DA* 16-50 with screwdrive AF, but manual focus doesn’t work

Bui · 05-29-2019, 11:21 PM

I am interested in an offer of a Pentax 16-50, with broken SDM, however, the owner also mentioned its focusing ring doesn’t work (hence no manual focus and no quick-shift), but the lens has been converted to screwdrive AF and it works fine. Is this possible? If that’s the case, is it worth it? He asks for 120 bucks and from the photos, physical condition looks ok. Thank you for advice :-)

cport · 05-30-2019, 01:46 AM

My experience with converted 16-50 is that it allows QS and manual focusing.

Jome · 05-30-2019, 03:25 AM

Hello, even with SDM down, it should work manually, can it also zoom freely?

steve_k · 05-30-2019, 04:21 AM - **2 Likes**

“Danger Will Robinson”. I wouldn’t touch it with a 10 ft pole unless it is free.

Sluggo · 05-30-2019, 04:37 AM

Disagreeing with the previous comment: if the screw drive autofocus works reliably and there aren't optical flaws, $120 seems a fair price for a 16-50. It might be the only lens in my bag that I have never once needed to use manual focus with.

**rogerstg** · 05-30-2019, 05:12 AM

Originally posted by Sluggo

if the screw drive autofocus works reliably and there aren't optical flaws, $120 seems a fair price for a 16-50. It might be the only lens in my bag that I have never once needed to use manual focus with.

Same here. It seems to be a good price for such a good lens.

**UncleVanya** · 05-30-2019, 05:32 AM

I've never seen one that worked that way. The ones that manual focus had failed on have also been unable to autofocus. But that isn't intended to mean that situation is not possible, just uncommon.

Without manual focus, you give up quickshift. You have more need to get focus fine tuning just right. But these aren't deal breakers.

Do you trust the seller? Is there any transaction guarantee?

Bui · 05-30-2019, 11:07 PM

No I don’t know the seller, plus he live in another city so no possibility to test the lens either. But I can pay him via Paypal so I guess it’s ok in term of safety department. Basically he said he bought the lens used in “dead” state, no SDM, no manual focus, then he converted it to screwdrive and it has been working fine. The zoom ring too. I’m interested in trying it ‘cause I also have a converted 50-135, they can make a good converted pair :-) but problem is I also have a Tamron 17-50, that is decent, but I don’t know why I don’t like it, perhaps I find its rendering bit lacking (I’m a fan of DA limiteds). Do you think the 16-50 can offer something different?

**UncleVanya** · 05-31-2019, 05:55 AM

Originally posted by Bui

No I don’t know the seller, plus he live in another city so no possibility to test the lens either. But I can pay him via Paypal so I guess it’s ok in term of safety department. Basically he said he bought the lens used in “dead” state, no SDM, no manual focus, then he converted it to screwdrive and it has been working fine. The zoom ring too. I’m interested in trying it ‘cause I also have a converted 50-135, they can make a good converted pair :-) but problem is I also have a Tamron 17-50, that is decent, but I don’t know why I don’t like it, perhaps I find its rendering bit lacking (I’m a fan of DA limiteds). Do you think the 16-50 can offer something different?

I've never used the K mount version of the 17-50, the only version I've used is Nikon. It seems comparable optically, but the 16-50 feels nicer.

**mikesbike** · 05-31-2019, 11:09 AM

There is definitely something fundamentally wrong if you cannot manually focus that lens. With a lens having A,F I do not often employ MF, but I want it there if I need it. Not having MF availability would also mean I must always depend on AF accuracy. How accurate is AF on this lens, which has a disabled MF function?

05-29-2019, 11:21 PM	#1
Bui Veteran Member Join Date: Nov 2016 Photos: Gallery Posts: 316	*DA 16-50 with screwdrive AF, but manual focus doesn’t work** I am interested in an offer of a Pentax 16-50, with broken SDM, however, the owner also mentioned its focusing ring doesn’t work (hence no manual focus and no quick-shift), but the lens has been converted to screwdrive AF and it works fine. Is this possible? If that’s the case, is it worth it? He asks for 120 bucks and from the photos, physical condition looks ok. Thank you for advice :-)

05-30-2019, 01:46 AM	#2
cport Pentaxian Join Date: Jan 2013 Posts: 428	... My experience with converted 16-50 is that it allows QS and manual focusing.

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05-30-2019, 03:25 AM	#3
Jome Pentaxian Join Date: Aug 2016 Photos: Albums Posts: 784	Hello, even with SDM down, it should work manually, can it also zoom freely?

05-30-2019, 04:21 AM - 2 Likes	#4
steve_k Site Supporter Join Date: Dec 2016 Location: Shelton, CT Photos: Albums Posts: 708	“Danger Will Robinson”. I wouldn’t touch it with a 10 ft pole unless it is free.

05-30-2019, 04:37 AM	#5
Sluggo Veteran Member Join Date: Sep 2006 Location: Ames, Iowa Photos: Gallery \| Albums Posts: 774	Disagreeing with the previous comment: if the screw drive autofocus works reliably and there aren't optical flaws, $120 seems a fair price for a 16-50. It might be the only lens in my bag that I have never once needed to use manual focus with.

05-30-2019, 05:12 AM	#6
rogerstg Loyal Site Supporter Join Date: Oct 2007 Location: Rhode Island Photos: Albums Posts: 1,168	Originally posted by Sluggo if the screw drive autofocus works reliably and there aren't optical flaws, $120 seems a fair price for a 16-50. It might be the only lens in my bag that I have never once needed to use manual focus with. Same here. It seems to be a good price for such a good lens.

05-30-2019, 05:32 AM	#7
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,409	I've never seen one that worked that way. The ones that manual focus had failed on have also been unable to autofocus. But that isn't intended to mean that situation is not possible, just uncommon. Without manual focus, you give up quickshift. You have more need to get focus fine tuning just right. But these aren't deal breakers. Do you trust the seller? Is there any transaction guarantee?

05-30-2019, 11:07 PM	#8
Bui Veteran Member Join Date: Nov 2016 Photos: Gallery Posts: 316 Original Poster	No I don’t know the seller, plus he live in another city so no possibility to test the lens either. But I can pay him via Paypal so I guess it’s ok in term of safety department. Basically he said he bought the lens used in “dead” state, no SDM, no manual focus, then he converted it to screwdrive and it has been working fine. The zoom ring too. I’m interested in trying it ‘cause I also have a converted 50-135, they can make a good converted pair :-) but problem is I also have a Tamron 17-50, that is decent, but I don’t know why I don’t like it, perhaps I find its rendering bit lacking (I’m a fan of DA limiteds). Do you think the 16-50 can offer something different?

05-31-2019, 05:55 AM	#9
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,409	Originally posted by Bui No I don’t know the seller, plus he live in another city so no possibility to test the lens either. But I can pay him via Paypal so I guess it’s ok in term of safety department. Basically he said he bought the lens used in “dead” state, no SDM, no manual focus, then he converted it to screwdrive and it has been working fine. The zoom ring too. I’m interested in trying it ‘cause I also have a converted 50-135, they can make a good converted pair :-) but problem is I also have a Tamron 17-50, that is decent, but I don’t know why I don’t like it, perhaps I find its rendering bit lacking (I’m a fan of DA limiteds). Do you think the 16-50 can offer something different? I've never used the K mount version of the 17-50, the only version I've used is Nikon. It seems comparable optically, but the 16-50 feels nicer.

05-31-2019, 11:09 AM	#10
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,552	There is definitely something fundamentally wrong if you cannot manually focus that lens. With a lens having A,F I do not often employ MF, but I want it there if I need it. Not having MF availability would also mean I must always depend on AF accuracy. How accurate is AF on this lens, which has a disabled MF function?