08-15-2011, 08:21 AM
[quote name='Brightcolours' timestamp='1313393624' post='10751']
Not sure how that is an advantage. The Sigma f2.8-4 is a stop faster at wide angle. That seems to be an advantage over the Pentax. And when you set it to f4, it is as constant as the Pentax!
[/quote]
I was replying to the OP and his list didn't feature the Sigma 17-70.
[quote name='Brightcolours' timestamp='1313393624' post='10751']
Not so. As I showed above, the Sigma 17-70mm f2.8-4 DC OS HSM is the closest focussing one (1:2.7). It has the added advantage of optical image stabilization which gives a stabilized view in the OVF and is more efficient than the in-body IS from Pentax.
K5 is a nice camera, though.
[/quote]
I myself have the Sigma 17-70 f/2.8-4.5 (the old version) which I think is a great lens. In fact, I think it's the best walkabout zoom lens in this range among all manufacturers due to its versatility. I didn't mention it as the OP didn't seem interested in 3rd party alternatives.
Regarding the Sigma, I think the old version is optically better. It's also quite a bit lighter and its close focusing capability is also better than the new version. The new one gains HSM and in-lens OS. Non IS lenses tend to be better optically than their IS counter-part due to the simplified optical design. Long term reliability may also be a problem with in-lens OS.
Anyway, it's just a matter of preference.
Not sure how that is an advantage. The Sigma f2.8-4 is a stop faster at wide angle. That seems to be an advantage over the Pentax. And when you set it to f4, it is as constant as the Pentax!
[/quote]
I was replying to the OP and his list didn't feature the Sigma 17-70.
[quote name='Brightcolours' timestamp='1313393624' post='10751']
Not so. As I showed above, the Sigma 17-70mm f2.8-4 DC OS HSM is the closest focussing one (1:2.7). It has the added advantage of optical image stabilization which gives a stabilized view in the OVF and is more efficient than the in-body IS from Pentax.
K5 is a nice camera, though.
[/quote]
I myself have the Sigma 17-70 f/2.8-4.5 (the old version) which I think is a great lens. In fact, I think it's the best walkabout zoom lens in this range among all manufacturers due to its versatility. I didn't mention it as the OP didn't seem interested in 3rd party alternatives.
Regarding the Sigma, I think the old version is optically better. It's also quite a bit lighter and its close focusing capability is also better than the new version. The new one gains HSM and in-lens OS. Non IS lenses tend to be better optically than their IS counter-part due to the simplified optical design. Long term reliability may also be a problem with in-lens OS.
Anyway, it's just a matter of preference.