The world at night

smoker · 31st March 2010, 12:05 PM

Just been sent the link to this website, which I thought you might enjoy - some phenomenal pics. I do a bit of widefield astrophotography myself, but I've got nothing on these guys.

http://www.twanight.org/

A few of my faves...

Roger · 31st March 2010, 01:34 PM

Which brings me to a question.

I assume a lot of these are composite shots comprising of several relatively short exposure photos blended together, but I know some on here take quite long exposure photos using digital cameras.

How do you do this? Cos every time I try to do a long exposure, no matter what the ISO setting I end up with a photo full of hot pixels.

keeps21 · 31st March 2010, 01:40 PM

Quote:

Originally Posted by Roger

How do you do this? Cos every time I try to do a long exposure, no matter what the ISO setting I end up with a photo full of hot pixels.

Get a new camera?

smoker · 31st March 2010, 03:50 PM

Quote:

Originally Posted by Roger

Which brings me to a question.

I assume a lot of these are composite shots comprising of several relatively short exposure photos blended together, but I know some on here take quite long exposure photos using digital cameras.

How do you do this? Cos every time I try to do a long exposure, no matter what the ISO setting I end up with a photo full of hot pixels.

Roger, the trick to doing star trails with a DSLR is stacking a load of shorter exposures with a "Lighten" blend method, eg in Photoshop or Startrails v1.1, a nifty bit of freeware.

Set your camera to burst mode, ISO to about 400, exposure to the longest your camera will do (eg 30 seconds), fire the shutter release and lock it. Go away and do something else for an hour or two, then when you return, assuming your battery hasn't run out, you will have hundreds of shots to stack. You can take a torch or flashgun to illuminate the foreground.

As for untrailed shots, then you either need a high ISO and dark sky or some sort of tracking platform, like an equatorial mount or Astrotrac. A tracked image will make the foreground appear motion blurred, but you can cut and paste the foreground from another shot, or use the "lighten" blending mode trick.

not spavin · 1st April 2010, 04:46 PM

Quote:

Originally Posted by Roger

Which brings me to a question.

I assume a lot of these are composite shots comprising of several relatively short exposure photos blended together, but I know some on here take quite long exposure photos using digital cameras.

How do you do this? Cos every time I try to do a long exposure, no matter what the ISO setting I end up with a photo full of hot pixels.

I had this issue for the first time the other week. Normally do long exposures of under a minute - tried one for about 10 minutes and while the exposure was bob on, the image was full of hot pixels. Mind, I don't use noise reduction, and I tried it again with about 5 or 6 minutes exposure time and it was fine.

clyde · 1st April 2010, 05:08 PM

i used the stacking method for these pics and used the free startrails software which is very good and easy to use

definitely plan on doing more star trails pics come the warmer weather and clearer nights.

re-hot pixels, i get quite a few when i dont turn on noise reduction but a couple of minutes in lightroom with the spot removal tool fixes the problem.

youmademerealise · 1st April 2010, 10:24 PM

Quote:

Originally Posted by clyde

i used the stacking method for these pics and used the free startrails software which is very good and easy to use

This one?

http://www.startrails.de/html/software.html

What you've used it for looks pretty good, but I'm not keen on this kind of thing....

Quote:

Originally Posted by smoker

Too unnatural if you ask me. Is that with that software do you think?

I'm sure film used to look better than that

clyde · 1st April 2010, 10:45 PM

yeah thats the one mate, class little programme, only downfall is is that mine sometimes starts up in german, no biggie like as you only need to click to buttons iirc, one to load up the pics and one to convert.

youmademerealise · 1st April 2010, 11:12 PM

Quote:

Originally Posted by clyde

yeah thats the one mate, class little programme, only downfall is is that mine sometimes starts up in german, no biggie like as you only need to click to buttons iirc, one to load up the pics and one to convert.

Yep. That chalet shot looks to have had other unecessary enhancements to me.