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next PZ lens test report: Sigma AF 150mm f/2.8 EX HSM DG APO macro OS (EOS)
#48
[quote name='Klaus' timestamp='1312885450' post='10548']

Really ... ?

[url="http://savazzi.freehostia.com/photography/workingdistance.htm"]http://savazzi.freeh...ingdistance.htm[/url]

[/quote]



Well, as long as the lens has an IF design (no change in length while focusing), I think the formula is still valid (or am I missing something?)....



The figures given for Sigma 180mm in this article proves it. The WD was calculated as 232mm for 1:1 ratio. The physical length of the Sigma 180mm f/3.5 is 179,5 mm. The flange focal distance for F-Mount is 46,5 mm and the MFD for Sigma lens is 460mm.



460 - 179,5 - 46,5 = 234mm (not sure about the 2mm difference from the 232mm give in the article, maybe the precise length of the lens was different for the F-mount version).



Serkan
  


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next PZ lens test report: Sigma AF 150mm f/2.8 EX HSM DG APO macro OS (EOS) - by PuxaVida - 08-09-2011, 11:29 AM

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