[k_dellaquila]

How does the weather and dust resistance of the WR lenses compare to the DA* lenses?

[bymy141]

The weather and dust resistance is the same.
It differs in the auto focus drive. DA* uses SDM (internal lens motors), instead of the WR which uses the "old fashioned" screw drive.

- Bert

[Blue]

In addition to what bymy141 said, the DA* have both a SDM motor and can be operated by screw drive. However, SDM bodies can't take advantage of the screw drive with the exception of early K20d bodies.

[aerodave]

The exception to the dual drive system is the DA* 55mm f/1.4. It is SDM-only.

And, Blue, I believe you're thinking of early K10D firmware that allowed screw-drive operation. That's because when the K10D was first realeased, those were still power-zoom contacts and there was no such thing as SDM yet.

[Blue]

The exception to the dual drive system is the DA* 55mm f/1.4. It is SDM-only.

And, Blue, I believe you're thinking of early K10D firmware that allowed screw-drive operation. That's because when the K10D was first realeased, those were still power-zoom contacts and there was no such thing as SDM yet.

I didn't realize the DA* 55mm was SDM only. I would be annoyed if I replaced my FA 50mm with it to find out I can't use it on my MZ-3. You are correct about the K10 in that I was referring to the early firmware.

[Adam]

How does the weather and dust resistance of the WR lenses compare to the DA* lenses?

Don't quote me on this, but it was my understanding that the weather sealing on DA* lenses is a notch better than that of WR lenses. DA* lenses use a special coating on their front lens elements to protect against dust and erosive scratches. I also believe that you wouldn't be able to take a WR lens under the shower, as they don't have internal zoom.

[Blue]

Don't quote me on this, but it was my understanding that the weather sealing on DA* lenses is a notch better than that of WR lenses. DA* lenses use a special coating on their front lens elements to protect against dust and erosive scratches. I also believe that you wouldn't be able to take a WR lens under the shower, as they don't have internal zoom.

The WR versions of the DA 18-55mm and 50-200mm are supposed to have the SP coating on the front element.

[aerodave]

Don't quote me on this, but it was my understanding that the weather sealing on DA* lenses is a notch better than that of WR lenses. DA* lenses use a special coating on their front lens elements to protect against dust and erosive scratches. I also believe that you wouldn't be able to take a WR lens under the shower, as they don't have internal zoom.

The DA* 16-50 and DA* 60-250 are not internal zoom. I've never showered with them, though.

[Adam]

You're right, they're not. I guess only the 50-135mm is (which I use just because it has the great weather sealing ).

[Blue]

The DA* 16-50 and DA* 60-250 are not internal zoom. I've never showered with them, though.

Pentax advertises and sells both of those as [IF] so they are better sealed by default.

[johnmflores]

Pentax advertises and sells both of those as [IF] so they are better sealed by default.

There's a difference between Internal Focus and Internal Zoom.

Internal Focus means the front element doesn't rotate as it focuses, so you can mount a CPL and not have to adjust.

Internal Zoom means that the length of the lens doesn't change as it zooms.

[Blue]

There's a difference between Internal Focus and Internal Zoom.

Internal Focus means the front element doesn't rotate as it focuses, so you can mount a CPL and not have to adjust.

Internal Zoom means that the length of the lens doesn't change as it zooms.

I know the difference. There's more to IF than just the front element turning as well. My point was is that the DA* are IF meaning that the lens doesn't get longer as its focused.

[glanglois]

Pentax describe the * and WR lines differently. Take a moment to visit their site.

WR is described, IIRC, as resistant to splashes and spatters. There's no mention of dust.

I will conclude, until someone dismantles a few of these for exhibition purposes, that "sealed" provides significantly more protection against the outdoor elements.

I'm also hoping that my extended warranty through B&H, one that specifically includes "moisture" and "dust" as well as accidental damage, will help on my new Sigma 18-250 OS if I get careless. First time I took a chance - $60 for three years. I'm clumsy. Call it insurance.

By the way, which opinions do you have on putting an O ring or wide rubber band around the lens-camera joint? Doesn't necessarily help with dust among the lens elements from telescoping a zoom but may seal some environmental debris from getting into the camera box. Rather have it in the lens than scattered everywhere inside the camera, K-7 in this case. One more thing that sounds reasonable but may be nonsense.

[Pentaxor]

as far as weather sealing goes, both lenses are capable of withstanding the elements. so there's no clear indication or proof that the other one's sealing is better than the other. it doesn't matter if it's rainfall, dust, splashes, snow, mud, etc...

the more obvious differences would be , one is heavier, bigger, SDM, fast and fixed aperture and way better IQ, while the other one is smaller, lighter, reliable screwdrive AF, variable aperture and good IQ.

[glanglois]

as far as weather sealing goes, both lenses are capable of withstanding the elements. so there's no clear indication or proof that the other one's sealing is better than the other. it doesn't matter if it's rainfall, dust, splashes, snow, mud, etc...

the more obvious differences would be , one is heavier, bigger, SDM, fast and fixed aperture and way better IQ, while the other one is smaller, lighter, reliable screwdrive AF, variable aperture and good IQ.

You're certainly right about which are the obvious differences but the OP was asking about differences not so obvious.

And I have to disagree there.

There are substantial variations among the elements you note: the likelihood of water entering the lens will vary with variances in both the speed and direction of the impinging water, the threats posed by dust will vary with the size and velocity (speed and direction) of the impinging particles, threats posed by liquids may vary with differences in viscosity, etc.

A gentle spatter of water is very different than an atmosphere of very fine dust. Salt water can create a different threat than rain.

Etc.

As you note, we are not (yet) aware of any proof that WR is less effective or is effective in fewer circumstances. But I'm arguing (in a pleasant way, I hope) that Pentax is clearly indicating a difference and they would know best.

Now, if you'd like to offer up your lenses for dissection ......