Quote:
Originally Posted by 5ash
I have taken two photos of a powerpole , the first at prime focus (F10) and the other using a focal reducer.How can i estimate the equivalent focal length using the reducer by comparing the photos. The photos are shown below.
I'd be grateful for some help . regards philip
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Firstly you need to stand on you head
to orient the pole.
To be honest the pics will be a bit difficult to use. You need to take an image of something with well defined marking that you can measure on both images. You then measure a reproducible distance on the photos in either pixels or mm and divide one number into the other. This gives you the reducing power. Then multiply this by the prime focal length.
Simple really
