Sigma 150mm ex dg
I have emailed Sigma 4 times in the last 18 months to find out if it is going to be available in Pentax mount and each time they reply with the answer that yes it is but they have no time scale as to when we can expect it.
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Mike will have a more informed opinion for you though.
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Sorry to get you started Mike

It has been said that the SMC Pentax 200mm Macro is arguably the best macro lens ever produced by any company.
The Sigma 180mm 1:3.5 EX DG Macro lens is about the closest you'll find. Grab one while you can. If Sigma ever do make the 150mm available in K mount they might just stop producing the 180mm. It really is a very good lens.
Peter E Smith
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Mick
mxds
Member
Norfolk. UK
Interested in the above lens to give me a little more reach than my old SP90 Tamron for "shooting" dragons and butterflies. Your thoughts and experiences would be appreciated
Thanks Mick