Star Shaped streelights in long exposure night shots.. how to??

6644 Views 6 Replies 5 Participants Last post by JoshYent, May 3, 2007

fooddude

Discussion Starter · May 1, 2007

I am new to slr

I notice some dslr photographers shoot no-flash long exposure nightime street shots and sometimes have that "star-shaped" street light effect; other times not and just regular circle shaped streetlights.

What setting/technique makes this most apparent?

I am guessing it is from Av setings? (guessing by different angles of light(picture different shapes of cones for the light?) hitting the front lens opening first, then to the shutter)

If yes, is it usually the smaller aperture w/ long shutter, or larger aperature w/ shorter shutter?

If no, then what makes this effect "pop" more?

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NothingBetterToDo

· #2 · May 2, 2007

i'm no expert - but i think its small apature (higher number) and longer shutter speed.

These are the best examples i could find:

6.0s at f/8...the smallest aperture my camera can go to

whereas this pic is 2.0s at f/2.8

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fooddude

Discussion Starter · #3 · May 2, 2007

Thanks for comparison pics, exactly what I was lookin for

Anyone else have any insight?

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Justme

· #4 · May 2, 2007

Yes, use the smaller apertures, as high as you can go, and this will increase the star effect. The catch is that you loose sharpness at these higher apertures. Not so much a problem on professional lenses, but the cheaper consumer lenses can be quite shocking.

However, another more effective way is to buy a filter. You can buy 4, 6, 8, 16 point stars (the number of rays from each light source). They can be very strong though. Cokin is a good range for this, as you can buy cheap adators for all your lenses and then the one filter works with them all. You can also merge 3 different filters onto the single holder.

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mugley

· #5 · May 2, 2007

The number of aperture blades in your lens is important - with an even number of blades, you get short points of light in the same number as the blades. With an odd number, you get longer beams in twice the number of the blades.

Eg, my 6-bladed 24mm lens produces a squat 6-pointed star (not a night shot here, but it's the same effect):

This one's with a 9-bladed 300mm lens (@ f/8), which produces 18-pointed stars with long beams:

Shutter speed is not really important, but having a small and well-defined source of light is. Stopping down will help achieve this as it reduces blooming on light sources.

Star filters create a different look to stars produced by lenses. This shot from Vermin Inc on Flickr is a good example: