This matter has been touched on by others before, but I believe it may be beneficial to re-examine it by a different approach. I put together some of the salient info/evidence that we have concerning three well-known Pentax lenses, presenting them as actual case studies, as it were. The idea is to allow the reader to easily correlate the data, do some analysis and come to some conclusions.
I do this mainly for the following four categories of people:
a) There may be some users of Pentax lenses who after reading online reviews of their lenses come away feeling perplexed and underwhelmed, now doubting their lenses and wondering if perhaps they made a wrong purchasing decision
b) There may be some who feel a certain sense of injustice at how Pentax lenses are being misrepresented in a negative way by some online lens reviews
c) There may be prospective buyers of Pentax lenses who have received good recommendations from trusted friends using Pentax glass, having also been well impressed after seeing pictures taken using those lenses, but after reading online reviews now feel not so sure
d) There could be people planning to change systems entirely (wishing to enter Pentax), or others just starting off and wanting to build up a Pentax system, who are impressed with the Pentax bodies; but having read online lens reviews of Pentax glass come away with a general impression that these are somewhat sub-par in their performance. In categories (c) and (d), it would be a shame if they subsequently turned away from a lens(es) which potentially could have given them many years of enjoyment
e) You may be able to think of other categories
In each of the case studies below you will detect a
clear disconnect - something just doesn't add up when comparing the verdict given via technical testing versus what is being experienced in real-world usage.
Case 1: FA77 f1.8 Limited
This famous Pentax lens received an unremarkable 3.5/5 stars from Photozone (PZ) in terms of optical performance. PZ went on to conclude that
"Optically it doesn't offer much beyond the mainstream in this class but don't misunderstand this as something negative because moderate fix-focal length tele lenses tend to be great performers." PZ also questioned the high asking price.
In short, PZ does not view this lens as particularly remarkable.
And yet, users of the FA77 worldwide know for a simple fact that this is a one-of-a-kind lens - a lens capable of producing pictures of exquisite beauty, rendering subjects with remarkable vividness and lending a magical, classy "polish" to the overall image difficult to obtain otherwise. Indeed as a portrait lens it is widely regarded by many Pentaxians as having practically no equal, period.
What is remarkable - and scary - is that the PZ review seems to not have detected any of the above traits, so highly prized by those who know the lens well. No wonder then that PZ questions the asking price - but we know that in life, a tool
this remarkable will naturally cost more. Certainly the sample photos included in the PZ review do not exhibit the traits just described.
And while PZ cannot see anything particlularly outstanding about this lens, on the other hand we have Michael Johnston from Luminous Landscape in 2002 calling this lens
"the best autofocus lens in the world".
Hence we see a clear disconnect somewhere.
Case 2: DA35 Macro f2.8 Limited
PZ declares that this lens
"does not excel".
Yet Michael Johnston in reviewing this lens in 2008 concludes that
"It ranks right up there with the best lenses I’ve ever used in any format." An Optical Paragon - photo.net
Some might conclude that Johnston is really nothing more than a Pentax-fan, and this biases his judgment. Granted. But it would be equally valid to propose that here is a man with deep and varied photographic experience, with access to various lenses from diverse manufacturers - including the best and costliest - and moving on from 2002 to 2008 has found another lens worth writing home about; and it just happens to be another Pentax. Thus it is not necessarily correct to conclude that he is merely "pro-Pentax."
Further, if you click on the link you will note that the review was actually
co-written with Carl Weese, another experienced photographer. In fact, both of them are actually "trading notes", sharing what they have independently discovered after having used the DA35 Limited for some period of time. Like Michael, Carl is equally blown away. So this is clearly no "pro-Pentax" party here. What we're seeing is real-world photographers, putting a lens to real-world usage, and learning (over time) its capabilities and character, with
both coming away thoroughly impressed.
As a matter of fact, Weese's methodology for "testing" a lens is particularly enlightening - he states:
"My “tests” really consist of heading out the door to use a new piece of equipment for the kinds of pictures I like to make, and then see how it does. If I run into something that looks like a problem—say obvious barrel distortion or color fringing—I’ll run a specific test to nail down that issue. For the most part I don’t do tests that aren’t really just attempts to make pictures."
This says a lot! Test charts are all fine and good, but there is a
very real need to thoroughly evaluate a lens under real world picture-taking situations. Indeed, the only instance where we could legitimately say that technical tests
alone are adequate is when we have bought a lens
solely for taking pictures of test charts - which nobody does of course!
So again, a disconnect is apparent between lab tests and real-world findings.
Case 3: FA43 f1.9 Limited
This lens has been tested twice by PZ, and the amount of controversy generated has been considerable. Bottomline, PZ is
"still not impressed by this lens".
It is not my intention to get into all that here, but note that Lenstip, another online lens test site, is even more thorough than PZ, going into things like astigmatism, light transmission and coma (the latter yielding a very bad result).
Yet neither PZ nor Lenstip seem to be aware (certainly they do not mention it) that the designer of this lens, Jun Hirakawa, had very clear design intentions when creating this lens, and one of the things he did for example was to
deliberately leave certain optical parameters only partially corrected in particular axes.
One cannot help but wonder if such design decisions are at least partially responsible for the lens' "poor showing" in test-charts, yet creating absolutely
stunning images in real-life usage!
Again, the test pictures in PZ and Lenstip do little to showcase what this lens is truly capable of. Users familiar with this lens know it to have stunning colour rendition, an almost startling "3-D" rendering of subjects, and micro-contrast of the highest order - among many other virtues relevant to picture-taking. Yet these aspects are hardly if at all mentioned in most technical reviews, let alone measured quantitatively!
Interestingly enough, Steve Huff evaluates this lens - and he does so by way of actual real-world usage - and comes away impressed.
The Pentax K5 Digital Camera Review | STEVE HUFF PHOTOS
All of this is not to say that the FA43 Limited is in anyway a "soft" lens - by f2.8 it is certainly very sharp, rising to nearly insane levels at f4.0. I do not need to measure my copy of this lens to verify it - I see it plainly evident in my pictures taken!
But that's the whole point isn't it? A lens is so much more than just sharpness alone! As Carl Weese put it in his review of the DA35 Limited:
"Once we pass a certain threshold of “sharp enough,” though, sheer resolution isn’t anywhere near as interesting as other aspects of lens performance."
I believe that the more we stop obssessing about
sharpness per se, and look instead into other aspects of a lens' character and rendering, the richer and deeper will be our appreciation of the pictures taken.
Indeed looking at some of the older B&W pictures taken back in the days of manual-focus lenses, it becomes apparent that some of the shots weren't even perfectly in focus - so much for sharpness! And yet many of these pictures have tons of character, and really "speak"!
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And so we conclude. If as a reader you find yourself in any of the categories of people mentioned at the beginning, know for sure that technical testing of a lens has its rightful time and place, but user experience is
every bit as weighty, and often more
relevant, since the latter is born out of real-world photo-taking situations.
We could easily go on forming more case studies, but I judge three as being quite adequate. And the fact that all three examples given are
Limited lenses - Pentax's premium glass - makes it all the more alarming, for it would appear that several reputable lens review sites seem quite unable in their testing to capture the heart and soul - the very magical essence - that makes these lenses so very highly regarded and prized worldwide!
To put it quite simply, technical lens tests have their usefulness, but they certainly
cannot give us the full picture - pun intended!