Sigma 100-300mm f/4 DG EX IF

[cupic]

I am waiting on this lense next week coming from CR kennedy and want to know when I connect this lense with either a Tamron TC or Kenko TC will I get for example in the tamron case 300X1.4=420mm then the crop factor(Of my Pentax K20d,10D), or just 450mm straight out crop factor,also where can I get a good price on Hoya filters local wise


cheers

[I @ M]

Your 100-300 mm lens will always be a 100-300 mm lens regardless of whether it is mounted on a full frame camera or on a cropped frame camera.

A 1.4 teleconverter, extender or focal length multiplier ( whichever name you want to give it ) will only increase the focal length of your lens so it will become a 140-420mm lens.

If you are going to buy a converter I would suggest that you stick to looking at either the Sigma or Kenko pro 300 dg units as they have the better reputations for working with Sigma lenses.

What sort of filter are you wanting to buy?
82 mm filters are expensive, learn to live with it. :D

[arthurking83]

From memory the Tamron TC's are re-branded older generation Kenko TC's anyhow.. so as Andrew said, stick with Sigma or Kenko TC's.

[Nikolas]

Siggy 100-300 is a great lens and will work well with a 1.4 teleconverter.

[cupic]

I have both Tamron and a kenko pro TC and without HSM they work great(as their is a issue with HSM and TC,lot of focus hunting in low light)as said before the sigma TC will work on the sigma glass brilliantly.I have bought Hoya filters O/S and generally postage is slow but the saving are there to be had(EG HOYA 77mm 77 PRO-1 SUPER HMC PRO1 UV @ $68)as for a 82mm filter Im still looking local first.


cheers