Heretic!

The DA18-135wr is a lens with its own polarizing filter built in!

No not as it pertains to light, but as a conversation piece.  Most owners think very well of it, and its specs hold great appeal: the first silent DC motor has held up well compared to the perceived woes of its SDM sibling, its weather resistance and range are great to carry as a single unit.  WR does not just work in foul weather, but in many other times when switching lenses isn't a great idea (think dust and sand not just rain-drops).  At the same time, most people point out edge softness as the price of a super-zoom lens, and chromatic fringing as easy to correct with either in-camera or on-computer processing.

All points are fair, and each owner needs to evaluate what it takes to make a lens do well enough for their needs.  I have tried three of the 18-135s and it doesn't work for me.  I sold my most-recent copy and picked up a Sigma 18-250mm the same afternoon, and put some money in the bank (aka 'lens fund').  The compromises required for this lens fit me better, and it's that simple.

What does the Sigma do better?  Well it has more range, clearly enough, and the f/6.3 penalty kicks in right about where the 18-135 stops so fair is fair.  I haven't really tested it explicitly at 135mm but I have the strong feeling it works better than the Pentax lens there.  Why?  Because it outperforms the Pentax at higher focal lengths for color fringing, showing essentially none in spots where the DA lens showed quite a lot.  I am not a fan of correcting lenses within the camera, which made my time with micro-43 gear trying too.  The Pentax K-5 series exacts a time penalty for correcting fringing and distortion at the time of shooting, that's mostly what I dislike.  Both my early Sigma 18-200mm and this 18-250 do not need fringing correction to speak of at any time - sure it can be done and improve things, but only when peeking at a higher level that I enjoy peeking.  Again, it's that simple to me.

I will post some teeny images here to show what I mean, but click 'em to see things better.

hmm, wires look
wire-colored...

The dreaded telephone pole/wire shot with +EV correction always outs bad fringers and the Sigma barely flinched at 250mm wide open, which beat the 18-135mm by 160mm± in my experience.  Yes I've lost out on weather resistance, but the Sigma has its HSM motor that is nearly as fast to lock focus (not quite though) and is equally silent.  OK I lost quick-shift manual focus too, and that's a bummer though not as huge as I keep telling myself it should be.  I can definitely detect fringing near the corners, and if I get worked up enough about it I can push a button on my computer.  I probably won't but I can!

250mm f/8 bottom crop 100% - soft w/minimal fringing.
The extreme corners do show more fringing.

And lest we forget, the Sigma can do closeups to 1:2.5, almost half life-size.  I tested it against my Pentax A50/2.8 macro and 1:2.5 is a very good match for scale, but let's be clear the macro prime impressively outscores the superzoom.  When closeups matter the 50 must come along, but when it's incidental to the shooting this zoom will serve well enough in good light.  Funny thing about closeup ratings, Sigma always underrates their zooms: from the 17-70 to the old 18-200 to this one, I can always squeeze out a closer closeup than they claim.  How nice!

one 'last' tweak

No kit 'tweak' is ever the last one, but knowing that I cannot be jinxed!

Well my bid for another SMC 17mm f/4 won out, so the 'fish-eye problem' is solved.  In the interim someone offered their 18-250 Sigma HSM Macro for below the price of my nice-but-not-amazing DA 18-135wr, so the former was purchased & the latter sold.

When my first da18-135 came along its optical performance at telephoto compared poorly to the Sigma 18-200, but had silent focus and WR to even the score; this improved 18-250 has the silent HSM motor, and 1:3 closeups too.  Guess I need to carry a small umbrella with it, oh well I'll manage.  And yet another 18-55wr will join me in the future.

Why pretend the kit-dealing is over?  Well it's house-dealing time instead, so funds are in voluntary lockup (again?) while that goes on.  I'm pretty happy with what I see anyway.

active status: Sigma 18-250 1:3, k17FE, a50 1:2, stk105, m200, tak300
within reach: qr28-70  out of reach: Rok8FE, a24, q28-90 1:2, q100-300
wish list? An O-GPS1, an 18-55wr.. and perhaps a faster mid-tele zoom (hmmm this 28-70/2.8-4 is pretty fast!)

salve for my disappointment

Several new Pentax products have been announced for the CP+ trade show: a 1.7x teleconverter, some medium-format updates, compact cameras (now labeled Ricoh not Pentax, as expected).  No 17-85± or 130-380± zooms - although a new 70-200± was placed on the list of future items.  I had hoped that one or two future lenses would become imminent ones.

Given no 17-85 option is forthcoming, I have picked up another copy of the DA 18-135mm f/3.5-5.6 - my third.   Recent shots in snowstorms demonstrated the value of a wider weather-friendly zoom, and since I really don't want to change lenses at ~50mm any more this is the answer for now (i.e. this coming week).  It's not that it's a poor lens, but shooting at the long end revealed color fringing beyond my tolerance, and my unwillingness to engage the in-cam corrections led to many results that left me dissatisfied.  If I stop before 100mm and stop down more at the long end, this should be satisfactory.


I have felt that the 18-135 lens has been overpriced since its inception, but this used copy was 'properly' priced at about 3x the 18-55WR.  Quiet, WR and good range; just remember to go to f/8 above 80mm and you'll love it, I keep telling myself.  It's the doing that matters though!

a month's trials and a fine hike

I took a pretty walk early in October, trying out several lenses in turn.  The bag carried the DA18-135 for simplicity, plus a Sigma 15 fisheye, Rikenon 28 and the DA40.  The Sigma 50 stayed in the car, victimized yet again by the DA40.  Sadly the Promaster 100 macro stayed at home; it would have been a fine complement to the other primes.  Also sadly, the 49-52mm step ring did not come, so the DA40 had no polarizer like the 28 and 18-135.  While I'm filled with regrets, the Rikenon 70-150 f/4 really should have been there too!

At first the 18-135 got all the shots and I found it satisfactory - especially since it was my only 'telephoto' option! - but weather conditions were perfect at the time, so its weather sealing was of no value here.  No need for silent focus either, as I was essentially alone and 6500 feet up!  So after taking a shot at  around 40mm I popped on the Limited prime and enjoyed it for a while.  The smaller camera/lens combo was most pleasant!  It alternated with the all-manual Rikenon at times, which with the cPL filter took several powerful images.  I must say that overall I preferred the primes as my way to shoot.  Having fairly large FL gaps is not big to me, and 15-28-40 felt just fine; I would like to add the DA70 some day to fill the space to the 100, but I also have a Rikenon 70-150 zoom that would have served very well - sadly it also stayed home. 

At the turnaround point on my hike I broke out the 15mm fisheye, and it was great fun.  Starpoints made the sun into an artistic light source, and the larch and huckleberry shrubs were great color features.  I'm always impressed that the sun can be in an image yet exposure doesn't overcompensate with a black foreground!  Soon the 15mm went back in the pack, and the DA40 was back on.  The 40 and 28 got plenty of use on the way back.

So what did I learn?  (And will it stick?)
I think the 18-55WR is enough WR range for my purposes, and the $300 saved can go back in the fund for a DA70.  I will need to try that 70-150 f/4 with the other two primes first however - as the Rikenon 28 makes the DA21 less vital to my plans, the 70-150 may restrain my 'need' for the DA70.  I'm still on the fence for a macro, with two fine choices: the Sigma 50/2.8 EX DG has been sidelined by the DA40 and the Promaster 100/3.5 lost its chance to shine this trip.  So a few more tests to winnow the set are needed.

More shots from this trip on Picasa!

trying again

About a year and a half ago, I wrote this about the Pentax DA18-135WR lens, which was supposed to be my best answer to the kit-lens replacement conundrum.  I had tried replacing the kit with several different lenses (DA16-45 and Sigmas 17-70 18-200 and 18-50 f/2.8-4.5) but this one had the best feature set of them all.

The DA18-135 was pretty new at the time, and I got mine via a swap.. which meant that I had no receipt on which to rely if the lens had issues.  It did: I could not bear to look at the results beyond about 70mm.  I let it go to another owner instead of making Pentax aware of it, and let my frustration be known; nearly every reply told me that lens was a bad copy that should have been sent off for inspection.  A couple of reviews online were not favorable, with flaws similar to what I found - but most reports are that it beats the 18-55 in its range plus does well at longer FLs as well.  I have felt bad ever since about not getting it repaired, since it was too new to be beyond any sort of warranty.  Too late.

Even with my bad experience, the features remain tantalizing.  If you need WR you are best served by not switching lenses, even from one WR to another.  And the silent focusing of the DC motor pairs well with the K-7 and K-5 with their soft shutter sound.  So once again, the 18-135 sounds like an ideal lens!

So I'm trying again, having won a bid on a copy removed from someone's new K30 kit.  (Guess the seller has the coveted 16-50 and 50-135 DA*, or something else to make this surplus to his/her needs.)  I sure hope this one meets my standards, but if not I will send it in to be inspected regardless of any proof of purchase.  I would love to wander with this lens and either the DA55-300 or the SMC-M 200/4 for longer work, and my two Sigmas (15mm fisheye and 50mm macro) available off the bench.

Update - this is undoubtedly a better copy of the 18-135.  Sharpness is decent, but more important is the lesser degree of color fringing at telephoto focal lengths.  Yes I can make it look bad if I try and if I look hard, but that's nothing compared to the old copy.  This of course shakes up the kit again - off with the 18-55WR and whatever else can bring in spare funds.