Ok
A few months ago I bought a Sigma 135-400 f4-5.6. It's a fairly cheap lens but doesn't have Sigma's nice HSM focus jobbie. Been happy with the results and has produced some images I'm happy with.
Recently treated myself to a Sigma 70-200f2.8 EX DG APO IF HSM...you know the one.
What I'm thinking is, if I splash out on a 2x TC I'll have the same focal length and a faster focusing lens along with all the benefits of the EX HSM etc and still retain the reasonably fast f5.6 aperture.
Is there really any advantage of using the longer lens? Or am I going to be better off with the shorter one with the TC? If so I'll out the 135-400 and buy a 2xTC.
Answers/brainstorms/off topic rants welcome!
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