Got this lens a few days ago, didn't really have time to do a thorough review, here I'm just sharing some hands-on experiences, and some sample photos taken w/ it on a K5.
The lens is much smaller than I expected, just a little bit bigger than the 1855 kit lens. But it seems to be very well built, feels solid and sturdy, no shaking even when the lens is fully extended. I don't have the DA17-70 w/ me anymore, but I do feel this new 18-135 lens is better built than the DA17-70.
AF speed is very fast, faster than any SDM lens I've ever used, and I've used all the current SDM lenses. AF is very quiet too, similar to the SDM if not quieter. Focusing ring does not turn during AF, which is a big plus to me. Oh btw, it does feature quick-shift for eash AF/MF shift. Focusing ring is located close to the camera body end, not like all the other Pentax lenses, which I think is a very clever design 'cause we won't be using the focusing ring much for a lens like this, better just put it somewhere out of the way.
The lens can focus pretty close, about 40cm all the way from 18 to 135mm, pretty useful when using it for some closeups. The round shaped aperture blades do help getting smoother bokeh. Aperture is still pretty decent at near 70mm, here is the max apertures at different focal range:
18-20mm：F3.5
21-28mm:F4
29-68mm:F4.5
69mm-135mm:F5.6
Optically the lens is pretty sharp through out the focal range, performs the best from 24 to around 100mm, sharp enough even used wide open at the wide or tele end, if focused properly. It produces very nice contrasty photos w/ pleasing colors, plus its small and compact size, fast AF, great built quality and weather-resistant design, it's one of the best travel or walkabout lens Pentax currently is offering I think.
Oh I forgot to mention, the lens looks very nice too, especially when mounted on K-5:
Here are two comparison photos between this new 18-135 lens and a 18-55 kit lens:
The lens is much smaller than I expected, just a little bit bigger than the 1855 kit lens. But it seems to be very well built, feels solid and sturdy, no shaking even when the lens is fully extended. I don't have the DA17-70 w/ me anymore, but I do feel this new 18-135 lens is better built than the DA17-70.
AF speed is very fast, faster than any SDM lens I've ever used, and I've used all the current SDM lenses. AF is very quiet too, similar to the SDM if not quieter. Focusing ring does not turn during AF, which is a big plus to me. Oh btw, it does feature quick-shift for eash AF/MF shift. Focusing ring is located close to the camera body end, not like all the other Pentax lenses, which I think is a very clever design 'cause we won't be using the focusing ring much for a lens like this, better just put it somewhere out of the way.
The lens can focus pretty close, about 40cm all the way from 18 to 135mm, pretty useful when using it for some closeups. The round shaped aperture blades do help getting smoother bokeh. Aperture is still pretty decent at near 70mm, here is the max apertures at different focal range:
18-20mm：F3.5
21-28mm:F4
29-68mm:F4.5
69mm-135mm:F5.6
Optically the lens is pretty sharp through out the focal range, performs the best from 24 to around 100mm, sharp enough even used wide open at the wide or tele end, if focused properly. It produces very nice contrasty photos w/ pleasing colors, plus its small and compact size, fast AF, great built quality and weather-resistant design, it's one of the best travel or walkabout lens Pentax currently is offering I think.
Oh I forgot to mention, the lens looks very nice too, especially when mounted on K-5:
Here are two comparison photos between this new 18-135 lens and a 18-55 kit lens:
