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Building your own aperture filters
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PostPosted: Wed Sep 12, 2007 12:59 pm    Post subject: Reply with quote

peterqd wrote:
You're a little late Carsten. Leonardo da Vinci got there first!
http://en.wikipedia.org/wiki/Image:Madonna_Benois.jpg


Very Happy

But what I mean is the opposite, the edge of the circle will be soft whereas the inner circle will be clearly visible, you know?


PostPosted: Wed Sep 12, 2007 2:37 pm    Post subject: Reply with quote

LucisPictor wrote:
peterqd wrote:
You're a little late Carsten. Leonardo da Vinci got there first!
http://en.wikipedia.org/wiki/Image:Madonna_Benois.jpg


Very Happy

But what I mean is the opposite, the edge of the circle will be soft whereas the inner circle will be clearly visible, you know?


Yes, I get it! Smile Your words "some nice soft-edge highlight circles" made me think of halos.


PostPosted: Wed Sep 12, 2007 4:27 pm    Post subject: Reply with quote

I thought so... Wink


PostPosted: Fri Sep 14, 2007 1:35 pm    Post subject: Reply with quote

peterqd wrote:
I wasn't exactly a success at physics at school Smile Am I right in thinking that the diameter of the aperture = the focal length divided by the f stop? (i.e f/8 on a 50mm lens = a 6.25mm diameter aperture).


I just found the answer to this in Wikipedia http://en.wikipedia.org/wiki/F-number and I was right. An f/11 aperture on a 135mm lens wll be just over 12mm diameter and on a 35mm lens just over 3mm diameter.