[Eagle_Friends]

The 40mm f2.8 is the best bang for your buck lens in all of Pentax modern lenses.

[causey]

Now, the next question (which is also subjective) is: Is it worth 2.25 times the cost of the DA35/2.4?

Yes, I think so: much better microcontrast (area in which ltds. excel), metal construction (we'll see about the durability of the DA 35/2.4 plastic mount after a few years of usage), diminutiveness (one may call it sexiness).

The 40mm f2.8 is the best bang for your buck lens in all of Pentax modern lenses.

+1

[Docrwm]

Our ratings result from emotional and financial involvement, not just-the-facts-ma'am objective measurements. Ooh, it was expensive, it must be good! Ooh, it was really cheap, such a deal! But we can hopefully draw statistically significant conclusions with a large enough sample size. The fewer the reviews, the larger the grain of salt.

Exactly. The n here is ~40 per lens. Anyway, everyone thinks they can eyeball the #s or that stats are intuitive enough that they can wing it.

[mikeSF]

... The highest rated lens also happens to be the most expensive lens on the list as well. Cognitive dissonance theory would tell us that the cost is why the rating is the highest. People rate things higher that cost more and there are loads of ways this has been demonstrated over and over again (e.g., same radio, same description, two groups, only difference is the cost attributed to the radio, more expensive is rated as a great radio, less expensive as a piece of junk).

interesting finding and thanks for your study of this.

I actually tend to behave oppositely. when considering a lens review, i score largely based on my perceived value of the lens. That is, if there is a strong performer that only cost me $40, i am generally going to conclude that it presents a better value than perhaps a somewhat better performing lens that cost me $500. You can bet when i pay $500-$1000 for a lens i am going to be super picky about its every attribute.

[hoanpham]

I actually tend to behave oppositely. when considering a lens review, i score largely based on my perceived value of the lens. That is, if there is a strong performer that only cost me $40, i am generally going to conclude that it presents a better value than perhaps a somewhat better performing lens that cost me $500. You can bet when i pay $500-$1000 for a lens i am going to be super picky about its every attribute.

So all lenses I got for free should have 10 in rating?
How would you rate the FA85/1.4? This lens is superb for portrait distance, but very poor in longer distance, and still count as must-have even it costs more than 1200 usd used.
Lens reviews are based on personal perception. Without mention the reason and scale, it can only serve as guideline.

[creampuff]

I don't think so. The fact it is the cheapest of the Limiteds, and also one of the most useful lengths, means it is for many people their first and only prime. So many DA40 owners are comparing only to the kit lenses. On the other hand, also consider that the differences in average ratings for these lenses is probably not statistically significant.

It's not just a matter of whether they are statistically significant. The same people are not rating each of these lenses, nor do individuals rate things on the same scale. As Marc pointed out, it's entirely conceivable that a large number of the people rating the DA40 might have a different perspective than those rating the FA31. Bottom line, I would take the numerical ratings with a huge grain of salt and use the reviews as a general guide for how people feel about a certain lens.

Very cogent points.
The fact is trying to attribute some kind of correlation between subjective quality ranking and price is fraught with flawed assumptions and potential errors.
Every lens is different and everyone has their own assessment whether it offers the most bang for the buck.

[vrrattko]

As others mentioned before....those numerical ratings aren't really a reliable source, but reading what people actually write about the lens is bit more useful. As an example when I first wrote a review for my FA77, i was totally delighted with it so I saw it as a straight 10 rating. The only comparable lens I had tried before I got 77 was Sonnar 85. But then I was lucky to own other lenses like DA70, A100/2.8, K105 and eventually I realized that all those lenses are strong performers and not much worse (if at all) than FA77 and therefore I revised my rating for FA77.
Now across the Pentax lineups you can find plenty of lenses which could chalenge limiteds, somebody mentioned K28/3.5, K35/3.5....from my own experience I can add K20/4, FA20/2.8 (I never handled DA21 so no direct comparison here but several members of this forum did the comparison and by their measures they valued older lenses better), FA50/1.7, FA35/2 and K35/3.5....
and Limiteds I had: FA31, FA77 (gone) and FA43, DA70 (those 2 I kept)

[lukulele]

Our ratings result from emotional and financial involvement, not just-the-facts-ma'am objective measurements. Ooh, it was expensive, it must be good! Ooh, it was really cheap, such a deal! But we can hopefully draw statistically significant conclusions with a large enough sample size. The fewer the reviews, the larger the grain of salt.

Rio,
Dumpster Diver philosophical directive: Cheap+deal+unusual+need fulfillment+perceived quality=Gloat
For many, the hunt is as important as the acquisition and usage of said tool.
The fact that the Pentax community offers constructive reviews affirms your grain of salt comparison.
Always enjoy your commentary.

[mikeSF]

So all lenses I got for free should have 10 in rating?
...

if you say so. i never said that.
that said, $25 for a 40 yr old helios 44-2 that requires a screwmount adapter, has old coatings, produces odd swirly bokeh at times, and may not be the sharpest lens in the box...is a no brainer must buy lens, IMO. It makes gorgeous photos, IMO. These comparisons are really THAT subjective at times. I recently spent $900+ for an FA31; you can bet if the aperture blades were not perfectly symmetrical at every stop, i'd be grumbling over that and my score would reflect it.

How would you rate the FA85/1.4? This lens is superb for portrait distance, but very poor in longer distance, and still count as must-have even it costs more than 1200 usd used.

again, the ratings will always be subjective. If i bought such a lens only for the purpose of shooting close portraits, i might love the performance and not care if it fails for tele shots. if i bought it for teles and all my experience with it were in shooting teles, well i'd likely rate it as a dog. hopefully people are reading the actual text to the reviews and not just the scores. If i see a review from someone whose work i greatly respect, their review is solid as far as i'm concerned. For example, when i see the jsherman999, peter zack, simon, axl, riorico, rparmer, etc, etc stamp of approval, that's all i need.

[macTak]

I think RioRico said a very nice bit. I'm inclined to think there is a non-objective component to lens reviews. I'm not entirely convinced it has to do with price, so much as cachet. I think highly-regarded lenses put people on a more favourable disposition to begin with (and many lenses we have to choose from are so good anyway this can make a difference in how hard we search for flaws, etc), as well as making them less inclined to go against the perceived wisdom. To me, the most interesting lens-rating case is of the 55mm Takumar and SMC-K lenses. The f1.8 and f2 models have the same optics, the only difference is an internal restriction on maximum aperture in the f2 lens (and f1.8 vs. f2 is a rather trivial difference for actual images). So, they should have about the same rating (price-wise, both are cheep and there isn't much difference to affect things). However, the scores for the f1.8 lenses are 9.33 and 9.37; whereas, the scores for the f2 lenses are 8.36 and 8.60, respectively. Perhaps, instead, it comes down to what kind of person would buy the highly regarded 55/1.8 over the less-known and regarded 55/2.

[axl]

As many others have said, numerical evaluation of lenses is very dodgy. You have to see few facts behind it, such as: what other lenses has the reviewer compared it to. For someone shooting low end FA zooms, or low end 3rd party lenses any Ltd or * lens will be straight 10. But when you start comparing them to each other you'll start seeing minute differences that may (or may not - personal choice) matter a lot.
Personally, I've tried (owned) FA31, FA43 (4 copies), FA77, DA40, DA*50-135, FA*28-70, FA*24, FA*300/4.5 and DA*55, and I've tried (only tried) DA*200 and FA*80-200.

The best bang for the buck? DA40 easily! That lens deserves as much praise as one can sing! The only "negative" is f2.8 only and that's why I sold it when I got 43. The underdog of the bunch? DA*55, with all that rubbish written about it's AF and it's price tag, this lens is often overlooked, but for certain applications it beats FA43 or FA77 with breeze. The ones I didn't care too much for: FA31 and 77. Techincally they are excellent but I never got the hang of framing with those FOVs.
The overall winner?...FA43 for me, despite selling it I keep coming back to it. It's small, fast enough for most application, delivers excellent IQ and used ones go quite cheap these days.

My 2p

[baro-nite]

ITo me, the most interesting lens-rating case is of the 55mm Takumar and SMC-K lenses. The f1.8 and f2 models have the same optics, the only difference is an internal restriction on maximum aperture in the f2 lens (and f1.8 vs. f2 is a rather trivial difference for actual images). So, they should have about the same rating (price-wise, both are cheep and there isn't much difference to affect things). However, the scores for the f1.8 lenses are 9.33 and 9.37; whereas, the scores for the f2 lenses are 8.36 and 8.60, respectively.

Given your view that f/1.8 vs. f/2 is trivial, it's no surprise you would expect the two lenses to be about the same quality/value. But I think most people have a different threshold for what constitutes a significant difference in lens speed, and I think this is just enough of a difference to matter. That said, for two lenses that share the same optical formula, I agree that the ratings difference seems exaggerated. Especially when you look at the respective ratings for the various categories -- sharpness and so on.

Perhaps, instead, it comes down to what kind of person would buy the highly regarded 55/1.8 over the less-known and regarded 55/2.

I very much doubt one could discover such "types". But this difference is intriguing. I think this is more likely a function of how pre-conceived notions affect judgment. The f/2 version was the cheaper lens in its day, so it must be inferior, right?

[Docrwm]

interesting finding and thanks for your study of this.

I actually tend to behave oppositely. when considering a lens review, i score largely based on my perceived value of the lens. That is, if there is a strong performer that only cost me $40, i am generally going to conclude that it presents a better value than perhaps a somewhat better performing lens that cost me $500. You can bet when i pay $500-$1000 for a lens i am going to be super picky about its every attribute.

I agree with that approach and use it myself. The newly added extra dimensions in the Lens Review section includes a "Value" score. I based my #'s in this thread on the older (and still the predominant) number based on one summary score for each review per lens which would include a variety of factors.

Aggregate scores across sufficient reviewers do yield meaningful results and differences. Its entirely possible to point to a single review, or a cluster, and find exceptions. However, we're talking about populations not individuals when we look at scores over 40+ reviewers across many lenses. Its like the old woman that when told that 15% of people have warts says she doesn't know anyone with a wart. Doesn't change one whit that the original statement is true and accurate. Same for subjective ratings, you just need more #s and clearer differences.

Thanks for the thoughts.

[RioRico]

(we'll see about the durability of the DA 35/2.4 plastic mount after a few years of usage)...

Have you any evidence that polycarbonate (Lexan) mounts are less durable than metal mounts?

I see many review dings of lenses with polycarbonate construction because of their build and feel, not their optics and performance. The FA100-300 (silver) is one such. Mine is over 20 years old, works like a charm, shows no mount wear -- and would probably withstand more punishment than a metal-body equivalent. I'll argue that because polycarbonate-build lenses are under-scored, they're better deals than higher-rated metal-build glass.

Polycarbonate is not polystyrene. Not all plastics are created equal. Metal dents; plastic bounces.

Always enjoy your commentary.

Thank you, thank you.

[/me humbly burnishes fingernails on sleeve]

[L33tGreg]

DA40 is pure magic. IMHO it is 2x better than the DAL35.