[Glen]

Has anyone been able to make this conversion to screw drive using a K3-II? I have a 50-135 and I wanted to convert it over but as I read the instructions and some other posts including this one at DP Review I am starting to think that I'm out of luck. I don't have access to an older Pentax to do the conversion.

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Last edited by Glen; 12-31-2017 at 10:00 PM.

[Duc-Driver]

Short answer : K3II (also K3) don't work for converting the lens.

[Berserker]

New to forum, Hello everyone. First I would like to thank everyone on this forum and outside of this forum for the excellent advice on converting SDM to screw drive. It works!!! I have fully updated k10, k20 and k1. I used the k10 to alter the file. The modset has to be named MODSET.TXT. Then fill in the appropriate commands. Do yourself a favour and download notepad++. Use the search, find, find and replace commands. It will make this task as easy as a walk in the park! I gave up on these lenses after 4 to 5 years of heartache. Even approached the Pentax booth at a show in Toronto, where I was greeted with laughing cries of how I won the bad lens in a million lottery! When they noticed I was not laughing they quickly took care of me. Had the 16-50 sent in via my local Henrys and the "motor was replaced". Worked for a month and a half before falling back to sleep! For the amount of money I paid for these 2 lenses, this problem should have been dealt with on a quick and professional level. I've been looking at the new lens lineup for the k1 but any PLM or SDM designation is enough for me to walk away! Good luck to all who needs to convert, don't give up, it is worth the time!

[UncleVanya]

Plm isn't the same nor is dc.

[Glen]

After much assistance from UncleVanya I have performed a lens conversion and reversed it. For anyone looking for a simple way to do the task, you should consider purchasing a K100d from Ebay or wherever you can find one at a reasonable price. In fact it doesn't even need to be fully functional as long as most of the electronics are fine and the subject lens will mount properly. I bought one on Ebay because my regular camera is a K3-II and that model (probably most models that came after the K-5) will not allow you to do the conversion. So, assuming that you have a K100d, the instructions are different from those described early in this thread and much simpler. Here we go. Oh wait, the disclaimer must come first. Continue at your own risk - I am not responsible for any damage that may occur to your equipment. I have no special training or experience and cannot attest to the results of this conversion beyond stating that it worked for me. Now we can proceed.

1. First check to ensure that you have put new batteries in your K100d. If the batteries die while doing this conversion you will be very disappointed with the outcome.
2. Place an SD card in the designated slot. It's best that it is a blank card. Do not close the SD card door.
3. Hold the INFO and AE-L buttons at the same time as you turn the camera body power on.
4. You have five seconds to do the following: Press MENU, press MENU again, press INFO. Three actions, one after the other. You are now in debug mode.
5. Press Menu again and then close the SD card door.
6. Select LENS EEPROM R/W and press OK.
7. Select LENS EEPROM STORE, the camera should say "wait".
8. Power down and remove the SD Card. Put it into a card reader for your PC and look to ensure there is a file called LENS SEEP.LNS. If not, try again.
9. Copy that file to a backup folder on your PC. That is your safety file in case something goes wrong. You can also use it to reverse the process from screw drive to SDM.
10. Use a text editor such as Notepad++ or even the one that is built into Windows. Any text editor (not a word processor) will do.
11. Now go to the start of this thread and follow the instructions for the 50-135 lens (I think they are pretty much the same for the 16-50 but you should confirm that with someone). I followed a slightly different process than shown on the video. Rather than changing all instances of C0 to 80 and then correcting the exceptions, I used the replace function in the text editor to go to the next instance of C0 (that is "C" and zero) and either replace, or if it is not in column 3, press next to skip that one and move to the next instance of C0. It just takes a minute either way but you will avoid errors this way. Only change those instances of C0 that are in column 3. I used Notepad++ and it even selected one of the row headings containing a "C0" so you want to watch for that; you only want to change column 3. When done save this to your SD card. There should only be one instance of the file on that card.
12. Follow the above instructions except when you get to EEPROM R/W, select LENS EEPROM LOAD.
13. Power down and power back up, reformat the SD card. Remove the lens and put it on your regular camera body to see if it is now working as a screw drive lens. If yes, you are done.

As you can see this is much simpler than the procedure with some later camera bodies. Remember that the above instructions are strictly for the K100d. For any other body make sure you do your research to find the correct method. You can't share the file you created with anyone else because it is lens specific. You can however convert someone else's 50-135 if you have their lens by following the above process.

Now go and do some photography!

[lotech]

I followed the steps to fix my 16-50 with my K3 but failed, I already download the pktether that support K3 and tethering worked, the problem was the lens data won't write to SD, but I tried to write all other data to SD without problem.

I then tried other way to edit the lens data on camera but that didn't work too, I can change the address to 0023 (column 3 ?) for example but the data return was 00, it should read C0 instead I believe, here is the link I followed :

How to deactivate SDM and allow for screw drive autofocus with DA* 16-50mm f/2.8 - Le site des amateurs de PENTAX

I got the 1.3 firmware wonder if this is the cause of the problem ?

Hello everyone!

After a lot of searching through the forms and help from dflorez, UncleVanya, and whoever made the dropbox link I was able to convert my lens. I had a hard time understanding the process, but I finally figured it out. I decided something this complicated needs a video. In this video I converted the 50-135mm lens, but I understand the process is the same for the 16-50, 60-250, 200, and 300mm lenses. I hope this is helpful to you and Good Luck!



The video is here: HOW TO: Convert SDM to ScrewDrive - Pentax - YouTube

Below you will see the process I followed. Again, I have the forums here to thank for giving me this information. I hope it helps you.




Too Much for you? Go here: SDM to Screwdrive Conversions - Page 3 - PentaxForums.com

Wanna give it a try? Keep Going.

NOTE: I am not responsible for any damage that my occur to your equipment. Continue at your own risk.

Stuff you need:
Dropbox- Pentax Hack Files: Dropbox - enable Debug Menu
Lens Hack Directions: How to deactivate SDM and allow for screw drive autofocus with DA* 50-135mm f/2.8 - Le site des amateurs de PENTAX
Pktether: Since the site is down due to malware, here is a link to the most recent version on my Google Drive: PK_Tether_0_7_0.zip - Google Drive
If the site ever gets fixed... you can go here. BUT DON'T right now (05/24/16) PK_Tether – Tethering Software for Pentax DSLR Cameras
Nopad++ (text editor): Notepad++ v6.9.2
Pentax Forums Other Links:
How to deactivate SDM and allow for screw drive autofocus with DA* 16-50mm f/2.8 - Page 41 - PentaxForums.com


My Steps
1.) Download PKTether (pktether site)
2.) Download Camera Hack files (drop box)
3.) Download Notepad++
4.) Open Pktether
5.) Place SD card into camera, connect camera to computer (USB cable)
6.) Turn on Camera In PKtether activate DEBUG MODE
7.) Copy Hack Files to SD card
8.) Disconnect camera from USB cable
9.) Power Down Camera, Power back on
You are in Development Menu
10.) Scroll down to "Lens Rom Camera=SD" and hit OK. (it should go black, and then you will see the same screen again)
11.) Power off camera, Move SD card to PC and open it
12.) You are looking for the LENSEEP.LNS file. MAKE A BACKUP of this file - THIS IS LENS COPY SPECIFIC - ONLY YOUR FILE WORKS WITH YOUR LENS!
13.) Open LENSEEP.LNS with Notepad++
14.) Replace ALL instances of "C0" in column "03" with "80". DO NOT REPLACE any instances of "C0" outside of column "03".
15.) Move the new LENSEEP.LNS file to your SD card (replacing the orginal, remember to back up the orginal)
16.) Power Camera on
17.) Scroll to "LENS ROM DAT SD= CAMERA" and hit OK ( you will see "Wait..." and then some text)
NOTE: It failed the first time for me, needed to do it twice
18.) When Complete, lens should be in screw Drive
19.) Disable Debug Mode
A.) Use camera settings Menue Button Scroll left until you see "Test Mode" Disable Debug Mode Hit OK
B.) Connect to PKtether, Click Debug Mode Off

[HarisF1]

I followed the steps to fix my 16-50 with my K3 but failed, I already download the pktether that support K3 and tethering worked, the problem was the lens data won't write to SD, but I tried to write all other data to SD without problem.

I then tried other way to edit the lens data on camera but that didn't work too, I can change the address to 0023 (column 3 ?) for example but the data return was 00, it should read C0 instead I believe, here is the link I followed :

How to deactivate SDM and allow for screw drive autofocus with DA* 16-50mm f/2.8 - Le site des amateurs de PENTAX

I got the 1.3 firmware wonder if this is the cause of the problem ?

It's not possible to do the conversion with the K-3 and newer bodies as the relevant code has been removed from the debug menu.

[lotech]

What codes removed ?
I can do all except reading lens data is that it ?

It's not possible to do the conversion with the K-3 and newer bodies as the relevant code has been removed from the debug menu.

[HarisF1]

What codes removed ?
I can do all except reading lens data is that it ?

When I tried it, it seemed as though the option to save the lens rom had no effect. Someone else mentioned there was no code behind the command so there doesn't seem to be any way to modify the lens rom using the K-3.

[clackers]

When I tried it, it seemed as though the option to save the lens rom had no effect. Someone else mentioned there was no code behind the command so there doesn't seem to be any way to modify the lens rom using the K-3.

I used my K-x, Haris - no problems with it.

[lotech]

That sounds like Pentax removed that part of codes on the K3 on purpose !

When I tried it, it seemed as though the option to save the lens rom had no effect. Someone else mentioned there was no code behind the command so there doesn't seem to be any way to modify the lens rom using the K-3.

[HarisF1]

I used my K-x, Haris - no problems with it.

The feature seems to have been removed from the K-3 series onwards. The K-5 still has the ability to alter lens roms AFAIK.

[lotech]

I read that couple years back,
I still try coz I found a new pktether for the K3

The feature seems to have been removed from the K-3 series onwards. The K-5 still has the ability to alter lens roms AFAIK.

[UncleVanya]

I read that couple years back,
I still try coz I found a new pktether for the K3

PK Tether isn't the issue, the issue is the camera lacks any ability to write the data back to the lens.

[lotech]

While trying to convert my 16-50 to screw drive an idea pop up in my mind, it is actually a re-think of an idea I brought up earlier. I wonder if situational auto switch between SDM and screw drive feasible ? for example, if the focus is far off the camera uses screw drive to bring the lens into near focus quick, and then pass to SDM for silent fine tuning, or use screw drive only in case the SDM failed, to make a professional grade lens more reliable, this is completely do-able just a s/w thing, but may be a silly waste of time too !

I don't know if Nikon/Canon lenses have both drive option built into their lenses and how they do the focusing, and I don't know why Pentax decided to disable the lens data R/W feature in debug mode to made it impossible to do the screw drive hack on the K3, they should instead provide a user feature to switch between SDM and screw drive ! I don't want to purchase an early model for this hack, I would rather save the fund for a fullframe. I can only hope the hackers can crack the secret, so that I can turn my near paper weight but optically perfect lens back to life !