John wrote: JL> I have a Pentax MZ-5n which I use mostly with the Sigma 28-80 F3.5-5.6 JL> Aspherical which I got with the camera. Photos seem to have less "punch" JL> (particularly when the sun isn't shining) than ones I took on an MZ-50 with JL> standard Pentax 28-70 lens.
No wonder. This particular lens (FA 28-70/4) has very good contrast. JL> I'm wondering whether that Sigma zoom is a bit too "budget". I'm tempted to JL> replace it with a 28-105 internal-focussing (I just HATE that filter ring JL> turning). Have considered Pentax, Sigma, Tokina and Tamron. Like the idea of JL> faster lens, so Sigma 28-105 F2.8-4 very attractive, but Sigma again? Need JL> to keep below 200 UK pounds (ideally). I heard the only good Sigma in this range is the 28-70/2.8. JL> I've noticed that IF lenses seem to "whirr" more on focussing. Could the JL> increased load on the camera auto-focus drive be a problem? This is likely due to the steep stroke rather than the load. IF by design moves less glass on shorter range, so it's supposed to put less strain on the AF motor. JL> I'm sure Pentax JL> would say using anything but a Pentax lens might wreck the camera, but what JL> is the truth? The general consensus is that Pentax lenses have faster AF. The communication protocol between the lens and the body has a significant role, and at least Sigma hasn't licensed it. Servus, Alin - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
