previous page in this Vignetting
article
This graphic is a little harder to understand , but it should show that
you still have the same amount of light falling onto the negative as
you did before with the smaller apertures , but now more light in the
centre of the frame from the unshaded part of the aperture.
As we only would open up the aperture in low light situations to allow
more light to be exposed to the film the light falling in the centre is
actually the correct amount as indicated on your light meter , but
because of the shrouding on the edges , we have less light onto the
corners of the frame.
This causes the dark corners of the vignette effect.
With the standard 80mm lense on a Kiev60 this all starts to go off at
approximately f8 and larger.
An interesting thought to ponder is , ¨Why buy a lense that has a
large f of say f2.8 when we have to close it down to f8 to prevent
vignetting , when a cheaper f4 lense will need to be stopped down to f8
as well , Whats the point ?.¨
Well .... thats something to talk about in a later article. :-D
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