Anyone use these lenses? I believe they are SMC K mount. Fairly modern and more compact than older pentax lenses. I'm interested in the 135/3.5 as a small travel lens.

That should make a really good small travel lens. The IQ is supposed to be good, even wide open. Pentax has always made interesting glass.

I am not sure if its considered a forum violation to point users to other forums, but this might be worth checking out.
Lots of Pentax fans here: http://www.pentaxforums.com/forums/pentax-slr-lens-discussion/

The SMC Pentax-M 135/3.5 is a fine little lens. You have to remove the aperture control lever and lever shield to mount it on a 5D, but it works very well (I have one that I occasionally use for travel). There are many other fine -K, -M and -A lenses (the -K doesn't actually appear on the name, that’s the original "SMC Pentax" series), and the lineup includes some of the best glass available, period. The best place to learn more about the Pentax lineup is at Boz Dimitrov's K-mount site: http://www.bdimitrov.de/kmp/ His WWW page includes links to many Pentax resources, including a number of Pentax lens review and test sites. One of the most valuable links, called "BOA's Gallery" is no longer available online, but I downloaded its content many years ago and I'd be happy to send you a copy.

For the price of entry you might want to look at the slightly older Takumars as well. The advantage here is that they can be found cheaply (but prices have risen), they adapt with a screw on adapter (no lens surgery) and they have a auto aperture switch which is very handy with stopped down metering.

The Taks also have a great feel and are very well made. I have always been a big fan of Pentax glass. Its worthy of study to keep certain "star" lenses on your radar should you come across a good copy for a bargain price...

dcmiller wrote:
Anyone use these lenses? I believe they are SMC K mount. Fairly modern and more compact than older pentax lenses. I'm interested in the 135/3.5 as a small travel lens.

I had it, used with Pentax film camera, very compact, very good lens, with built-in hood. Pentax-M 135/3,5 and Pentax-K 135/3,5 optically are very similar but K vercion is very rare and does not have buil hood. SMC Pentax-K 135/2,5 is much better (!!!Not Takumar-A(Bayonet) 135/2,5) ...mmm, but larger

Unfortunately all Pentax lenses needs "surgical" procedure before installing to Canon EOS. I could not do it with my favourite lenses so I sold them all.

http://www.takinami.com/yoshihiko/photo/lens_test/pentax_tele.html

http://stans-photography.info/

I also bought a Jena and sonnar to compare. All these were under $100 so I don't mind doing some surgery. I will lso buy an SMC TAK when I find the right price and quality.

Some of the M's are superb (200/4, 135/3.5) some are average (28/2.8, 50/2) some are every bit as good as their non-M brethren (300*, 50/1.4)

Older M and K lenses may well be the best bargains in Pentax glass as they're less desirable than the later A lenses (which have full function on Pentax DSLR's) and less adaptable than the earlier M42 Takumars.

Keep an eye on the Pentax 28 f3.5 shift. It is a K lens not M but the prices lately are quite affordable. BTW forget about the buy it now prices on ebay for this lens, you can find it quite cheaper on auctions.

Javier Munoz wrote:
Keep an eye on the Pentax 28 f3.5 shift. It is a K lens not M but the prices lately are quite affordable. BTW forget about the buy it now prices on ebay for this lens, you can find it quite cheaper on auctions.

I've seen it several times looking at Pentax, but I have no use for just shift. Tilt I can use.