New video: "Why are Stars Star-Shaped?"

rjlittlefield · Post by **rjlittlefield** » Sat Aug 30, 2014 10:20 am

I ran into a great video this morning by MinutePhysics: Why are Stars Star-Shaped?

It addresses how aperture shape changes the appearance of point sources back at the sensor.

The link goes to YouTube, so of course you'll have to ignore the seemingly unending stream of inane comments.

--Rik

Chris S. · Post by **Chris S.** » Mon Sep 01, 2014 8:15 pm

Thumbs-up on that video--thanks for the tip!

--Chris

pwnell · Post by **pwnell** » Sat Sep 27, 2014 12:44 pm

Really cool. I remember when I started out with photography way back when, I asked a professional photographer once why I see star shaped patterns on point light sources that I photographed. He replied that my lens must be of inferior quality. I knew he was mistaken...

Just shows you how much misinformation exists even amongst professionals.

ScottH · Post by **ScottH** » Tue Oct 14, 2014 6:58 pm

Really good explanation of diffraction. This impacts our macro photography as well. Any time you introduce an edge anywhere in the optical path energy goes out into those diffraction spikes. The way the energy moves into those diffraction spikes is also impacted by the quality of the optics. From astronomy the better the optics the sharper and thinner the spikes are. Star Testing Astronomical Telescopes by Harold Suiter is a great read on this subject. Highly recommended reading for anyone working with optics.

Scott