which lens to buy?

I recently got my first camera, a pentax *ist with 28-70mm lens, but now i am looking for another telephoto/zoom lens. I was looking at the pentax dedicated 70-300mm lens and also the tamron 28-300mm di xr lens. I know it would be useful to have one lens for all jobs but is this worth the price difference and is it better to use a pentax lens with a pentax body?

please reply
-haz

If you buy the Pentax lens you can be sure of an accurate match of tolerances with the camera body, the focusing ring and aperture ring (where there is one) will always rotate the same way and avoid confusion, the colour balance of the lenses will match, and probably the image quality will be better as well.

I'm a great fan of Pentax lenses for their clean, crisp image quality and freedom from flare. I've tried other lenses, and with only a couple of exceptions they have been an expensive way to learn that I prefer Pentax!

And bear in mind that the greater the zoom ratio, the more difficult it is to build a lens of high quality. Which means they are either of poor quality, or great cost, or both.

Unless you REALLY need just one lens, you'll be better off with two or three.

G

Hi,
I used to have a Pentax FA 28-70 f4 AL and 80-320 which I used with a Z-70 and later an MZ-3. The 28-70 was a great lens for its size, though a little slow. I wasn't overly impressed with the 80-320; it was slow, noisy and a little soft though its range was good.

When I sold the Z70 I replaced both SMCs with a Sigma 28-300 macro zoom (they've recently bought out a slightly revised version), which got a great review in AP. They compared it with the Tamron 28-300 (as did I in the shop) and I think the Sigma came out better on image quality and price. I found no great difference in build quality or focus speed/noise but the Sigma was a lot cheaper. They're both comsumer lenses, but things have come on a lot in this market in the last 5-10 years.

I keep my 28-300 for general use, but I have some primes (Sigma 105 EX, Pentax FA 28 AL, 43/1.9) for other work. I'm more impressed with the Sigma than I was with the Pentax 80-320.