Nikon with a Sigma 100-300mm f4 ?

[Mike.P]

I currently have a pretty substantial Pentax setup and was thinking of upgrading the the new K-7 pretty soon but after reading reviews it seems the AF is still pretty slow when compared to say the D300.

I have therefore decided to keep my current setup and within the next few months look for a used D300 and run 2 cameras, using my Pentax for the bulk of photography and the Nikon for anything requiring fast focus.

With this in mind I have managed to source a Sigma 100-300mm f4 in Nikon mount from a Jessops not too far away for £599 whch I think would be perfect for what I need but am a bit concerned about the lack of SR/VR/OS whatever you call it. With my Pentax having SR built in I am able to use my Bigma and 70-200mm f2.8 at speeds down to 1/180 with no tripod/monopod but wondered how people get on with the Nikon and largish lenses ... I know the ISO performance of the D300 will allow me a few stops.

Thanks.

[Joe T]

Will this be largely for warplane photography?

[Mike.P]

Will this be largely for warplane photography?

Amongst other things, yes. Basically anything fast moving.

[puddleduck]

As things will be fast moving, this requires fast shutter speed to freeze motion. Therefore you don't need VR / IS etc.

I do the odd airshow with a 300mm f/4 + TC and have no problem getting prop blur + sharp shots at 1/160 with that combo (no VR)