Archived posting to the Leica Users Group, 1998/02/17

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
Subject: [Leica] Star Diffraction Pattern?
From: Robert Rose <RJR@usip.com>
Date: Tue, 17 Feb 1998 14:12:32 -0800
 
I thought one of our more technical minded members might give an opinion on the cause of an interesting "feature" of my Leica lenses.

I have noticed that when shooting available light pictures with my 35mm Summicron-M ASPH, small very bright light sources (almost point sources?) produce a star diffraction pattern on the image, almost like the result from a star filter, in the pattern of the aperture blades.

I have also noticed this with my Vario Elmar-R f/4 35-70.

For example, look at: http://amishalom.org/images/night.jpg

(The image was on Reala, in an R4sP.  I used spot metering on the houses, and the camera chose around 5 seconds or so at f/4, wide open.  Scanned the image into Photoshop with the HP scanner, then used auto levels, saved as a progressive jpg.)