Six months ago, I would have been happy with my Pentax 18-250mm, which is remarkably versatile. It's definitely a "super zoom." However, for a do-all lens if you are just carrying the camera with no extra lenses, it falls short for a number of reasons.
1. It's heavy and somewhat bulky compared to the 18-55mm kit lens.
2. Held downwards, zoom creep happens - the lens extends on its own by gravity. It's a nuisance to have to lock it down in the 18mm position, and when unlocked, hold onto the zoom ring to keep it from extending when shooting down.
3. It's not weather resistant. I'm contemplating a trip to Hawaii, and I want the lens to be as effectively water sealed as my K-5.
So I recently purchased the Pentax 18-135mm WR zoom. I think this is the ideal "walk around" single zoom lens for the K-5. Here's why:
1. Perfect match for the K-5. Although it doesn't zoom as far as the 18-250mm, the K-5's 16.2 megapixel pictures can give you a lot of crop latitude. Also, although the lens isn't particularly fast, with the K-5's extended ISO range and more than acceptable IQ at high ISOs, that isn't as much of a factor.
2. It's lighter than the 18-250mm, and only marginally heavier than the kit zoom 18-55mm.
3. It's just a smidge longer than the 18-55mm, and easily fits into most small camera holsters/pouches designed for kit lenses.
4. There is no zoom creep - no need to fuss with zoom locks or worry about shooting downward.
5. Any minor distortion or CA issues can be taken care of in PP.
6. Auto focus is blazingly fast, quiet and accurate with the DC drive motor on this lens. I can get quick shots of opportunity without overly disturbing humans or animals.
7. It's weather resistant - using it in a rainstorm will be a minor inconvenience and there will be no worry about water getting into the works.
8. The zoom range will be sufficient for 90% of the shooting I will probably be doing, with a 35mm film equivalent of 28 to 207mm. In my old film days, I would have given anything for a lens like this.
9. The pictures I'm shooting with it show great color fidelity and sharpness. Any drop off of sharpness at the edges is minor and not a concern if you shoot with cropping in mind.
10. With the great zoom range, there is no need to swap lenses constantly in the field and introduce the risk of getting dust or other crud on the sensor.
11. I like the manual focus override feature as well, allowing fine tuning and special effects without using the selector switch.
So the upshot is that my vote goes to the 18-135mm WR. It may not be the best at everything, but it's excellent for almost every situation, and very packable.
John
Last edited by PALADIN85020; 07-19-2011 at 11:12 AM.
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