Author Topic: Starburst  (Read 247 times)

DNSJR

  • NG Supporter
  • **
  • Posts: 60
  • You ARE NikonGear
Starburst
« on: November 07, 2017, 00:41:52 »
My first try at a starburst; appreciate your thoughts; shot with Tamron 24-70,f/4.5, 1/1600 sec, I realize now, I should have used a smaller aperture, thank you
DNSJR

Bjørn Rørslett

  • Fierce Bear of the North
  • Administrator
  • ***
  • Posts: 7942
  • Oslo, Norway
Re: Starburst
« Reply #1 on: November 09, 2017, 00:27:28 »
Typically using the smallest aperture on your lens, or the next smallest, will ensure a nice "star burst" effect. Some lenses do deliver this earlier on the aperture scale, though. One has to experiment.

This Tamron lens might be a good candidate for "star burst" apparently. Experiment with it under different setting and subjects to learn what it can achieve.

Roland Vink

  • NG Supporter
  • **
  • Posts: 813
  • Kindly Kiwi of the South Pacific
    • Nikon Database
Re: Starburst
« Reply #2 on: November 09, 2017, 03:47:34 »
Lenses with straight edge aperture blades will give the cleanest, most sharply defined diffraction stars. The effect becomes stronger at smaller apertures (diffraction stars are an edge effect, and the ratio of edge length to area increases at small apertures).

Curved aperture blades will generate only weak diffraction stars since the curve causes the points to become spread out. As the aperture closes down the star burst improves as noted above, and also because the sides of the opening becomes relatively straighter as the curvature of each blade is covered by the next overlapping blade.

A perfectly round aperture won't produce diffraction stars at all, you will get a diffuse glow around any point sources of light (which could be considered a star burst with infinite number of points). That's also why you don't get star bursts when the lens is at full aperture.

An odd number of aperture blades will generate stars with twice as many points, producing delicate multi-pointed stars. For example a 7-blade aperture will generate 14-point stars. An even number of aperture blades will generate stars with only the same number of points but they will be stronger because the opposite pairs of blades produce overlapping points. For example a lens with 8 blades will produce strong 8-point stars.

David H. Hartman

  • NG Member
  • *
  • Posts: 1741
  • I Doctor Photographs... :)
Re: Starburst
« Reply #3 on: November 09, 2017, 03:53:25 »
An aperture with straight blander is best. Seven blade apertures give fourteen spokes, nine gives eighteen. [I use f/11 or for stronger spokes f/16.] I  avoid f/22 and I avoid f/32 like the black death. The spokes are diffraction spokes. The more you stop down the more general diffraction as well as the stronger the star burst. If in doubt most probably use f/16.

Dave Hartman

I Edited one sentence above for clarity. 
Dave Hartman The Handy Tool Maker.™

DNSJR

  • NG Supporter
  • **
  • Posts: 60
  • You ARE NikonGear
Re: Starburst
« Reply #4 on: November 09, 2017, 09:31:57 »
thank you all, I really appreciate the information, most helpful
DNSJR