[AOski]

So, I'm shopping for a new lens and really like the review database here... However, I was wondering if anyone could do a quick run down of the difference in the classes of Pentax lenses. For example a FA, M, A... What's the dif?

[Pentaxor]

it's a generation of lenses. it's like PSone, PStwo and PS3

K - first generation, manual focus
M - 2nd generation, some lenses are better than the K and some aren't. some lenses are available here that aren't available in the K series and vice versa. manual focus
A - w/ auto aperture feature
F - auto-focus feature and others
FA - 2nd generation of auto-focus
FAJ - budget version of the FA series. some consider them as junk but who knows, I never tried or owned one and probably never will.
DA - recent series compatible for Pentax dSLRs. some lenses are compatible for full frame slrs.

you cant go wrong anywhere with these's generation of Pentax Lenses except maybe the FAJ series. each generation have their own share of top notch glass which are considered rare or irreplaceable or sought after. some are common but that doesn't mean that they aren't excellent.

[MrEspie]

-K and M series lenses are notable for their all-metal construction and lack of an "A" contact. What this means is, with Pentax DSLRs, you'll have to use stop-down metering mode. They are, obviously, manual focus. Longer M series lenses will usually have built-in, sliding hoods.

-A series lenses tend to be a mix of metal and some plastic construction, but are considered rugged none the less. They have the A position on the aperture ring, allowing for the full range of metering functions with most any Pentax SLR. They are also manual focus.

-F and FA series are both autofocus. There are differences in body design, but most share optical designs. I'll let someone else cover the differences here.

-FA J series lenses are inexpensive, and have all of the features of FA series lenses, less the aperture ring.

-D FA series cover the full 35mm frame, but are also coated for digital use.

-DA lenses are optimized for the APS-C size sensor on Digital and won't function properly on most Film SLRs.


That ought to be a start. As for the K, M, and A series lenses, my advice is to not let the extra work in using them scare you. In the long run, you'll learn more about photography and ultimately be stronger for using them. I hope that helps.

[SteveM]

K's and M's (and FA Ltds) have a great build quality and are nice to use. The As have some advantages on newer cameras and often (depending on the style of lens) give slightly better results due to Pentax tweeking with the design, but they feel plastic to me. My favorite older lens is a K (which doesn't say K on the ring....it juts says SMC Pentax). The Ms were made a bit smaller and sometimes fall short because of it.

[AOski]

Excellent info, as always!