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How to deactivate SDM and allow for screw drive autofocus with DA* 16-50mm f/2.8

mercredi 2 janvier 2013, par Clover


ATTENTION PLEASE : THIS IS UNOFFICAL INSTRUCTIONS, FOLLOW THEM AT YOUR ONWN RISK.

This article is born after a long and interesting thread on pentaxkpark.com
[url=http://www.pentaxkpark.com/t37712-k20d-desactivation-du-mode-sdm][K20D] D[/url]
Thanks again, to poildegris for his help and also to nicokoscom55 for his work, I am only the messenger

Let’s start.

Few Pentax lenses have the ability to do autofocus with SDM or with the motor inside the body if the body does not allow SDM.

These SDM * lenses are :
- smc PENTAX-DA* 16-50mmF2.8 ED AL [IF] SDM
- smc PENTAX-DA* 50-135mm F2.8 ED [IF]SDM
- smc PENTAX DA* 60-250mm F4ED [IF] SDM
- smc PENTAX-DA* 200mmF2.8 ED[IF] SDM
- smc PENTAX-DA* 300mmF4 ED[IF] SDM

The process begins likely as updating the firmware, with press and holding MENU button, but we will not use a firmware but a Text document created as written in Pentax-hack.info website

[url=http://www.pentax-hack.info/documents/debug.html]Debug mode[/url]

Each command will need a different SD card or to rewrite the MODSET file.

Main steps are
- 1 Using a file to access the debug mode
- 2 Using a file to show the list of commands and then save the original EEPROM
- 3 Changing the EEPROM file with notepad++ or the Body it self
- 4 Load the modified EEPROM inside the lens
- 5 deseactivating the debug mode

The easiest is to use a Pentax K-7 with PKTETHER.

As I do not own a 50-135mm, I will only talk about the process using a 16-50mm DA* with my K-7.
I will write an article for 50-135mm soon ( and 60-250mm when I achieve to make it with )

Let’s start after the battery fully charged and the 16-50mm mounted on it.

STEP 1
Here is the process using a Pentax K-7

Download PKTETHER
http://www.pktether.com/

Plug your K-7 to your computer using the USB cable ( sold with the body) and launch PKTETHER
Switch ON the DEBUG MODE by click on CAMERA DEBUG MODE ON

STEP 2
TAke back your SD card and, using Notepad, create a file nammed MODSET.474
inside, only write (after un blank line) :

[OPEN_DEBUG_MENU]

Put the file in the root of the SD cardPut the card inside the switched Off DSLR.
Press and Hold MENU button and switch on the DSLR.

If everything OK, it will show you all options avaible on Debug mode :
Beware to not change a thing you do not need ( once again, all this are made at your own risk)

Use the pad to go to the line
LENS ROM CAMERA=>SD

Make a saved file of the EEPROM to allow you to reverse the process in cas of troubles

STEP 3
To modify the EEPROM, you can
- Either access the LENSEEP.LNS file you create by saving the file, I ask you to use Notepad++ [url=http://notepad-plus-plus.org/fr/]Notepad++ Home[/url]
- Or go to the line :
LENS EEPROM READ/WRITE
You can change the code line by line

Using NOTEPAD++ : DO NOT FORGET TO SAVE A FILE AND MODIFY A COPY FOR YOUR OWN SECURITY

Then change the code "C0" by "80" in the colonn 03,for the following lines

  • 0020
  • 0060
  • 00A0
  • 00E0
  • 0120
  • 0160
  • 01A0
  • 01E0
  • 0220
  • 0260
  • 02A0
  • 02E0
  • 0320
  • 0360
  • 03A0
  • 03E0

Using the DSLR directly : DO NOT FORGET TO SAVE A FILE AND MODIFY A COPY FOR YOUR OWN SECURITY
Access the line
LENS ROM EDIT R/W using the pad and the OK button.
Using the pad and dial, access the READ /WRITE function, check by read the info before modify it. Really check the info at the adress before change it. You need to read "C0" WRITE "80"

  • 0023
  • 0063
  • 00A3
  • 00E3
  • 0123
  • 0163
  • 01A3
  • 01E3
  • 0223
  • 0263
  • 02A3
  • 02E3
  • 0323
  • 0363
  • 03A3
  • 03E3

STEP 4
Put the modified fil LENSEEP.LNS in the root of the card and load it as using the Debug mod ( line under the line you use for saving the file )

LENS ROM DAT SD => CAMERA

STEP 5

Check your lens on the DSLR, the SDM will no more work.

Then Plug your K-7 to your computer and launch PKTETHER
Switch off the DEBUG MODE by click on CAMERA DEBUG MODE OFF

Tadaaaaaa

If everything OK, you did it, the DSLR will work as before, and the 16-50mm will not use SDM on any DSLR unlast you relaod the old LENSEEP.LNS.

4 Messages

  • DO YOU KNOW THE MODEST EXTENSON .XXX NUMBER FOR THE Kr ?

    Thanks in adavnce,
    Crocomikel

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  • This is just great !
    My 2.8 16-50 ED AL IF SDM works with autofocus again ! (25/03/2014)
    But now without the SDM, which worked only for about 500 shots....
    How awful that Pentax produces this kind of error ; and that after using Pentax for 30 years. I still have all the bodies and lenses, they still work fine and never had a problem... but thats a different matter... :-)
    Many thanks to all you competent people who figured this out and took the time to share it with us.

    However, I have a few remarks that might help others :

    - My K7 had firmware V1.12 and I couldn’t get it to work so I changed back to 1.01, but that made no difference.
    - Still in V1.01, I tought that maybe the "PKTETHER" didn’t work ; it opened and controled the K7 but it refused to go into DEBUG.
    - I looked at all the information pages again and studied this page in detail : [url=http://www.pentax-hack.info/documen...]Debug mode[/url] a got a minor brainwave :

    - Why not control the K7 with these commands on the SD directly instead of with PKTETHER ?
    - This worked great :
    - I made a modset.474 file as sugested on this page and with notepad++ made the commands :

    0
    1 [DEBUG_MODE EN]
    2 [OPEN_DEBUG_MENU]
    3 [SW_DEBUG_MENU EN]

    - Switched on the K7 while pressing menu and got into debug straight away.
    - Then followed the exact instructions as made on this page
    - When all was done I switched off the K7
    - Took out the sd card and changed the commands on the sd card with notepad++ to :

    0
    1 [DEBUG_MODE DIS]

    - Then switched of the K7
    - Took out the SD card and put in a clean SD card
    - Switched it on again and voila !!

    I haven’t switched back to firmware version v1.12, or even v1.13, being afraid to ruin everything again. The extra features of the v1.12/1.13 don’t realy interest me so I don’t want to take the risk.But I don’t think that the firmware version has anything to do with it.
    I sugest you try it with the latest version, see what happens and let us know !

    And now it’s back to using my autofocus again !

    Thanks again !
    KC

    PS : I’m dutch but live in France, so if you need help with this in frence, dutch or german feel free to drop me a line.

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