[Buschmaster]

Someone told me that with the K series (K110D, K100D, and K10D) you could use any Pentax lens produced on it. Is that true? Even with film lenses?

[carpents]

You can use any K-mount lens, from the brand new digitaly-optimized DA and DFA lenses, to the autofocus F and FA lenses, the excellent manual focus A lenses, the mechanical aperture M and K lenses, and (wait for it...) with an easy adapter you can use all the pre-1970-something screw mount lenses.

The M and K lenses require you to shoot in Manual mode if you want to control the aperture. The screw mounts require you to shoot in 'stop down' mode, meaning the aperture changes as you're looking through the lens.

Other than that, no restrictions. Pretty cool, no?

Edit: This is the same on the *ist series, too. Not just the new K series.

[Buschmaster]

You can use any K-mount lens, from the brand new digitaly-optimized DA and DFA lenses, to the autofocus F and FA lenses, the excellent manual focus A lenses, the mechanical aperture M and K lenses, and (wait for it...) with an easy adapter you can use all the pre-1970-something screw mount lenses.

The M and K lenses require you to shoot in Manual mode if you want to control the aperture. The screw mounts require you to shoot in 'stop down' mode, meaning the aperture changes as you're looking through the lens.

Other than that, no restrictions. Pretty cool, no?

Edit: This is the same on the *ist series, too. Not just the new K series.

That is indeed awesome. So basically, everything will work in manual mode since 1970? And how much do those adapters run? Probably not such a big deal as i won't probably be using too many of those lenses even if I had the adapter.

[carpents]

Screw mount adapters should be anywhere from $25-40 I think. I haven't purchased one in a while, so prices could be out of whack.

I have a pair of lenses from the 50s that I can use in Aperture Priority mode, stopped down. Brilliant. I have a collection of Pentax lenses from the 50s, 60s, and 70s that I use all the time.

[Dana G]

Because I like the 70-200 range on the film cameras, I got an old K 45-125f/4 lens for my D (and now the K10D) which covers approximately the same range of field of view.

It's easy to use on either camera. Set the custom menu to Allow the aperture ring, set the green button in M mode for Tv, and you've got what amounts to a aperture priority lens in center-weighted metering mode. Press the button to take a reading, then compose and shoot. Just like the old days.

The 45-125 has focal length markings along the barrel, so you can enter the actual focal length you're set to into the shake reduction menu.

[Ivan Glisin]

See the answer here:
https://www.pentaxforums.com/forums/pentax-dslr-discussion/1313-metering-smc-....html#post9174