do I always root for underdogs?

It's a curious thing.  I finally pick up a really nice lens, then begin speculating about the next one.  I'll consider many factors, some which strike the average shooter as mildly to wildly irrelevant - and then overlook the most popular option while straining to find that ideal-for-me lens.

My Next Lens should be a very good wide-normal zoom lens that doesn't weigh a ton but fits nicely with the DA* 50-135mm.   I'm in no rush as I own the DA 18-55.. but many 'better' options exist.  Four 17-70 models, several third-party 18-50s and fast 17-50 f/2.8s, the old reliable DA16-45 and the new wide-ranging DA16-85 make the list alongside the DA* 16-50 and LimiZoom 20-40.  The Sigmas are odd in that half of them zoom in clockwise while the other half switch directions - so it would be nice to find one that turns the same way as the DA* (that knocks the list down a bit).  And hey why not use 67mm filters like the DA* as well?  That narrows the field to just a few.

image from dxomark.com

Oddly enough, one of the remaining items is a lens that has received constant praise for at least five years: Tamron's 17-50 f/2.8.  I've tried everything I can afford in that range except this lens (and the newer Sigma 17-50 that zooms 'backwards').  I've read about the excellent image quality, the field curvature that affects wide shots at fast apertures, the fact that over half the owners use the term 'workhorse' - yet I always grabbed another DA16-45 or 18-55 when the need arose.

The Tamrons are now below $250 fairly often on the used market, just above the DA16-45.  It has every feature I'd like except weather seals: range, speed, price, even matching zoom twist!  It does not have silent focus like the Sigma HSM and the DA*16-50 HSM, or the DC-motorized 20-40Ltd or 18-50RE.. bummer.  Is it worth paying quite a bit more for the first two, or essentially matching the 18-55wr for more money?

EDIT/ P.S. -  and the very next day reconditioned Pentax 17-70 lenses dropped to $230ish.  That too is a curious thing -- and one that blows all previous analyses to pieces.  I sorta liked the DA17-70 with its range, fixed f/4  and 67mm filters.  I didn't like three things: SDM only (which is bad if he ever-maligned SDM were to fail), no weather seals, and close to $500 so outgunned by Sigma 17-70s and the Tamron 17-50.  Until it's not!

image & review via
PentaxForums.com

So the 20-40WR is about 3x this price, the Sigmas 2x and only the Tamron (used)  can stay with it - less range but f/2.8 speed.  Thanks to the well-noted SDM fears the DA17-70 might even be the ultimate underdog of this lens type!  It's the lowest-rated DA zoom at PKForums other than the almost-free original version of the kit 18-55, mostly for SDM and other focus breakdowns.  

Two questions remain: did their reconditioning solve anything SDM-wise, we wonders?  And is $230 too much for a manual-focus lens not labeled "Samyang"?

Decisions suck.

shooting star

DA* 50-135mm f/2.8

DA-star, that is.  My first star has arrived - likely my only one for some time, though times change.

The * lenses are Pentax' headline, pro-caliber lenses; DA* for aps-c sensors while FA* is for 36×24 types.  The 50-135mm f/2.8 arrived yesterday, but it came to the house while were were away - so I've just picked it up today.  I parked across the street from the Post Office at the central Longview city park for a few tests against the 55-300mm set at 55 and 100mm and f/4.  I have not compared the images yet, but images from the DA* have an oh-my factor that cannot be ignored.  Images do indeed look 'primal' even if just on the K-r rear screen at moderate zoom.  The DAL 55-300 is no slouch optically so side-by-side checks will be fun.

As to mass, the 50-135 is a fairly bulky lens, similar in length to the 55-300 but considerably thicker and more dense.  Larger and more pieces of glass will do that.  It's not so bad that it will stay behind on hikes, but it does have that 55-300 to compete with!  The lack of WR on my copy of the latter does suggest that the DA* is a fine choice for outdoor travels despite the extra 350 grams.

The real DA* benefit comes from this lens taking over the duties of all primes in the 50-135mm range, which is why the M85/2, M100/2.8, A100/4 macro and M150/3.5 have left the building (or will soon).  The A50/2 and M135/3.5 have no resale value (they go for $20-30 on most sites) so they will keep the K24/2.8 company in the classic-prime box.  One from each generation, how nice!

I'm contemplating a future where a 1.5x teleconverter makes this a longer f/4 lens; probably not the worst idea I've had.  Not yet though!!