[volosong]

Uugh! SDM Fixed by C.R.I.S. three years ago, minus a month. SDM failed again. If the optical quality of this lens wasn't so great, I'd sell the stupid thing.

[KDAFA]

Uugh! SDM Fixed by C.R.I.S. three years ago, minus a month. SDM failed again. If the optical quality of this lens wasn't so great, I'd sell the stupid thing.

I can understand your terrible dilemma. :-( The 50-135 is indeed utterly outstanding, image-wise. But SDM failure is really frustrating.

[narual]

Why not convert it to screw drive?
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/208353-how-...-2-8-a-15.html

[Canada_Rockies]

I gave up on the third failure with mine and went the opposite end of the spectrum: DA-L 55-300. At least it works, but I do miss the IQ of the 50-135, the quick shift. Do it over again, I'd keep it and use it with the AFA 1.7X. It would give me an 85-230 f/4.76. I had tried it a couple of times with the 1.7 and it worked really well.

[maxfield_photo]

I dropped my 50-135 back in May of 2013, and sent it in to CRIS. It took them quite a while to repair it, I didn't get it back until mid October. According to their site the parts were on backorder from the manufacturer, but I hear a rumor through the grapevine that they were waiting on new, stronger SDM motors from Ricoh. I'm hoping that was the case, but then I never had any problems with the old SDM motor in the lens.

I DO however have a problem with the SDM contacts in my K20d. I was changing lenses, didn't notice I had the camera on, and I think I started to cross thread the bayonet, and inadvertently shorted out the SDM circuit in the camera. But here's the thing, my 50-135 now operates with the screwdrive. I'm thinking if the camera can't detect that an SDM lens is attached, it defaults to using the screwdrive. It might be worth trying to cover your contacts on the lens with a piece of electrical tape. You'll have to do it at your own risk because you don't want to gunk up anything, but you might find that you don't need to have your lens repaired after all.


[Edit: Oh, didn't know about the debug mode trick that Natural linked. That sounds safer, try that first]

[k5astro]

Uugh! SDM Fixed by C.R.I.S. three years ago, minus a month. SDM failed again. If the optical quality of this lens wasn't so great, I'd sell the stupid thing.

I'm not really happy with Pentax DA lenses. I have a DA 17-70 which is great except that it hunts for focus unless I put my finger on the focus ring - it can be really annoying when you're trying to get a shot. I also have a DA*60-250 and have had a couple of scary instances when the SDM system would not move as if the motor was weak. I figured it needed prodding so I exercised the focus ring manually until finally the thing would start working. So now every time I take it out, I exercise the focus ring manually, then using autofocus near-far-near-far etc. Then it works as expected.

Now I've just seen a video about a budget pro camera system and the guy recommended the K5iis (before K3 release) but no pentax lenses. He recommended all Tamron F2.8 lenses.

However, I have a couple of screw drive FA lenses and they are un-categoricly great lenses.

[narual]

The only problem I've had with my screw drive 50-135 is gravity. It landed square on the hood, smashed the filter, and broke something loose inside. sending it for repairs when I finally get dug out from the blizzard.

It will be a little louder of course, but hey, it will get a speed boost for free with every screwdriver motor upgrade pentax applies to a new body.

[psychdoc]

Sorry to hear about your problems.

I dropped my 50-135 about 3 months ago while removing it from the tripod and it looked pretty bad [like the barrel was fractured] and I debated about spending the money vs getting a tamron 70-200 instead but that is too big a lens.

In any case it was repaired by CRIS within a month or so for about 300 dollars. They said they replaced a bunch of little things and also the sdm motor. Seems to work perfectly. However, mine never had a problem with the sdm before I dropped it. I hope the new sdm motor stays as problem free as the old one as I must have had one of the good ones... So far so good though.

[stevebrot]

So...Is this a rant or a request for technical assistance?


Steve

[sterretje]

I DO however have a problem with the SDM contacts in my K20d. I was changing lenses, didn't notice I had the camera on, and I think I started to cross thread the bayonet, and inadvertently shorted out the SDM circuit in the camera.

You're number two, I guess: https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/85877-i-bro...t-happier.html