jack green
Well-Known Member
Startrail photography allows you to capture the effects of the earths orbit throughout the night on the position of the stars we see.
are the greens home? by -nightlight, on Flickr
There are two main ways to startrail, one is a single extremely long exposure, and the other is compositing many shorter exposures, I am going to explain the single exposure method, as this generally proves more effective
Equipment :
TRIPOD – sturdy one preferably although weights can be hung to keep a less sturdy one stable enough
CAMERA – SLR (DSLR is best although the single exposure method could be carried out on film) with manual over-ride and a bulb setting
Infra red remote or shutter remote,
USEFUL – a super-wide angle lens or fisheye lens
If possible, a battery grip for added battery life
Location:
Away from any lights , not in a city where there is noise pollution,
Conditions: clear night with a small moon – a large moon can add a haze over the sky in the image
preparations – make sure your battery is fully charged, startrailing is extremely energy hungry.
Finding polaris – polaris is the “north star” this is the star which anybody in the northern hemisphere must find,
to find this, find the “plough” or “big dipper” and from the most furtherly right star of the constellation follow straight up and you shall find a very bright star, this is polaris. If you are in the southern hemisphere, the star you must find is Sigma Octantis (the south star).
These stars are crucial to capturing the centre of the movement, they become the centre point of a circular spin of stars.
Single exposure method : this method makes use of your camera's bulb mode which allows the shutter to open for an undefined amount of time , set up your camera and compose the image including polaris, quickly take an image to check the composition, (30s exposure about iso 800 f/4 should do fine just to illustrate the composition)
Camera settings, the only problem is your camera will not meter for super long exposures like needed for a star trail like this, it takes experience to guess the settings but generally they are somewhere in the region of
ISO 200 – F/5-6 – 30 MINUTES EXPOSURE
I suggest using the lowest possible iso, as this will give the cleanest noise free image, 1 f/stop signifies double the amount of light ( f4 = 2x f5 )
Noise reduction : - ensure LONG EXPOSURE NR is ON ! , although this will mean the startrail will take twice as long, it is very worth It as noise can be a real hindrance in super long exposures.
For my star trails I use ISO 200 for 30 minutes, and change the f stop in between 4 and 7 dependant on the amount of light, to allow you to use an exposure that long you must use the bulb setting – this is either shown by the word “bulb” in place of shutter speed, or simply just a line,
ensure your release mode is on remote release , using a remote with delay is best as this allows you to be out of the area before the exposure commences.
Press the shutter release on the remote once, and do any extra lighting you want in the image (wire wool spins, light painting etc) (optional of course!) and then you wait.
Some cameras including mine do not allow an exposure of more than 30 minutes, allow your desired amount of time pass and then return to the camera and end the exposure, you can now move the camera but do not turn it off, allow the long exposure NR to do it's work – it will take the same amount of time as the photo did, (30 minutes exposure, 30 minutes NR) you will now be left with an image, hopefully including a star trail, after practice you can get the hang of the settings you would need for the amount of light there is wherever you are.
Examples.... here are some images I have taken with a 30 minute exposure time
single frame star trail by -nightlight, on Flickr
a broken orb and things by -nightlight, on Flickr
are the greens home? by -nightlight, on Flickr
There are two main ways to startrail, one is a single extremely long exposure, and the other is compositing many shorter exposures, I am going to explain the single exposure method, as this generally proves more effective
Equipment :
TRIPOD – sturdy one preferably although weights can be hung to keep a less sturdy one stable enough
CAMERA – SLR (DSLR is best although the single exposure method could be carried out on film) with manual over-ride and a bulb setting
Infra red remote or shutter remote,
USEFUL – a super-wide angle lens or fisheye lens
If possible, a battery grip for added battery life
Location:
Away from any lights , not in a city where there is noise pollution,
Conditions: clear night with a small moon – a large moon can add a haze over the sky in the image
preparations – make sure your battery is fully charged, startrailing is extremely energy hungry.
Finding polaris – polaris is the “north star” this is the star which anybody in the northern hemisphere must find,
to find this, find the “plough” or “big dipper” and from the most furtherly right star of the constellation follow straight up and you shall find a very bright star, this is polaris. If you are in the southern hemisphere, the star you must find is Sigma Octantis (the south star).
These stars are crucial to capturing the centre of the movement, they become the centre point of a circular spin of stars.
Single exposure method : this method makes use of your camera's bulb mode which allows the shutter to open for an undefined amount of time , set up your camera and compose the image including polaris, quickly take an image to check the composition, (30s exposure about iso 800 f/4 should do fine just to illustrate the composition)
Camera settings, the only problem is your camera will not meter for super long exposures like needed for a star trail like this, it takes experience to guess the settings but generally they are somewhere in the region of
ISO 200 – F/5-6 – 30 MINUTES EXPOSURE
I suggest using the lowest possible iso, as this will give the cleanest noise free image, 1 f/stop signifies double the amount of light ( f4 = 2x f5 )
Noise reduction : - ensure LONG EXPOSURE NR is ON ! , although this will mean the startrail will take twice as long, it is very worth It as noise can be a real hindrance in super long exposures.
For my star trails I use ISO 200 for 30 minutes, and change the f stop in between 4 and 7 dependant on the amount of light, to allow you to use an exposure that long you must use the bulb setting – this is either shown by the word “bulb” in place of shutter speed, or simply just a line,
ensure your release mode is on remote release , using a remote with delay is best as this allows you to be out of the area before the exposure commences.
Press the shutter release on the remote once, and do any extra lighting you want in the image (wire wool spins, light painting etc) (optional of course!) and then you wait.
Some cameras including mine do not allow an exposure of more than 30 minutes, allow your desired amount of time pass and then return to the camera and end the exposure, you can now move the camera but do not turn it off, allow the long exposure NR to do it's work – it will take the same amount of time as the photo did, (30 minutes exposure, 30 minutes NR) you will now be left with an image, hopefully including a star trail, after practice you can get the hang of the settings you would need for the amount of light there is wherever you are.
Examples.... here are some images I have taken with a 30 minute exposure time
single frame star trail by -nightlight, on Flickr
a broken orb and things by -nightlight, on Flickr
Last edited by a moderator:
