SMC DA 50mm F1.8 AF issue

ferin · 12-20-2014, 03:01 PM

Today i get new SMC Pentax-DA 50mm F1.8 for my K-50. Surprisingly AF doesn´t work. In all modes ( .AF.S .C .MF) shows only MF. In AF Settings AF.A is inactive and also Lens correction is inactive.I have latest firmware version 1.02 on my camera. Any ideas what happend? Thanks.

Na Horuk · 12-20-2014, 03:08 PM

When you mount this lens, can you use all the modes (Av, P, Tv) normally, or do they all say Av on the LCD screen? Does the camera ask you to input the focal length?
Here is I suggest:
- dismount the lens
- make sure the lens and camera mount are both clean of grime or particles
- mount the lens carefully, make sure you twist it all the way until it CLICKS into place. This can be a tight fit, especially with brand new lenses
- make sure the AF/MF button on the camera is set to AF. (and that AF works with other lenses)

If none of this solves the problem, you might have to return the lens. Maybe it got damaged during transport/shipping, or even a fault product was sent out. DA 50mm f1.8 is a good quality lens, and it should have fast AF

rawr · 12-20-2014, 03:16 PM

Have you mounted the lens properly?
Does manual focus work?
Did you turn the camera off before mounting the lens?
Do you have something on the lens (or are you holding it wrong?) that is stopping the focus ring from rotating?

Docrwm · 12-20-2014, 03:23 PM

Clean contacts.
Full charge on battery.
Correctly seat lens.
Turn camera on with AF selected.
?

If all else fails try resetting the camera in the menus to factory default.

Good Luck and welcome to PentaxForums.

ferin · 12-20-2014, 03:54 PM

Thanks for super fast reply

This issue is on all modes the same, manual focusing works well, AF not. The camera is realy asking to input focal length. Lens is new and fits ok. My other lenses (DA 18-55 and DA 50-200) works without any problems. Mechanicaly looks and works the lens ok. Contacts cleaned, factory reset done, unfortunately the problem stays. I think it will be really manufacturing defect. Lens is not comunicating with camera. I´m also able to set f/1.7 even it is f/1.8 lens.

Docrwm · 12-20-2014, 04:00 PM

Unfortunately it looks like you have a DOA lens. Sorry. BTW, the 50/1.8 has been thought to actually be a 1.7 that was artificially limited to 1.8 for marketing reasons.

RobG · 12-20-2014, 04:03 PM

Originally posted by ferin

Thanks for super fast reply

This issue is on all modes the same, manual focusing works well, AF not. The camera is realy asking to input focal length. Lens is new and fits ok. My other lenses (DA 18-55 and DA 50-200) works without any problems. Mechanicaly looks and works the lens ok. Contacts cleaned, factory reset done, unfortunately the problem stays. I think it will be really manufacturing defect. Lens is not comunicating with camera. I´m also able to set f/1.7 even it is f/1.8 lens.

From your description as you say, the lens isn't connecting eletronically to the camera, so the camera thinks it is a non-AF lens. You should make a warranty claim, and return it.

ferin · 12-20-2014, 04:29 PM

It's a shame but i think making a warranty claim will be the only option. Many thanks for your answers ;-)

Docrwm · 12-20-2014, 04:54 PM

Originally posted by ferin

It's a shame but i think making a warranty claim will be the only option. Many thanks for your answers ;-)

Can't return it? Sorry for your troubles.

ferin · 12-23-2014, 04:19 PM

Problem solved - it was really manufacturing defect. Warranty claim accepted. New lens on the way, hopefully will work better.

Docrwm · 12-23-2014, 05:17 PM

Originally posted by ferin

Problem solved - it was really manufacturing defect. Warranty claim accepted. New lens on the way, hopefully will work better.

Very happy that it was solved!

r0ckstarr · 12-23-2014, 09:30 PM

I had the exact same issue with a 10-17 fisheye.

https://www.pentaxforums.com/forums/131-visitors-center/281300-sigma-70-300mm...pentax-k3.html

Sent it back to B&H and a replacement is on the way.

12-20-2014, 03:01 PM	#1
ferin New Member Join Date: Dec 2014 Posts: 4	SMC DA 50mm F1.8 AF issue Today i get new SMC Pentax-DA 50mm F1.8 for my K-50. Surprisingly AF doesn´t work. In all modes ( .AF.S .C .MF) shows only MF. In AF Settings AF.A is inactive and also Lens correction is inactive.I have latest firmware version 1.02 on my camera. Any ideas what happend? Thanks.

12-20-2014, 03:16 PM	#3
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Have you mounted the lens properly? Does manual focus work? Did you turn the camera off before mounting the lens? Do you have something on the lens (or are you holding it wrong?) that is stopping the focus ring from rotating? Last edited by rawr; 12-20-2014 at 03:21 PM.

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12-20-2014, 03:08 PM	#2
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	When you mount this lens, can you use all the modes (Av, P, Tv) normally, or do they all say Av on the LCD screen? Does the camera ask you to input the focal length? Here is I suggest: - dismount the lens - make sure the lens and camera mount are both clean of grime or particles - mount the lens carefully, make sure you twist it all the way until it CLICKS into place. This can be a tight fit, especially with brand new lenses - make sure the AF/MF button on the camera is set to AF. (and that AF works with other lenses) If none of this solves the problem, you might have to return the lens. Maybe it got damaged during transport/shipping, or even a fault product was sent out. DA 50mm f1.8 is a good quality lens, and it should have fast AF

12-20-2014, 03:23 PM	#4
Docrwm Veteran Member Join Date: Sep 2010 Location: Somewhere in the Southern US Photos: Gallery \| Albums Posts: 12,285	Clean contacts. Full charge on battery. Correctly seat lens. Turn camera on with AF selected. ? If all else fails try resetting the camera in the menus to factory default. Good Luck and welcome to PentaxForums.

12-20-2014, 03:54 PM	#5
ferin New Member Join Date: Dec 2014 Posts: 4 Original Poster	Thanks for super fast reply This issue is on all modes the same, manual focusing works well, AF not. The camera is realy asking to input focal length. Lens is new and fits ok. My other lenses (DA 18-55 and DA 50-200) works without any problems. Mechanicaly looks and works the lens ok. Contacts cleaned, factory reset done, unfortunately the problem stays. I think it will be really manufacturing defect. Lens is not comunicating with camera. I´m also able to set f/1.7 even it is f/1.8 lens.

12-20-2014, 04:00 PM	#6
Docrwm Veteran Member Join Date: Sep 2010 Location: Somewhere in the Southern US Photos: Gallery \| Albums Posts: 12,285	Unfortunately it looks like you have a DOA lens. Sorry. BTW, the 50/1.8 has been thought to actually be a 1.7 that was artificially limited to 1.8 for marketing reasons.

12-20-2014, 04:03 PM	#7
RobG Otis Memorial Pentaxian Join Date: Dec 2009 Location: Canberra Photos: Gallery \| Albums Posts: 8,902	Originally posted by ferin Thanks for super fast reply This issue is on all modes the same, manual focusing works well, AF not. The camera is realy asking to input focal length. Lens is new and fits ok. My other lenses (DA 18-55 and DA 50-200) works without any problems. Mechanicaly looks and works the lens ok. Contacts cleaned, factory reset done, unfortunately the problem stays. I think it will be really manufacturing defect. Lens is not comunicating with camera. I´m also able to set f/1.7 even it is f/1.8 lens. From your description as you say, the lens isn't connecting eletronically to the camera, so the camera thinks it is a non-AF lens. You should make a warranty claim, and return it.

12-20-2014, 04:29 PM	#8
ferin New Member Join Date: Dec 2014 Posts: 4 Original Poster	It's a shame but i think making a warranty claim will be the only option. Many thanks for your answers ;-)

12-20-2014, 04:54 PM	#9
Docrwm Veteran Member Join Date: Sep 2010 Location: Somewhere in the Southern US Photos: Gallery \| Albums Posts: 12,285	Originally posted by ferin It's a shame but i think making a warranty claim will be the only option. Many thanks for your answers ;-) Can't return it? Sorry for your troubles.

12-23-2014, 04:19 PM	#10
ferin New Member Join Date: Dec 2014 Posts: 4 Original Poster	Problem solved - it was really manufacturing defect. Warranty claim accepted. New lens on the way, hopefully will work better.

12-23-2014, 05:17 PM	#11
Docrwm Veteran Member Join Date: Sep 2010 Location: Somewhere in the Southern US Photos: Gallery \| Albums Posts: 12,285	Originally posted by ferin Problem solved - it was really manufacturing defect. Warranty claim accepted. New lens on the way, hopefully will work better. Very happy that it was solved!

12-23-2014, 09:30 PM	#12
r0ckstarr Veteran Member Join Date: Sep 2009 Location: Texas Photos: Gallery Posts: 3,507	I had the exact same issue with a 10-17 fisheye. https://www.pentaxforums.com/forums/131-visitors-center/281300-sigma-70-300mm...pentax-k3.html Sent it back to B&H and a replacement is on the way.