Bump. Open to offers.

Great shame to see this camera not getting used!

I periodically run my SDM lenses to 'exercise' them, and everything has been fine...until today!

I put my 50-135 on my K5II, and it wouldn't focus! My 17-70 and 300 would, as did my new DC 16-85.

Oh ********! I thought. Classic SDM failure, but...

With nothing to lose I tried the 50-135 again. Worked! Then I noticed that it would focus from far to near, but not near to far.

Odd!

Tried the 50-135 on my KS1 and K20D. Focussed first time, every time, far to near, near to far, continuous AF - all perfect!

Must be contacts. Cleaned them on the body and lens (wiped with paper hanky) .

Tried lens again. No difference. Still not playing nicely. Tried other SDM lenses on K5II - perfect.

So, whilst it seems like the answer is 'SDM', I've never read anything that describes symptoms like mine.

To recap, the lens will focus perfectly on two out of three bodies, but only far to near on my K5II. All other SDM and DC lenses operate perfectly on the K5II.

Suggestions anyone please?

2016 bump.

I echo the praise for this publication Nigel, and if you do write a 3rd edition, I can loan you a AF160FC if you want 'hands on' and feel that it might be useful? Please PM if interested.

Bump. £175 inc. UK RMSD anyone?

Gaming meece have very fine control, and wireless could suffer from lag, so if it's control you want then it's another wired gaming mouse I'm afraid!

The 17-70 is not prone to SDM failure, that 'honour' goes to the 16-50 and 50-135, but only early copies judging by the significant reduction in SDM failure complaints posted in the various Pentax forums. Like any complex equipment, stuff occasionally happens.

It seems that there might be a connection between SDM failures and lack of use. I exercise all my SDM lenses every couple of weeks regardless of whether they've been used in the intervening period, and done have missed a beat, nor exhibited any of the reported pre-failure symptoms

What is rarely heard is how many SDM lenses don't fail.

PM sent. You will be able to reply to me via PM too.

And another bump. Open to offers!

I think there's still a chance it's the 17-70.

When the 18-55 is fitted the camera 'sees' it. When the 17-70 is fitted, it doesn't 'see' it. When there's no lens fitted, there's nothing to 'see'.

The fact that you get the same error message with either the 17-70 or no lens fitted indicates the camera is not 'seeing' the 17-70.

Check the contacts again. make sure none are stuck 'in'.

If you look at the lens mount end of the 17-70, you should see 6 little protruding spring-loaded contacts. With the contacts at the bottom, just above and to their left, on the matt black baffle, you should see two flat gold coloured contacts. Make sure the spring-loaded contacts and the flat gold coloured ones are clean.

Looking at the camera, with the lens mount towards you, and counting clockwise from the first protruding contact there should be 7 in total, number 5 being flush with lens mount whilst the other 6 protrude.

Just inside the camera body, to the right of the first protruding pin, you should see two, protruding, gold coloured spring loaded contacts.

If all the contacts look ok, and are clean, it is more likely a problem with the 17-70. You'll need to try another SDM lens on your KS1, or the 17-70 on another Pentax DSLR to determine if it is the lens that's faulty.