DA* 50-135 overexposes and squeaks too.

mrjamesabels · 10-26-2011, 08:42 AM - **1 Like**

I bought a used 50-135 and after 2 months it started to squeak when focussing. No returns possible. Also, it over exposes as I stop down past f/2.8 to f/8 and worse in Av priority. So the metering info between the lens and body is having an issue. I tried cleaning the contacts with a lens cloth. I rubbed it really good but no difference. Do I need to use alcohol? Should I send in for repair? Is there a diy guide to fixing this? Also, I not happy with the AF performance. I swear it was decent when I first got it but it was so lousy in a low light wedding I recently did.

**manishved** · 10-26-2011, 08:47 AM

Squeaking = failing (or already failed) SDM. Its high time Pentax gave us the firmware update to enable the non-SDM AF mode.

JohnX · 10-26-2011, 09:51 AM

Take a look here > DIY SDM repair v1.0, but only if it stops completely.

Haven't/wouldn't do it myself, but...

I've seen a few threads where lenses have been resurrected by using them manually for a short while, but can't point you at them I'm afraid.

Lack of regular use seems to be an issue, so I give mine a work-out every few weeks. No problems yet.

**Fontan** · 10-26-2011, 08:31 PM

Oh yeah. Mine squeaks like rabbits being ran over by a truck.

mrjamesabels · 10-26-2011, 09:26 PM

But whats up with the over exposing? Aside from the huge problems, the images are very good in sharpness, contrast and color.(When properly focussed!)

mrjamesabels · 10-28-2011, 09:28 AM

Anyone know where to buy the sdm motor?

10-26-2011, 08:42 AM - 1 Like	#1
mrjamesabels Senior Member Join Date: Jan 2010 Location: NEW JERSEY USA Photos: Gallery \| Albums Posts: 198	*DA 50-135 overexposes and squeaks too.** I bought a used 50-135 and after 2 months it started to squeak when focussing. No returns possible. Also, it over exposes as I stop down past f/2.8 to f/8 and worse in Av priority. So the metering info between the lens and body is having an issue. I tried cleaning the contacts with a lens cloth. I rubbed it really good but no difference. Do I need to use alcohol? Should I send in for repair? Is there a diy guide to fixing this? Also, I not happy with the AF performance. I swear it was decent when I first got it but it was so lousy in a low light wedding I recently did.

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10-26-2011, 08:47 AM	#2
manishved Loyal Site Supporter Join Date: Mar 2008 Location: N. Calif Photos: Gallery \| Albums Posts: 3,652	Squeaking = failing (or already failed) SDM. Its high time Pentax gave us the firmware update to enable the non-SDM AF mode.

10-26-2011, 09:51 AM	#3
JohnX Pentaxian Join Date: Jul 2009 Location: London Posts: 1,116	Take a look here > DIY SDM repair v1.0, but only if it stops completely. Haven't/wouldn't do it myself, but... I've seen a few threads where lenses have been resurrected by using them manually for a short while, but can't point you at them I'm afraid. Lack of regular use seems to be an issue, so I give mine a work-out every few weeks. No problems yet.

10-26-2011, 08:31 PM	#4
Fontan Site Supporter Join Date: Jan 2011 Location: 5th floor Posts: 1,610	Oh yeah. Mine squeaks like rabbits being ran over by a truck.

10-26-2011, 09:26 PM	#5
mrjamesabels Senior Member Join Date: Jan 2010 Location: NEW JERSEY USA Photos: Gallery \| Albums Posts: 198 Original Poster	But whats up with the over exposing? Aside from the huge problems, the images are very good in sharpness, contrast and color.(When properly focussed!)

10-28-2011, 09:28 AM	#6
mrjamesabels Senior Member Join Date: Jan 2010 Location: NEW JERSEY USA Photos: Gallery \| Albums Posts: 198 Original Poster	Anyone know where to buy the sdm motor?