Archive for the ‘Uncategorized’ category

Debug mode on the Pentax K20D DSLR

January 5th, 2010

I really like my Pentax K20D DSLR, but when I first got it the autofocus was not accurate, particularly with my favourite FA 50mm 1.4 lens.   Fortunately the camera has an autofocus adjustment in the standard menu, which fixed the problem, but I recently discovered that there is a hidden ‘debug’ menu that offers even more control over autofocus.   However the procedure to turn on the debug menu is a little fiddly, so I thought I’d document it here.

[Note that these instructions only apply to the K20D.   Other Pentax and Samsung cameras also have a debug mode, but the instructions are slightly different for each camera – see the end of the post for links.]

Step 1: Create a text file called MODSET.442 in the root of your SD card.   The file should contain the following single line:


You can use any plain text editor, for example Windows Notepad.  Make sure that the file is called MODSET.442 and not MODSET.442.txt

Step 2: Put the SD card into the camera but leave the card door open.

Step 3: Hold down the Menu button and turn on the camera.  Keep holding down the Menu button until the debug menu appears.


Step 4:  Close the SD card door.

Step 5: To enable debug mode, press the right arrow to change Debug Mode from DIS to EN, then press the OK button.


Step 6: Press the MENU button to get to the standard camera menu.   (If nothing happens, make sure you have closed the SD card door.   If necessary, turn the camera off and on again after closing the door.)

Press the right arrow twice to get to the Setup menu:


This is just the standard Setup menu, but some new items have been added to the bottom.  Press the up arrow to quickly jump to the bottom to see them.


Select AF TEST then click the right arrow button.


You can now set the global focus correction.  In this screenshot the correction is set to –90 and I am about to increase it by 20 (making it –70).   Press the OK button and you are ready to take a test shot with your new AF setting.  (Some reports suggest that the camera must be restarted after setting the correction value, but it seems to apply immediately on my camera.)

Step 7:  Once you have finished playing with the AF correction, you will want to turn off the debug menu.  To do so, just turn the camera on and when the debug menu appears, set DEBUG MODE to DIS and click OK.   Your camera should now be totally back to normal.

You can leave the MODSET.442 on your SD card and then re-enable the debug menu at any time by starting from step 2.  Or you can just delete the file if you prefer.

If some part of the instructions doesn’t seem to be working, check your SD card door.   For some steps it must be open, and others it must be closed – follow the instructions exactly as above.

The debug menu is also available on several other Pentax and Samsung cameras – see the pentax-hack site for details.

Also there are detailed instructions for the Pentax K-x here, which I found very useful, even though the steps are slightly different than the K20D.

After many many test shots I think I’ve settled on –90 as my correction value.   That allows me to run my FA 50mm 1.4 with no ‘standard’ correction, and my other lenses seem happy too.

Given up on Vista

March 10th, 2007

So after a couple of months using Vista on my new laptop, I’ve given up and gone back to XP. The last straw was when Vista wouldn’t recognise my new digital camera, even though it’s just a standard USB disk device. After an hour or so of futile poking around in device manager, I finally did a google search and someone recommended telling Vista to look in c:\windows\system32 for the drivers it needs. Incredibly that worked, but by that time I was so furious I made up my mind to reinstall XP the next night.

It’s *so* good to be back on XP. Everything is faster, my disk isn’t constantly churning, my sound works properly (no stuttering), I can login using my fingerprint reader again, and Windows Explorer works properly. The only things I miss are the sidebar (solved by installing desktop sidebar), and the search in the start menu (which I can easily live without).

Don’t get me wrong, Vista is not terrible. It’s just that for me on this particular laptop, the pain outweighs the gain. Maybe I’ll try it again in a year or two, when we’ve had a couple of service packs and the drivers are all sorted out.

First impressions of Zune

January 9th, 2007

Got a free Microsoft Zune as part of a promotion related to my website, so I thought I’d post some thoughts.

Overall I have to say it’s a big disappointment. First of all, you can’t use it as an external drive, so you can’t store abitrary data on it. There is a hacky workaround circulating on the net, but it’s very kludgy. This limitation alone means I’d never recommend anyone buy one.

The second problem is the PC software (to sync your media with the Zune). The interface is truly awful. I found myself having to consult the help to work out how to do the most basic things. And the help isn’t much good either. Explaining this interface to a non-technical relative doesn’t bear thinking about. So think twice before buying one as a gift for someone.

I haven’t bothered signing up for the online marketplace stuff, so I can’t comment on that. But I read bad things about it, so I’m not really tempted to try.

As far the hardware goes, the screen is excellent – big and bright and very usable for looking at photos or even video. The controls are reasonably intuitive. The earphones are mediocre – not close to the quality of my 30 quid Sennheiser PX100 headphones. With decent headphones, the sound quality from the Zune seems fine – similar to my PC.

The software on the Zune itself is ok, but not great – the built-in themes are ugly (subjective, obviously), skipping between songs is slow, and the equalizer only has presets (no direct control over bass and treble). Oddly there seems to be hardly any noticable difference between the preset values – Rock has slightly more bass than Folk, for example, but it’s only noticeable at very high volumes.

Add in the fact that there’s no AC charger (I’m expected to take my laptop with me when travelling, obviously) and the whole Zune experience leaves a lot to be desired. I really can’t see myself using it. Probably end up on ebay. Along with quite a few others, I imagine.

BTW I have no experience with any other similar devices (e.g. IPod), so maybe they all suffer from similar problems. I doubt it, though.