[Pentaxosaurus]

I got a WR together with my K5 and I find its IQ amazing, regarding the price tag. It's very sharp–at least if stopped down by 1 or 2 steps, and @55mm and shortest distance it has almost macro lens qualities. Since neither the ALII nor the WR seem to receive as much praise as mine would deserve I'm wondering if I was lucky and Providence picked a good sample? Or has Pentax QC improved lately??
Docrwm, perhaps you could include a test at close focusing distances.

[Blue]

They both have SMC and SP coatings so I think the only variation you will see is from individual lenses when comparing the AL II to the WR. I think an AL II lens I used to have was better than my current WR but am certain it was just the difference in the units.

[Tanzer]

Is it wrong that a want the DA version to match the style of the DA 50-300?

Think I am in OCD overload!!!

The current Pentax lens lineup is all over the place, as far as cosmetic appearances go. Not sure how many lenses you have, or what you are planning to buy, but if you hang out here on PF long enough, your will become powerless to resist buying more and more lenses. There are the DA Limiteds, FA Limiteds, and the DA* lineup, which look similar within their lineups, but are much more different looking across lineups that than comparing the 18-55WR and the DA 50-300. I think this is just a ploy to get you to buy a complete set of each series.

And then there are old lenses, you will start to accumulate those too, and each of those has a certain look too, which will cause you to eventually give up any thought of keeping things looking consistent. There's no point in resisting, just embrace the madness.

[Docrwm]

They both have SMC and SP coatings so I think the only variation you will see is from individual lenses when comparing the AL II to the WR. I think an AL II lens I used to have was better than my current WR but am certain it was just the difference in the units.

I recall, but can not find at the moment, a thread about extra water repellent coatings for the WR lineup of lenses. It may be a complete brain fart on my part but I do have a recollection of reading that either here or elsewhere.

[pacerr]

I'm wondering if I was lucky and Providence picked a good sample?

I'd go for the luck of the draw in this case. Here's an admittedly over-simplified look at manufacturing QA in general that may be useful. A sort of histogram of QA.

For the sake of discussion let's note some typical considerations for a DA-kit lens vs. a Star* or Limited quality lens.



Note 1 - Regardless of type or cost there'll always be a few random, defective items that for some reason escape notice in the QA screening process and make it into the market place. Higher cost items have a higher QA sampling rate as part of the inherent price tag. A 100-percent QA screening rate and life time guarantee can be extremely expensive, but possible.

Note 2 - depending on things like the quality of the design and materials, age of the tooling, experience of the work force and quality control measures the chance of getting a better or worse example of the lens may be spread over a wide bell curve or may be concentrated near the high end of the curve.

Note 3 - the chances of getting a best quality lens is much greater of course as more expense is put into the manufacturing process. Random events will ensure there will still be less-good lenses to the left side of the distribution curve - just fewer of them.

Note 4 - but the interesting thing is there's still a chance that random events will produce a serendipitous winner on the far right side of the curve with even the lowest cost lens - within the constraints of the less expensive materials of course. You may have to search through a LOT more low-cost lenses to find that hidden 1 in 10,000 gem though.

I had an example of that a few years ago. I was fortunate enough to have three DA 50-200s in hand at the same time for side-by-side comparison and time enough to explore them. Two of them produced so-so, middle of the curve results as expected. The third one however was a real stand-out in image quality despite having a flaw in the lettering on the aperture ring. Those that can only experience a single sample of a given lens can only go by reviews and prior personal experience in judging that lens.

When a new product comes out or there's a disruption in the materials, manufacturing or QA process there'll be more random events to the left side of the curve unless extraordinary effort and expense is made to weed out the anomalies until normal activity returns.

A basic understanding of manufacturing processes and QA sampling helps reduce the frustration of finding gear you're satisfied with. Ultimately, you really do get what you pay for, but sometimes you just might get lucky anyway.

H2