[SA Chris]

Quite keen on getting some wildlife pics  (whales and eagles?) when we are in Canada, so toying with the idea of getting a teleconverter, as I can't afford a big zoom.

Current lens is a full frame Sigma 70-300 APOmacro, for using with my Pentax *ist D (non full frame sensor). I have had pretty good results using the lens for wildlife in SA, would it make sense to got for a sigma converter also? 1.4 x or 2 x.

And I know I will lose an f-stop or two, am taking a small tripod as well.

Thanks

Chris

[Johnny Brown]

Even a 1.4 with the small sensor give you an EFL of over 500mm. That's a tricky thing to handle, especially when you'll be wide open at f8. I'd be tempted to stick with the lens on its own, accept you won't be able to get exhibition quality results, and crop in after.

[dave]

you only really want to be fucking with TCs on 2.8 lenses or faster. the focusing would be harder at f/8 too.

[SA Chris]

It's an f5.6 lens, but I guess the argument is still valid. Cheers I wasn't sure if it was a good idea or not. Probably stick with the cropping idea.

Anyone know any good noise reduction software

[Johnny Brown]

I guessed 5.6 - a 1.4x will give you an effective aperture of f8, a 2x f11. Autofocus is unlikely to work, and the viewfinder will be dark. As Dave said, I don't bother except on fast lenses.

[SA Chris]

Cheers, will probably not bother then.