23 January 2012

Photo Tips #5

Top tips for you and your camera

# 5 - SHOOTING STAR TRAILS

If you get as excited about the night sky as I do - then you will love this tip. If you watch the Stargazing show three nights last week you will have seen some quite spectactular star trail images. Well now you can try it for yourself.

There is so much to see in the night sky on a clear, cloudless night that I often cant resist getting my camera out and having a play. Astrophotography is an exciting area of photography and star trails are an easy introduction to this field.

You need your camera on a tripod (or a solid surface); your lens wide open (f22 or as high as it'll go); and have some way of being able to control how long an exposure you can capture with either a cable release or remote shutter release.

You can use a telephoto lens and try shorter exposure times, but a wide angle lens will give you more of the night sky in your capture - but you will need a longer exposure. Anything from 10 seconds to a few hours - depending on the effect you are after.

This might be an easy technique but you do need to experiment - making notes of your settings and your results. This is the only way to improve and develop your own style.

Light pollution can give you all sorts of problems - so a trip out into the countryside away from the orange street lights is recommended. If you live near the sea then point your camera out to sea it is usually darker that way!

Here's the technical stuff you need to consider. Try starting at ISO 400; focus you lens to infinity; set the lens to the widest aperture and point your camera to the sky. If you want to see the stars circling around a fixed point then you will need to point your camera to the North Star (easy to find - edge of the plough and 2.5 times above). However if you want to see how your favourite constellation moves across the sky then point your camera at that.

30 seconds of Sirius above the trees
Your experimenting will determine how long you set your exposure for. A recent 30 second exposure resulted in this tiny amount of movement from Sirius across the sky. You might need a cable release or a remote release if you decide to do exposures of minutes or hours.

The beauty of this technique is that you determine exactly what look you are after. Your abilities will improve with experimentation and you will develop your style and look.

This 10 second exposure taken in July at 11.30pm captures a satellite (top left)

If you think you'll wait until the summer and do your star gazing then when it's warm - then that is fine but be prepared for different problems. The image above was taken at 11.30pm and it's not really properly dark. I captured a satellite (top left) and the mist rolling in down the dale. It wasn't what I was after but it was a lovely capture none-the-less.

If you choose to capture shorter exposures you can stitch them together in photoshop (in a similar way to panoramas) try investigating Chris Schur's Star Trail Action. You will get the equivalent of a single long exposure.

The looks, idea and beautiful results are limitless.

Have fun capturing your stargazing masterpiece.

Next top tip - Print your Photos - next week.

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