View single post by jk
 Posted: Fri Jun 1st, 2012 11:53
jk



Joined: Mon Apr 2nd, 2012
Location: Carthew, Cornwall, United Kingdom
Posts: 6874
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Eric wrote:
Interestingly and somewhat puzzlingly, the super duper 24-70 has an atrocious hotspot when used for IR. it's almost 3/4 of the frame...making it unusable. I haven't considered why it works so well with colour images but fails so miserably with IR?


Must be the something to do with the design and the glass used.

I think that the ED or new special high refractive index glasses may not behave so well as the older heavier lenses that were made of all the same type of glass.
That is purely a guess ..... Someone out there will know.



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