL]

Stu R said:

...Polaris...

Thats the one!

[james_tigerwoods]

D4VE 3LL said:

You could either set it up just as its getting dark and try some high ISO settings and get it in focus then put it into manual focusing and leave it. Are you going to do X amount of 30 sec exposures? This way you'll avoid hot pixels, some light pollution and noise. Another tip is try and look for the North Star i think it is or one of them. Every other star circles around it which looks pretty cool.

Yes, 30second exposures was what I was going to try - not tipping the camera over was also something I was trying to avoid...

[cottonfoo]

I zoom in on one bright star, get the best manual focus I can, then zoom back out and take some test shots. Having an old camera means I can't zoom in on any 'live view' or whatever. Is really good fun though.

http://www.flickr.com/photos/cottonfoo/3544276146/
http://www.flickr.com/photos/cottonfoo/3544277712/
http://www.flickr.com/photos/cottonfoo/3480700541/

[james_tigerwoods]

cottonfoo said:

I zoom in on one bright star, get the best manual focus I can, then zoom back out and take some test shots. Having an old camera means I can't zoom in on any 'live view' or whatever. Is really good fun though.

http://www.flickr.com/photos/cottonfoo/3544276146/
http://www.flickr.com/photos/cottonfoo/3544277712/
http://www.flickr.com/photos/cottonfoo/3480700541/

Thanks

I do rather like this:



How did you manage that?

Edited by james_tigerwoods on Wednesday 16th September 12:31

[cottonfoo]

Facing the other way toward Mt Cook Village, Southern Cross at the top. These were taken around 12.30-1am.

http://www.flickr.com/photos/cottonfoo/3480642585/

Wonky test shot, but I like the clouds:

http://www.flickr.com/photos/cottonfoo/3464264688/

Not bad for a D50 really.

[cottonfoo]

james_tigerwoods said:

How did you manage that?

30 odd seconds ISO1600 I think, can't remember the aperture off hand (NEF's are at home), tripod (Gorillapod in this case) and IR remote.

[james_tigerwoods]

cottonfoo said:

Facing the other way toward Mt Cook Village, Southern Cross at the top. These were taken around 12.30-1am.

http://www.flickr.com/photos/cottonfoo/3480642585/

Wonky test shot, but I like the clouds:

http://www.flickr.com/photos/cottonfoo/3464264688/

Not bad for a D50 really.

Nice. Very nice

[bramley]

I'm off to Devon soon and would like to do some star shots. Last time I tried I ended up with little more than hot pixels and noise. How do I get round that?

Ta

[D4VE 3LL]

bramley said:

I'm off to Devon soon and would like to do some star shots. Last time I tried I ended up with little more than hot pixels and noise. How do I get round that?

Ta

Do them in 30sec exposures (it'll take over an hour depending how much you want) then stack them. IIRC there are specialist programs for "star trails".

[cottonfoo]

Best thing is to practice. You can do it at home before you go but better to do that somewhere with a similar level of light pollution as to where you'll be going.

Try a wide lens at ISO 800, f3.5 for 30 seconds at first and adjust as neccessary.

[don4l]

bramley said:

I'm off to Devon soon and would like to do some star shots. Last time I tried I ended up with little more than hot pixels and noise. How do I get round that?

Ta

What camera and lens are you using?

Basically, you want to set up the camera on a decent tripod. Then you need to connect up a laptop and take several images while focussing. During focussing, use the highest ISO setting and widest aperture and medium image quality. 10 second exposures should be fine for focussing.

Once you are happy with focus, reduce the ISO to 800 or even 400. Step the aperture down one step, set the exposure to 30 seconds and image quality to highest. If you want star trails, then set the exposure as long as you can.


There are two ways to deal with the hot pixels.
1) Dark frame subtraction
2) Noise rejection techniques.

For the moment I would recommend the first method. Take some shots with the lens cover on. These shots must be taken at the same iso and exposure settings as the proper photos. Take at least 7 darks.
These darks need to be "averaged" to produce a master Dark which you subtract from each of your lights. There is a free software package called "Deepskystacker" which you can do this with.

Finally, before you go to Devon, check what the moonrise and moonset times. Don't bother if there is more than a quarter moon in the sky.



Don
--

[cottonfoo]

I'd try both with and without noise reduction and see what looks best. I turned it off since some small points of light look a bit like noise and are cancelled out.

Some cameras work better at astro than others due to them not having such strong IR filters.

[don4l]

cottonfoo said:

I'd try both with and without noise reduction and see what looks best. I turned it off since some small points of light look a bit like noise and are cancelled out.

You were right to turn off noise reduction. It isn't worth trying with noise reduction on. That is why Canon cameras are popular with astrophotographers - they are about the only ones that have a genuine RAW mode. Nikon cameras are also good, but there are strong rumours that noise reduction cannot be turned *completely* off.

cottonfoo said:

Some cameras work better at astro than others due to them not having such strong IR filters.

This is an issue for more advanced astrophotographers. It only affects the ability to capture emmission nebulae. This thread is about photographing the stars.


Don
--

[cottonfoo]

don4l said:

This is an issue for more advanced astrophotographers. It only affects the ability to capture emmission nebulae. This thread is about photographing the stars.

I disagree. While people want to photograph stars, what they, and everyone else wants to see, is the Milky Way.

[cottonfoo]

don4l said:

Nikon cameras are also good, but there are strong rumours that noise reduction cannot be turned *completely* off.

You can turn it off "completely" by turning your camera off when the "Job NR" flashes on your LCD. The image is still stored, but NR is bypassed.

ETA, you clearly know what you're talking about, so I would be interested in seeing some of your photos, through telescopes or not

Edited by cottonfoo on Wednesday 16th September 22:19

[don4l]

cottonfoo said:

don4l said:

Nikon cameras are also good, but there are strong rumours that noise reduction cannot be turned *completely* off.

You can turn it off "completely" by turning your camera off when the "Job NR" flashes on your LCD. The image is still stored, but NR is bypassed.

ETA, you clearly know what you're talking about, so I would be interested in seeing some of your photos, through telescopes or not

Edited by cottonfoo on Wednesday 16th September 22:19

I *think* that I have uploaded an image of star trails over Mount Teide in Tenerife. If it doesn't work, then I will just have to figure out another way of doing it.


Don
--

[cottonfoo]

don4l said:

I *think* that I have uploaded an image of star trails over Mount Teide in Tenerife. If it doesn't work, then I will just have to figure out another way of doing it.

No you did it fine (as you now know) That was a long exposure!