How To: Convert SDM to ScrewDrive + Video

Fila · 01-31-2023, 12:16 AM

Thank you very much, lens arrives today, and I am very tempted to try it. 50-135 mm would nicely complement 20-40, so I could find another home for my travel 18-135.
Just another question, can the conversion to screw drive be done with any of the following: K50, K3iii or KP?
If not, I will need somebody's help, which is another big - for the lens.

**UncleVanya** · 01-31-2023, 06:17 AM

Originally posted by Fila

Thank you very much, lens arrives today, and I am very tempted to try it. 50-135 mm would nicely complement 20-40, so I could find another home for my travel 18-135.

I own both of those combinations. I kept all three lenses. The 18-135 is more convenient when traveling - the 20-40 + 50-135 is more special.

Originally posted by Fila

Just another question, can the conversion to screw drive be done with any of the following: K50, K3iii or KP?
If not, I will need somebody's help, which is another big - for the lens.

No, the k-50 and KP bodies won’t be able to convert the lens. The debug mode can be entered on the k-50 and KP but the lens rom read and write functions don’t work. I’m unclear if the k3iii has a debug mode that is known, but no one has demonstrated that it can covert sdm lenses so far. The k3iii uses a different processor and operating system which may have very different underlying mechanisms.

deus ursus · 01-31-2023, 08:04 AM

I converted a lens with my K-5IIs ...

**Mikesul** · 01-31-2023, 08:51 AM

Can you give more details about how you used the K-5IIs? thanks

deus ursus · 01-31-2023, 09:02 AM

It's a while ago, so.I'm not quite sure, but I believe I followed the steps in the OP.

chrisd015 · 01-31-2023, 05:13 PM

Hi. I'm not 100% sure which lens+body combo you and Fila are referring to but I can confirm that I successfully converted my 50-135 to screw drive using my K-5 body following the instructions here.

**UncleVanya** · 01-31-2023, 06:07 PM - **1 Like**

Originally posted by deus ursus

I converted a lens with my K-5IIs ...

Originally posted by Mikesul

Can you give more details about how you used the K-5IIs? thanks

Originally posted by chrisd015

Hi. I'm not 100% sure which lens+body combo you and Fila are referring to but I can confirm that I successfully converted my 50-135 to screw drive using my K-5 body following the instructions here.

My reply earlier said "K-5" when I meant "K-50" it was a phone typo. I was replying to the person asking if their K-50, K3iii, KP could convert the lens. Yes the K-5 series appears to work. I don't use it myself so I don't know the details well. I know PKTETHER is one option but I think the SD Card trick to enter DEBUG works. Once in Debug the basics are the same. You take a copy of the file, edit it outside the camera (or on camera if you dare), save a copy and update the lens. Nothing complex. I can add color to this if needed.

deus ursus · 02-01-2023, 12:21 AM

Originally posted by UncleVanya

My reply earlier said "K-5" when I meant "K-50" it was a phone typo.

Ah! Those dreaded smartphone keyboards!

**UncleVanya** · 02-01-2023, 06:20 AM - **1 Like**

Originally posted by deus ursus

Ah! Those dreaded smartphone keyboards!

Lol. I shouldn’t complain. I’ve turned autocorrect off and found it was worse in many ways. I should proofread more.

rzvnz · 02-03-2023, 09:55 AM

Something odd is happening; I have converted a 16-50 with a K5IIs; I had 16 C0 values only on the 3rd row; changed them to 80. Now at 16mm, 50 mm and somewhere between my lens cannot focus at all because it is seen as a manual lens. Any ideas, please?

Asahiflex · 02-03-2023, 11:57 AM

Originally posted by rzvnz

Something odd is happening; I have converted a 16-50 with a K5IIs; I had 16 C0 values only on the 3rd row; changed them to 80. Now at 16mm, 50 mm and somewhere between my lens cannot focus at all because it is seen as a manual lens. Any ideas, please?

Did you make a backup of the original file? You could always do it again in case youe missed something (and even convert it back to SDM if you wish).

rzvnz · 02-03-2023, 12:17 PM

I have made a backup; I restored the original file and the lens is viewed correctly at all focal lengths, but the SDM is not working.

pimpim · 02-03-2023, 02:19 PM

Originally posted by rzvnz

I have made a backup; I restored the original file and the lens is viewed correctly at all focal lengths, but the SDM is not working.

Instead of editing the file you can use one of the 16-50 profiles available on dropbox. I tried this on my k5iis and it worked.

rzvnz · 02-03-2023, 07:53 PM

Originally posted by pimpim

Instead of editing the file you can use one of the 16-50 profiles available on dropbox. I tried this on my k5iis and it worked.

Can you point me to the dropbox link, please?

rzvnz · 02-03-2023, 09:11 PM - **1 Like**

Originally posted by rzvnz

Can you point me to the dropbox link, please?

I found the issue: at the left of the first column there are also a few C0 values that I accidentally modified; all is working normal now.

01-31-2023, 06:17 AM	#332
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,381	Originally posted by Fila Thank you very much, lens arrives today, and I am very tempted to try it. 50-135 mm would nicely complement 20-40, so I could find another home for my travel 18-135. I own both of those combinations. I kept all three lenses. The 18-135 is more convenient when traveling - the 20-40 + 50-135 is more special. Originally posted by Fila Just another question, can the conversion to screw drive be done with any of the following: K50, K3iii or KP? If not, I will need somebody's help, which is another big - for the lens. No, the k-50 and KP bodies won’t be able to convert the lens. The debug mode can be entered on the k-50 and KP but the lens rom read and write functions don’t work. I’m unclear if the k3iii has a debug mode that is known, but no one has demonstrated that it can covert sdm lenses so far. The k3iii uses a different processor and operating system which may have very different underlying mechanisms. Last edited by UncleVanya; 01-31-2023 at 06:05 PM.

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01-31-2023, 12:16 AM	#331
Fila Forum Member Join Date: May 2014 Posts: 93	Thank you very much, lens arrives today, and I am very tempted to try it. 50-135 mm would nicely complement 20-40, so I could find another home for my travel 18-135. Just another question, can the conversion to screw drive be done with any of the following: K50, K3iii or KP? If not, I will need somebody's help, which is another big - for the lens.

01-31-2023, 08:04 AM	#333
deus ursus Pentaxian Join Date: Nov 2012 Location: Stårheim, Norway Posts: 658	I converted a lens with my K-5IIs ...

01-31-2023, 08:51 AM	#334
Mikesul Loyal Site Supporter Join Date: Sep 2009 Location: Phoenix, AZ Posts: 7,591	Can you give more details about how you used the K-5IIs? thanks

01-31-2023, 09:02 AM	#335
deus ursus Pentaxian Join Date: Nov 2012 Location: Stårheim, Norway Posts: 658	It's a while ago, so.I'm not quite sure, but I believe I followed the steps in the OP.

01-31-2023, 05:13 PM	#336
chrisd015 New Member Join Date: May 2014 Posts: 2	Hi. I'm not 100% sure which lens+body combo you and Fila are referring to but I can confirm that I successfully converted my 50-135 to screw drive using my K-5 body following the instructions here.

01-31-2023, 06:07 PM - 1 Like	#337
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,381	Originally posted by deus ursus I converted a lens with my K-5IIs ... Originally posted by Mikesul Can you give more details about how you used the K-5IIs? thanks Originally posted by chrisd015 Hi. I'm not 100% sure which lens+body combo you and Fila are referring to but I can confirm that I successfully converted my 50-135 to screw drive using my K-5 body following the instructions here. My reply earlier said "K-5" when I meant "K-50" it was a phone typo. I was replying to the person asking if their K-50, K3iii, KP could convert the lens. Yes the K-5 series appears to work. I don't use it myself so I don't know the details well. I know PKTETHER is one option but I think the SD Card trick to enter DEBUG works. Once in Debug the basics are the same. You take a copy of the file, edit it outside the camera (or on camera if you dare), save a copy and update the lens. Nothing complex. I can add color to this if needed.

02-01-2023, 12:21 AM	#338
deus ursus Pentaxian Join Date: Nov 2012 Location: Stårheim, Norway Posts: 658	Originally posted by UncleVanya My reply earlier said "K-5" when I meant "K-50" it was a phone typo. Ah! Those dreaded smartphone keyboards!

02-01-2023, 06:20 AM - 1 Like	#339
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,381	Originally posted by deus ursus Ah! Those dreaded smartphone keyboards! Lol. I shouldn’t complain. I’ve turned autocorrect off and found it was worse in many ways. I should proofread more.

02-03-2023, 09:55 AM	#340
rzvnz New Member Join Date: Feb 2023 Posts: 4	Something odd is happening; I have converted a 16-50 with a K5IIs; I had 16 C0 values only on the 3rd row; changed them to 80. Now at 16mm, 50 mm and somewhere between my lens cannot focus at all because it is seen as a manual lens. Any ideas, please?

02-03-2023, 11:57 AM	#341
Asahiflex Pentaxian Join Date: Jan 2008 Location: Netherlands Photos: Gallery Posts: 2,795	Originally posted by rzvnz Something odd is happening; I have converted a 16-50 with a K5IIs; I had 16 C0 values only on the 3rd row; changed them to 80. Now at 16mm, 50 mm and somewhere between my lens cannot focus at all because it is seen as a manual lens. Any ideas, please? Did you make a backup of the original file? You could always do it again in case youe missed something (and even convert it back to SDM if you wish).

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02-03-2023, 12:17 PM	#342
rzvnz New Member Join Date: Feb 2023 Posts: 4	I have made a backup; I restored the original file and the lens is viewed correctly at all focal lengths, but the SDM is not working.

02-03-2023, 02:19 PM	#343
pimpim Senior Member Join Date: Sep 2010 Location: Mainz Photos: Albums Posts: 253	Originally posted by rzvnz I have made a backup; I restored the original file and the lens is viewed correctly at all focal lengths, but the SDM is not working. Instead of editing the file you can use one of the 16-50 profiles available on dropbox. I tried this on my k5iis and it worked.

02-03-2023, 07:53 PM	#344
rzvnz New Member Join Date: Feb 2023 Posts: 4	Originally posted by pimpim Instead of editing the file you can use one of the 16-50 profiles available on dropbox. I tried this on my k5iis and it worked. Can you point me to the dropbox link, please?

02-03-2023, 09:11 PM - 1 Like	#345
rzvnz New Member Join Date: Feb 2023 Posts: 4	Originally posted by rzvnz Can you point me to the dropbox link, please? I found the issue: at the left of the first column there are also a few C0 values that I accidentally modified; all is working normal now.