[willimone]

Hi all,
in March I purchased a second hand DA*16-50mm. When I received the packaged there was written that the lens was repaired in the past (I guess for the SDM fail) and then hardly used. Now I have been using it for a few months and the AF still works fine. However just in case for the future I wanted to see if it could be possible to convert the AF from SDM to screw drive. I have read and there are videos on youtube on how to do it but it seems that it is possible only for the older Pentax or the K1.

Are you aware if someone managed to do it with the K70?

Thanks

Pierangelo

[jatrax]

There is a user here @unclevanya that has in the past done the conversion. I do not think it can be done on a K-70 but UncleVanya can tell you for sure if that is possible and if not you can discuss converting.

[Not a Number]

You need to enable the debug mode on the camera. I think the last bodies that people were able to figure out how to do this were the K-5 series.

[stevebrot]

There is a user here @unclevanya that has in the past done the conversion. I do not think it can be done on a K-70 but UncleVanya can tell you for sure if that is possible and if not you can discuss converting.

I believe @UncleVanya also offers this as a service for a reasonable cost.


Steve

[willimone]

In the meanwhile thank you for your replies

[Kozlok]

Post some photos! This is an enthusiasts' forum. We love to see people's photos.

The 16-50 is lovely, and the SDM failures are real, but over-blown somewhat. Use it in good health, and getting it changed to screwdrive is easy enough. Just PM UncleVanya when the time comes, if it ever does.

[UncleVanya]

You need to enable the debug mode on the camera. I think the last bodies that people were able to figure out how to do this were the K-5 series.

Oddly it isn't that simple Even if you get into debug mode on some cameras (such as these as the k50 or k-3) have non-working options in the menu items needed to access and replace the lens file.

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Last edited by UncleVanya; 06-04-2020 at 12:33 PM.

[UncleVanya]

I have read and there are videos on youtube on how to do it but it seems that it is possible only for the older Pentax or the K1.

Are you aware if someone managed to do it with the K70?

The k1 can't convert these lenses, but it can use them. All Pentax DSLRs can use a lens converted to screw drive just fine. The conversion only changes the lens not the camera.

After the k-5 it stopped being possible to convert on more modern bodies. I can't affirm all modern models fail to contain working options, but my old k50 and k-3 failed.

[cpk]

Exercise the lens regularly. My 16-50 has always been okay for SDM focusing, but not my 50-135. Neither lens was used that often for a number of years, and the 50-135 would require me playing with it for 15-30 minutes just to get the SDM to work. Last year I spent about a month taking it out of storage almost every day and, once the focusing started to work, exercised ti by focusing on different distances in my apartment and through the windows for 30 minutes or so. Eventually it would focus immediately during these daily sessions. Now I do this exercising every two or three weeks.

[willimone]

Thank you folks for the tips - I will then try to exercise the lens regularly hoping that the SDM won't fail.
If it happened, I will then be probably here again asking what is the best thing to do.

Thank you all

[cpk]

I should add that my current exercising of the lens is for only 5 minutes or so to ensure the focusing is still working right away. The key is to keep using the lens even if only to exercise it.

[SunValley]

Exercise the lens regularly.

I find this only works with bodies using the D-Li90 battery (K-3s, K-5s and K-7). On my K-50 a fully charged battery has never been able to revive them, though I never tried for more than 10 min. My 16-50 and 50-135 started showing signs of sdm failures four years ago. I've been "exercising" them regularly since then.