K20D + Tamron 17-50mm autofocus halts

Bartolo · 02-14-2011, 03:05 AM

Hello Pentax People,
First of all I would like to say that I'm also happy pentax camera user since few years, I had been using film cameras, had switched to k10d and currently I am using fantastic camera k20D.

Few months ago I bought awesome lens Tamron 17-50mm f2.8 which was positively reviewed by professionalls. Pictures taken are really sharp and since I attached it to the body it became my favourite lens. But recently I noticed some strange behaviour. When I am focusing with this lens ie. in AF.C mode after few half presses it halts. In AF.S mode the same behaviour. I also notice that AF is not so fast as it was when I bought it. I was testing other lens but it does not stop, it works properly.

Have you ever experince this, or maybe this problem with the body?
Any feedback appreciated
Best regards,
Bartolo

bimjo · 02-14-2011, 06:49 AM

Hi Bartolo, welcome to the board.

Have you tried to clean the electrical contacts on the lens with a pencil eraser? It could be that they have become a little bit dirty over time and need to be cleaned. Since you are not having issues with other lenses I would give that a try.

hth

dougf8 · 02-14-2011, 07:04 AM

my 17-50mm became notchy when testing the focus manually. It would still work but I sent it off for repair anyway. Some £2.50 component had broken or worn out inside. It's back, repaired and works as I expect, pretty good IQ.

Also it has been calibrated for focus and is better than before.

EDIT: they replaced the Focus Drive Coupler

gp1806 · 02-14-2011, 07:13 AM

The little gold contacts on the lens are just gold plated. Gold plate is very soft, abrasive could wear the gold off eventually. Try a cotton bud (swab) damp with rubbing alcohol, damp not dripping, just a enough alcohol.

Bartolo · 02-14-2011, 08:32 AM

Thank you guys for all your advices

I will test them just when I come back home, I am still at work

Bartolo · 02-16-2011, 05:43 AM

Hello again,
I was cleaning with alcohol lens's contacts and body's as well the behaviour of my tamron is the same. It focuses 5-10 times and freezes, then I cannot see the red AF squere and there is no movement of the lens rings.
@dougf8 did your notchy lens have the same problems?
Thanks in advanced for any answer.

dougf8 · 02-16-2011, 02:56 PM

No, in all respects the lens was fine. Focus was as it should be. Just with the lens off the camera the focus ring was not 100% smooth. It would snag in a couple of places. I stopped using it pretty quick and sent it off for assessment. The repairer quoted and I agreed. If you don't want the repair you need to pay postage back. So at worst you're looking at 2* freight costs to see (expert repairer) if it is the lens that's wrong. Here in the UK it would have been about £16.

Keep on looking.....

**ChipB** · 02-16-2011, 03:45 PM

Not sure about the Tamron warranty in your country, but the Tamron USA warranty is 6 years. You might consider sending it in for warranty repairs.

dougf8 · 02-17-2011, 10:28 PM

Originally posted by ChipB

Not sure about the Tamron warranty in your country, but the Tamron USA warranty is 6 years. You might consider sending it in for warranty repairs.

5 years in the UK. But I bought 2nd hand and warranty not transferable even if I could remember who I got it from.

02-14-2011, 03:05 AM	#1
Bartolo New Member Join Date: Mar 2010 Location: Krakow Posts: 6	K20D + Tamron 17-50mm autofocus halts Hello Pentax People, First of all I would like to say that I'm also happy pentax camera user since few years, I had been using film cameras, had switched to k10d and currently I am using fantastic camera k20D. Few months ago I bought awesome lens Tamron 17-50mm f2.8 which was positively reviewed by professionalls. Pictures taken are really sharp and since I attached it to the body it became my favourite lens. But recently I noticed some strange behaviour. When I am focusing with this lens ie. in AF.C mode after few half presses it halts. In AF.S mode the same behaviour. I also notice that AF is not so fast as it was when I bought it. I was testing other lens but it does not stop, it works properly. Have you ever experince this, or maybe this problem with the body? Any feedback appreciated Best regards, Bartolo

02-14-2011, 07:04 AM	#3
dougf8 New Member Join Date: Aug 2009 Location: Cornwall Posts: 13	my 17-50mm became notchy when testing the focus manually. It would still work but I sent it off for repair anyway. Some £2.50 component had broken or worn out inside. It's back, repaired and works as I expect, pretty good IQ. Also it has been calibrated for focus and is better than before. EDIT: they replaced the Focus Drive Coupler Last edited by dougf8; 02-14-2011 at 01:44 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale - Sold: [US] K20D, Metz 58 AF-1 Flash, FA 50mm 1.4, Tamron 17-50mm 2.8, Tamron 18-250m	jasonfen	Sold Items	11	06-20-2010 06:32 AM
For Sale - Sold: Pentax K20D, FA 35mm 2.0, FA 50mm 1.4, Sigma 12-24mm, Tamron 90mm, D-BG2, TTL	imadethis	Sold Items	15	02-09-2010 02:02 PM
Refurbed K20D won't autofocus	jacquestrapp	Pentax DSLR Discussion	10	11-03-2009 02:24 PM
K20D autofocus loud?	chse	Pentax DSLR Discussion	6	11-10-2008 04:28 AM
K20D AutoFocus.	blwnhr	Pentax DSLR Discussion	4	02-21-2008 11:34 PM

02-14-2011, 06:49 AM	#2
bimjo Veteran Member Join Date: Jan 2008 Location: Pasco, WA Posts: 967	Hi Bartolo, welcome to the board. Have you tried to clean the electrical contacts on the lens with a pencil eraser? It could be that they have become a little bit dirty over time and need to be cleaned. Since you are not having issues with other lenses I would give that a try. hth

02-14-2011, 07:13 AM	#4
gp1806 Veteran Member Join Date: Mar 2009 Location: Chicago suburbs Photos: Albums Posts: 848	The little gold contacts on the lens are just gold plated. Gold plate is very soft, abrasive could wear the gold off eventually. Try a cotton bud (swab) damp with rubbing alcohol, damp not dripping, just a enough alcohol.

02-14-2011, 08:32 AM	#5
Bartolo New Member Join Date: Mar 2010 Location: Krakow Posts: 6 Original Poster	Thank you guys for all your advices I will test them just when I come back home, I am still at work

02-16-2011, 05:43 AM	#6
Bartolo New Member Join Date: Mar 2010 Location: Krakow Posts: 6 Original Poster	Hello again, I was cleaning with alcohol lens's contacts and body's as well the behaviour of my tamron is the same. It focuses 5-10 times and freezes, then I cannot see the red AF squere and there is no movement of the lens rings. @dougf8 did your notchy lens have the same problems? Thanks in advanced for any answer.

02-16-2011, 02:56 PM	#7
dougf8 New Member Join Date: Aug 2009 Location: Cornwall Posts: 13	No, in all respects the lens was fine. Focus was as it should be. Just with the lens off the camera the focus ring was not 100% smooth. It would snag in a couple of places. I stopped using it pretty quick and sent it off for assessment. The repairer quoted and I agreed. If you don't want the repair you need to pay postage back. So at worst you're looking at 2* freight costs to see (expert repairer) if it is the lens that's wrong. Here in the UK it would have been about £16. Keep on looking.....

02-16-2011, 03:45 PM	#8
ChipB Site Supporter Join Date: Nov 2007 Location: Eau Claire, WI Photos: Gallery \| Albums Posts: 2,701	Not sure about the Tamron warranty in your country, but the Tamron USA warranty is 6 years. You might consider sending it in for warranty repairs.

02-17-2011, 10:28 PM	#9
dougf8 New Member Join Date: Aug 2009 Location: Cornwall Posts: 13	Originally posted by ChipB Not sure about the Tamron warranty in your country, but the Tamron USA warranty is 6 years. You might consider sending it in for warranty repairs. 5 years in the UK. But I bought 2nd hand and warranty not transferable even if I could remember who I got it from.

Thread Tools	Search this Thread
	Search this Thread: Advanced Search