Help with star trails...
Discussion
So it's a clear night tonight and I've been out trying to get pics of star trails.
I've been doing 10-15 min exposures so the trails aren't that long really but I'm already coming across a problem that I imagine will only get worse with longer exposures.
Basically, the sky is too bright. The starts are showing up clearly but the sky is just bright blue at around 10 mins. I imagine it's light pollution really (being in a built up area) but is there any way I can stop this?
I'm shooting with the aperture wide open (read this is best somewhere online) so could close it down a bit but then I'm going to reduce the light from the stars aswell.
What setting should I be using?
Cheers
I've been doing 10-15 min exposures so the trails aren't that long really but I'm already coming across a problem that I imagine will only get worse with longer exposures.
Basically, the sky is too bright. The starts are showing up clearly but the sky is just bright blue at around 10 mins. I imagine it's light pollution really (being in a built up area) but is there any way I can stop this?
I'm shooting with the aperture wide open (read this is best somewhere online) so could close it down a bit but then I'm going to reduce the light from the stars aswell.
What setting should I be using?
Cheers
A quick search (it seems to be working at the moment) would have led you to several threads - all of which asking the same question and strangely enough all pointing to the same reference link.
Mr Whynots how to.
which is here if you click
Mr Whynots how to.
which is here if you click
At the moment, the brightness is from the moon. Try in three or four nights' time when the moon will rise much later so won't affect the ambient light until a time when you'll likely be back home in bed.
Too bright after 10 mins (tonight) makes me think you're probably set to around ISO200 f/5 - give or take. You'll get some stars shining through but better to use a wider aperture (if you can) to capture more starlight and shorter exposures to control the ambient/ foreground lighting. This is why stacking is such a popular technique, as it makes startrails so much more accessible within *your* conditions, whatever they may be.
As has been posted, there's a tutorial for urban star trails on my blog. It doesn't mention exact shutter speeds to use because there are so many variables but assume 30sec and go shorter or longer depending if your 30sec test shot is too bright or too dim.
HTH
Too bright after 10 mins (tonight) makes me think you're probably set to around ISO200 f/5 - give or take. You'll get some stars shining through but better to use a wider aperture (if you can) to capture more starlight and shorter exposures to control the ambient/ foreground lighting. This is why stacking is such a popular technique, as it makes startrails so much more accessible within *your* conditions, whatever they may be.
As has been posted, there's a tutorial for urban star trails on my blog. It doesn't mention exact shutter speeds to use because there are so many variables but assume 30sec and go shorter or longer depending if your 30sec test shot is too bright or too dim.
HTH
Also perhaps some stuff of use in the below thread, it certainly helped me earlier in the week.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
The easiest way to get around this is to take several photos and merge them.
Set camera on tripod
Make sure camera is focussed correctly
Use a fairly wide angle lens to capture a nice large portion of the sky
Include something earthbound in the frame for foreground interest
Use a fairly wide open aperture - some of those stars are quite faint and need help to be captured
Use a reasonably high ISO for the same reason as above
Make several exposures of 30 seconds or so, a total exposure of 30 minutes should be ok, so 60 exposures
A remote shutter release is useful to avoid nudging the camera
Stack all the images into one
Voila
There is a piece of software freely available to download, called startrails that will stack the images if you don't already have the software to do that.
Set camera on tripod
Make sure camera is focussed correctly
Use a fairly wide angle lens to capture a nice large portion of the sky
Include something earthbound in the frame for foreground interest
Use a fairly wide open aperture - some of those stars are quite faint and need help to be captured
Use a reasonably high ISO for the same reason as above
Make several exposures of 30 seconds or so, a total exposure of 30 minutes should be ok, so 60 exposures
A remote shutter release is useful to avoid nudging the camera
Stack all the images into one
Voila
There is a piece of software freely available to download, called startrails that will stack the images if you don't already have the software to do that.
Deluded said:
Cheers for the info.
Was shooting at 100iso (to keep noise to a minimum) a around f3.5.
I think my main problem was the moon really. Was quite high by the time I had got going. Will try again tonight if it's clear before the moon rises!
Cheers!
I know what you mean, I went out last night to experiment how it would work in an area with more light pollution as the moon is still quite full. Had to drop to 6 second exposures to stop it blowing out but it still worked.Was shooting at 100iso (to keep noise to a minimum) a around f3.5.
I think my main problem was the moon really. Was quite high by the time I had got going. Will try again tonight if it's clear before the moon rises!
Cheers!
Will be heading waaaaaay out into the desert sometime next week to find some real darkness.
Good luck!
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