Advice Please. 70-200 lens for K5

[Blueheeler]

Folks,

I'm considering upgrading my long lens to a new 70-200. My two best options at the moment are the Sigma 2.8 APO EX DG OS HS and the Tamron SP AF f/2.8 Di LD (IF) Macro. These match my criteria of being long enough and fast enough for portrait work to action shots. I already have the 10-70 range covered with a couple other pieces of glass and can't really see a need to go longer than 200. The K5 has an APS-C chip anyway so it's an effective range of 320 or thereabouts.

Does anyone have any experience of either or both of these?

Also, I note the Sigma has inbuilt image stabilisation which the Tamron does not. My K5 already has on board shake reduction (which gives me satisfactory results) and I understand that one does not use both body and lens stabilisation simultaneously.

Any thoughts on the Sigma OS stabilisation being superior/inferior to the K5 on board stabilisation?

Any other comparative thoughts between the two?

The Sigma is about AUD$450 more than the Tamron so is it $450 optically better, or is that just the price of in-lens stabilisation.

Any comments appreciated.

Thanks

Ray

[arthurking83]

I've had good experience with the Tammy lens.
Had it for about 4 years now and it's performed admirably considering the price.

I suppose the difference between in camera IS and in lens IS is that when you choose in lens IS, you not only get the stabilisation for the actual exposure, the view through the finder is also stabilized too, so that it's not such a shaky experience.

I'd recommend that you go with the Tammy, simply because of the image quality that the Tammy can achieve.

[Kym]

Both are good options.
In lens stabilisation means a more stable viewfinder image but less battery life.
The Tamron is best value.

[Cage]

I have the original Sigma 70-200 f2.8 APO EX and it was as sharp as on my now gone K5.

[olefella]

+ 1 for the tamron, i find it very good for sport ie bikes.

[KevPride]

Bonus with the tammy is the excellent tamron 1.4 TC - would seem a perfect fit if you wanted longer length without much IQ loss.