I have just purchased a K5 and some new lenses. However I have Pentax LX that I bought in 1982 and have K mount lenses for that camera.

If I ever need to, can I use the old lenses on the K5 and if so how do I set up the camera re exposure (do I put it ont automatic?).

Will the exposure be on full aperture or will I manually stop down after taking an exposure eading?

I'd be grateful for your advice.

Many thanks
David Jackson

[kanzlr]

focus to manual, camera to M mode, use the green button to measure exposure.

[ilan]

See the following link: https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...ml#post1140019

[baro-nite]

Ditto to the above, and also keep in mind that many forum members regularly use the full range of K-mount (and M42 screwmount, with an adapter) lenses on Pentax DSLRs. Not because we need to, but because we want to. Which is to say, given that you already have a collection of older lenses, learning to use them on the K-5 is highly recommended.

And if you decide you don't want to keep any of your old lenses, you're likely to find plenty of willing buyers in the forum marketplace!

[RioRico]

Ditto also on all the above. Old lenses can and should be used on your new dSLR.

I got my K20D just 3.4 years ago, with 3 new AF lenses. I now have about 220 more lenses and have sold yet another 110 to help pay for the keepers. (I deal lenses on eBay.) Beyond those first three, I can think of 4 others that I bought new or NIB. All the rest are used, mostly cheap old manual-focus prime lenses; many are superb. Just 12 are autofocus. About 60 are PK bayonet mount. The rest require an adapter or modification, to stick the lens onto my camera. And they all work just fine! (Well, all except a few Super-8 and CCTV lenses that will have to await a different camera.)

Your LX lenses will be pretty easy to use on your new K5. The link that ilan provided tells how. Don't sweat it. Have fun!

[interested_observer]

Evening David,

Welcome to the Forum. I have actually purchased 2 old Carl Zeiss lenses and converted the C/Y mount to the K mount, so that they are just plain old K bayonet mount lenses. They work wonderfully, so as Rico observed - it is very worth wild to use old quality glass on the new digital camera bodies. I also have two old M42 lenses (one I purchased while in the Navy in 1970) and also an old K shift lens. They all work very well.

I have an almost 3 year old K20 and it works wonderfully....

[koregano]

The Pentax forums are by far the best in the world. I can always find info that is relevant to what I am looking for. I just bought an old K-1000 and it came with 6 lenses, most of which are older. Some of the lenses are actual Pentax lenses, but a few are off-brand. There is even a Canon lens. They are all K-mount lenses, but when I put some of them on I am getting the F-- on my K-5. So I have 2 questions:
1. Can using any of these lenses damage my K-5?
2. What am I not doing that is keeping some of these lenses from working? I have it on manual mode and manual focus is on.

Thanks

EDIT--ok so the above link from ilan gave me some good info. I get why they aren't working.

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Last edited by koregano; 02-20-2012 at 08:50 AM. Reason: found answer

[baro-nite]

Some of the lenses are actual Pentax lenses, but a few are off-brand. There is even a Canon lens. They are all K-mount lenses, but when I put some of them on I am getting the F-- on my K-5. So I have 2 questions:
1. Can using any of these lenses damage my K-5?
2. What am I not doing that is keeping some of these lenses from working? I have it on manual mode and manual focus is on.

I can't say about the Canon lens; I've never heard of a Canon lens adapted to K-mount. One thing to watch for is KR mount, or Ricoh mount, because of the "Ricoh pin" that happens to be in the same place as the autofocus linkage in AF Pentax cameras. The F-- aperture reading is what you get when using a plain K-mount lens (e.g., any lens labeled "SMC Pentax" or "SMC Pentax-M") on a Pentax DSLR (see "crippled mount" for more info). You have to set the aperture manually, using the aperture ring on the lens itself.

If you have a KA-mount lens (e.g., "SMC Pentax-A" or more recent), make sure you set the camera's setting to allow the "A" setting -- by default this is disabled.

[boriscleto]

The Pentax forums are by far the best in the world. I can always find info that is relevant to what I am looking for. I just bought an old K-1000 and it came with 6 lenses, most of which are older. Some of the lenses are actual Pentax lenses, but a few are off-brand. There is even a Canon lens. They are all K-mount lenses, but when I put some of them on I am getting the F-- on my K-5. So I have 2 questions:
1. Can using any of these lenses damage my K-5?
2. What am I not doing that is keeping some of these lenses from working? I have it on manual mode and manual focus is on.

Thanks

EDIT--ok so the above link from ilan gave me some good info. I get why they aren't working.

The old Canon FD can be adapted to Pentax with an optically corrected adapter (about $30). The converter acts as a short tele-converter and there is a loss of IQ, especially wide open. Canon EOS lenses can not be adapted.

It's not worth it for wide angle (a 28mm lens becomes a 60mm equivalent). It might be worth it for long telephotos.