[Sandy Hancock]

I'm in the early stages of that. I intend to push it as hard as I can for as long as I can.

Good luck with that! Let's see how you feel in nine years time; I reckon Norm is travelling pretty well

Get the fifty!

I have both, and they're both terrific. However: the 55 has SDM motor for autofocus, these things are notoriously susceptible of failure, and mine has failed twice - and the last time it came back from Japan, it was no longer sharp, and the autofocus was slow as black molasses going uphill in January. Neither can that lens be adapted for use with screw-drive. That thing has cost a lot of time, trouble, and money, and I wouldn't buy another one. I'm still waiting for it to come back, now, as it happens, after about a month or so since I saw it last. And, even though the problem is a design/manufacturing defect that was present during the one year that Ricoh promised the thing would be defect free, they don't cover it under warranty - it costs about four hundred bucks on top of the very expensive purchase price to get Ricoh to correct the problem they created. (By comparison, I sent a camera that I'd poured hot tea on, while it was wearing only a non-WR body-cap, off to Canon less than a week ago and got it back in perfect condition yesterday.)
By the way, that 55 was my favorite lens for the KP, and that's the only reason I was willing to pay money to have it repaired - came close to throwing it in the dumpster.

[jslifoaw]

Get the fifty!

I have both, and they're both terrific. However: the 55 has SDM motor for autofocus, these things are notoriously susceptible of failure, and mine has failed twice - and the last time it came back from Japan, it was no longer sharp, and the autofocus was slow as black molasses going uphill in January. Neither can that lens be adapted for use with screw-drive. That thing has cost a lot of time, trouble, and money, and I wouldn't buy another one. I'm still waiting for it to come back, now, as it happens, after about a month or so since I saw it last. And, even though the problem is a design/manufacturing defect that was present during the one year that Ricoh promised the thing would be defect free, they don't cover it under warranty - it costs about four hundred bucks on top of the very expensive purchase price to get Ricoh to correct the problem they created. (By comparison, I sent a camera that I'd poured hot tea on, while it was wearing only a non-WR body-cap, off to Canon less than a week ago and got it back in perfect condition yesterday.)
By the way, that 55 was my favorite lens for the KP, and that's the only reason I was willing to pay money to have it repaired - came close to throwing it in the dumpster.

We all tend to remember our poor experiences. My DA*55's SDM is half dead, but can be woken up. That makes me highly reluctant to recommend it. On the other hand, I feel no such sentiments about my 60-250 or 50-135, while others whose SDM died on those lenses will likely feel the same way about those as we do about our 55s (the 50-135 can be converted but the 60-250 cannot).

If the 55 had a better motor, it has many good qualities like being relatively compact, AW, and QS. The 50 targets the best optical quality, AF, and mechanics, with price and size left in the balance.

However, I'm also often willing and able to carry 15-20lbs of gear for when it matters. Otherwise, I'll live with a good quality standard zoom (about 3-4lbs incl body), and failing that, a good smartphone + adaptable scope (1lb).

Impressively, Pentax actually provides solid choices in all these categories (including the smartphone scope).

[sebberry]

Get the fifty!

I have both, and they're both terrific. However: the 55 has SDM motor for autofocus, these things are notoriously susceptible of failure, and mine has failed twice - and the last time it came back from Japan, it was no longer sharp, and the autofocus was slow as black molasses going uphill in January. Neither can that lens be adapted for use with screw-drive. That thing has cost a lot of time, trouble, and money, and I wouldn't buy another one. I'm still waiting for it to come back, now, as it happens, after about a month or so since I saw it last. And, even though the problem is a design/manufacturing defect that was present during the one year that Ricoh promised the thing would be defect free, they don't cover it under warranty - it costs about four hundred bucks on top of the very expensive purchase price to get Ricoh to correct the problem they created. (By comparison, I sent a camera that I'd poured hot tea on, while it was wearing only a non-WR body-cap, off to Canon less than a week ago and got it back in perfect condition yesterday.)
By the way, that 55 was my favorite lens for the KP, and that's the only reason I was willing to pay money to have it repaired - came close to throwing it in the dumpster.

I have a love-hate relationship with my 50-135. It's crossed the country more times to get the focus motor replaced than I ever have, and I'd not be surprised if it took a bump along the way as it's disappointingly un-sharp at 2.8 now. Spending money on old Pentax SDM isn't something I'm really open for. Come to think of it, they should have scrapped the SDM name for the newer lenses to avoid any confusion.

[normhead]

Oh and just for clarity, when I said I shoot stopped down, I wasn't talking ƒ8, I was talking ƒ2-ƒ4 for many shots. If it had been a ƒ2 lens I'd still have all but one or two of the images I've taken with it. To me, the big advantage to ƒ1.4 is focussing in low light, and that's always on line. I tried shooting ƒ1.4, I didn't like the images...


However that is my one of maybe 5 ƒ1.4 keepers taken with the lens, and they were test shots.
Another one...


At ƒ4 (normally as low as I go...



And at ƒ5.6


Even I'm willing to admit, that bokeh is a little squirrelly, (sorry for the technical language) the DFA 50 1.4 would have almost certainly have done better. But if you can manages the out of focus areas, Bob's your uncle.

In any case, that should show you what you'd be dealing with.

Meanwhile at ƒ8.... it's fantastic