Old lenses

I'm considering dumping my Canon DSLR's and going back to Pentax, after using Pentax for years, back in the good old days of slide film. I still have my old MZ5-n body and the 3 Sigma lenses, that I used on it, purchased in the late 90's. Will these lenses work on the current range of Pentax DSLRs? The lenses are; 135-400mm F4.5-5.6 APO SerNo. 1018180, 100-300mm F4.5-6.7 APO SerNo. 1076885, and 28-80mm APO SerNo. 1190192. I have tried in vain to find someone local who has a Pentax DSLR, to try the lenses on, but I can't find anyone through my contacts who has one. Going through related topics on this site has not really heped, except that all the lenses have the A (auto?) marking at the smallest aperture setting on the aperture ring. Any help would be greatly appreciated.

Thanks
Danny

All the old lenses I've used with an A setting have worked on the GX10 (K10d), GX20 and K-7. Manual focus but will work exposure through the dials.

Unfortunately for precise accuracy you'll probably have to wait for a member with a match for your lenses to confirm the body they use it on and the modes it works with.

You'll be a celebrity if you do re-fect? (what is re-defecting?)

You might find a member near you? Maybe a shop would let you try a body on your lenses? (SRS comes to mind).

Without looking up the lenses in question I cant be specific, but heres some K mount facts:

K mount: manual lenses, no electrical contacts. These will workd but with limitations to the cameras functions.

KA mount: non-AF lenses but with electrical contacts. These will be more or less fully compatable with any Pentax DSLR with the exception (obviously) of auto focus, some I think may be limited to centre weighted metering.

Any later mounts, KAF etc will work with all features on the camera.

Just a quick edit: I notice your body was the MZ5n, if your lenses are aouto focus they will work perfectly on any DSLR

Providing that the lenses are Autofocus then they'll all work just as the new DA lenses do, just remember to set the aperture to "A".

All Pentax lenses will fit their DSLRs, although there are various limitations with the older glass. For example, PK-A lenses will work with all exposure modes but only focus manually, the earlier SMC Pentax and Pentax-M lenses will be manual focus and need stop-down metering. You can even use the M42 mount Takumars with an adapter.

Where are you located :
Would be happy to let you try your glass on my K20 in Chester or Wrexham, or within reasionable driving distance. Alternatively can send you an old but good film camera for you to play with.Cost would be £5.00 to charity. If interested say here and i will PM you a contact number.
Davex.

Dave, OP needs DSLR "I still have my old MZ5-n body".

Lobster if you post your location you might find a Pentax fa*iry living near by.

Am a bit slow on uptake tonight the offer to try them on my K20 still stands though.
Still a newcomer, but presumably the mount is the same :, if they are af, which I doubt, I do have a few af film cameras I would be happy to post to a good home to be used for testing.
Davex

Not counting the Auto110, Pentax haven't changed their mount since the 70s

If he bought the lenses with an MZ5 they are almost certainly Autofocus and as such will work with any Pentax SLR or DSLR he cares to mount them on.

The specs sound like they're probably Sigma lenses as opposed to Pentax originals (not aware of Pentax ever having made a 135-400 or used the abbreviation APO), but that shouldn't make a difference. If they fit and work on an MZ-5n they should work just as well if not better on a Pentax DSLR.

In the original post he states they are Sigma.

I've got the 135-400mm F4.5-5.6 APO Sigma and it works OK on digital.
Even the Exif data gets picked up (on a lot of lense it doesn't).

PhotMe identifies the exif as:

SIGMA 135-400mm 4.5-5.6 APO (or SIGMA 170-500mm F5-6.3 Aspherical RF APO)

which is OK, it rarely id's just as one lens.

Firstly, welcome Danny to the forum. I hope you do come back to the Pentax fold. This is a friendly place to talk about all things Pentax, though some discussions do become heated.(always resolved with a cuddle...)
Secondly, it's always handy if new members add their location, so that others in their area can offer some local knowledge/assistance/whatever.
You might find there's someone near you who can answer all your questions.
Regards

Still waiting for my cuddles!!!!
Thoramay.

The beauty of the K mount is the fact that ANY lens can still be used on the latest, in fact all, DSLRs from Pentax.

There are some limitations, as has been pointed out, but that apart,you'll have no problems a question here won't solve.

So go out and get yourself a new Pentax DSLR, they tell me the K7 is a good bit of kit so...

Thanks for the help folks. Sorry if I was unclear, the lenses are all Sigma, and I live in the Scottish Border Region. I did look into this a few years ago, and asked two shops if I could try the lenses on a camera to see if they would work. For some reason they declined my request, and needless to say neither, received my custom. One was Jessops and the other an independant retailer.

dougf8, redefect, dedefect, who knows. Having started out on Praktica's back in the 70's moving onto the Pentax ME super(remember them)in the early 80's, I went through 4 of them, using them till they fell to bits (not a reflection on Pentax quality, more my rugged outdoor use of them). Finally got the MZ5 late 90's to move into the AF age, as I was having trouble trying to focus manualy.

God knows why I went for Canon Digi's, but within a few years I missed my old Pentax. My Sigma 170-500mm lens is knackered, and it's either fork out for a new 120-400mm to fit the Canon, or a new Pentax body and my old lenses, and I would rather spend the cash on a new Pentax body if the old lenses will work on it.

It was perfectly clear to me that they are Sigma lenses.