Archived posting to the Leica Users Group, 1998/01/23

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Subject: Re: [Leica] Light fall-off, not vignetting
From: Five Senses Productions <fls@5senses.com>
Date: Fri, 23 Jan 1998 10:39:50 -0800

I am not sure which anomaly I experienced....all I know is that there was
easily visible darkening of the corners.

At 10:57 PM 1/22/98 -0500, you wrote:
>In a message dated 98-01-22 16:46:25 EST, you write:
>
><< 
> Francesco,
> 
>  >stellar performers.  The 35 introduced visible corner vignetting
> 
>  [snip]
>  
> >The 35/1.4 also worked very well wide open at night to capture scenes
> >of a street market in Bangkok, lit only by street lamps.....no 
> >vignetting
> 
> How can this be??? You mean no "visible" vignetting???  Isn't vignetting
> a physical property of the lens due to construction parameters??  Or am I
> wrong or missing something (again)???
> 
> Dick Hemingway
> Norman, OK 
> 
>  >>
>Fransesco and Dick,
>
>I think vignetting is the physical obstruction of the light path that cuts
>into the image on the film, usually at the corners, and usually caused by
>filters that protrude too far in front of the lens or an incorrect lens
shade.
>What Fransesco is referring to, I think, is not vignetting, but light
fall-off
>due to the fact that with a wide-angle lens, the distance to the corners is
>substantially farther that to the center. It's the inverse-square law acting
>here.
>
>Charlie
> 


Francesco Sanfilippo,
Five Senses Productions
webmaster@5senses.com

http://www.5senses.com/