K-5 Focus Questions

Once you get into these hidden menus and start making alterations, you are on your own. I suspect that warranty would be out the window as well.

It would be interesting to know how many cameras are returned that have been hacked, for want of a better word. I'm not surprised if Pentax have made it harder to get in to these areas.

When I run PK_Tether for the first time, I get a message 'Configuration file not found. Default configuration will be used.' When the program opens, everything is greyed out. Anyone have any ideas what settings need to be saved in the configuration file to get it to work with the K-5? BTW I'm running the latest PK_Tether, version 7.

Regards
David

Sorted it now - the camera needed a memory card installed for PK_Tether to recognise it!

Thanks to everyone for the helpful suggestions, particularly Algi.

Regards
David

Hi, I have installed and applied the value of +100 and it works cheers http://www.pktether.com/

All sorted now, thanks to Algi!! An adjustment of +100 in the Debug Mode, via PK_Tether and all is well! Most of my lenses now need little or no fine AF Adjustment and all are easily adjusted within the -10 to +10 AF Fine Adjustment option in the Menu. I suspect that my K-5 has been 'off' since I bought it, but it's performing brilliantly now that all the lenses are adjusted correctly.

The testing has also been interesting from a lens performance point of view. Here's some information on the lenses I adjusted, just for fun:

- Sigma 105mm F2.8 DG EX Macro - this is my sharpest AF lens by some distance - images are razor-sharp when blown up to 300% and there is virtually nil CA

- Sigma 150-500 (at 400mm) - This is the second sharpest of those I calibrated - great performance at 400mm, again very little CA

- Pentax DA L 55-300 (at 230mm) - Very good, just a whisker behind the Siggy, but still very sharp

- Pentax DA 17-70 (at 60mm) - Again very good, still pretty sharp, but not quite as good as the other three lenses calibrated

I was pixel-peeping at 300% for the above tests, so in real world use all of the above lenses will deliver excellent performance. What the tests have shown me is that it is vital to calibrate to get the very best from them - the differences with and without calibration can be quite significant.

Regards
David

Was the Sigma 150-500 out by much David? My DA*300 is +7 on the K30. Is there a thread on the best way to go about it. I used the line of AA batteries at 45 deg but wasn't certain if I should use the widest aperture during the test.
Dave

Hi Dave, the 150-500 was out by as much as the rest; +10 on the old K-5. After the adjustment in debug mode (+100) it now focusses accurately without any fine adjustment in the normal K-5 menu.

I used F8; this seems fine to carry out the tests. No need for any thread to give any detailed instructions, just follow these:

- Download and install PK_Tether version 7
- Connect the camera via the PC to USB lead to your computer
- Make sure there's an SD card in the camera and switch it on
- Run PK_Tether and set 'debug mode on'
- Use the menu on the camera to navigate through the menu options until you come to the Debug one
- In the Debug menu, select the AF Test option
- Set AF to + or - whichever you need; if most lenses are at + 7 in the fine adjustment (normal menu), +70 will be required
- Once this is completed, disable the debug mode via the camera's Debug menu and use the normal fine AF Adjustment to complete the job

Hope this makes sense.

Regards
David

Thanks David. I have PK Tether already but what about the actual test, what did you focus on to do the check accurately? Last time I used a line of AA batteries at 45 deg to the camera and focused on the middle one.

Hi Dave

I used a test chart, free in Amateur Photographer, placed square on to the camera, mounted the camera on a tripod and took three shots with differing AF Fine Adjustment settings. I then loaded these into Photoshop unaltered and compared them all at the same time in the horizontal tiled view at 300% magnification. Using this method it's easy to see which is sharpest. I continued this process by trial and error until I arrived at the sharpest setting.

The same process was followed with all my lenses. It seems to have worked - the results from the camera in real world shots are great now.

Regards
David

can you say what distance from lens to chart please David

I used a test chart which I set up at an angle to see if it was front or back focusing then tried different settings so I suppose it was similar. I think I will fine tune it now using your method.
Joe, I wouldn't think it matters too much but I'm guessing just outside the minimum focusing distance for the lens with a fairly wide aperture will maximise any errors.
Dave

Out of interest are there any k-5 owners who have spot on focus with all their lenses.

Since owning the mkii all my lenses are spot on razor sharp with no adjustments needing to be made, which means all my lenses are fine. Yet both my previous k-5 needed so much tweaking plus and minus I am beginning to wonder if its the poor af on the previous pentax bodies that was more an issue than any adjustments required.

My K5 is fine and much better with my 55 - 300 DA since the last update 1.14. (less hunting in high contrast skies) My 15mm Ltd has such a huge depth of field it's not going to be an issue. My 18- 135 DA WR has never been an issue.

My attitude to cameras and lenses thus far is if they were out I'd expect the warranty to cover the problem.

At telephoto for wildlife I've learned to use centre weighted metering, spot focus AFS and as high shutter speeds as possible.I also accept that it requires a great deal of patience. I really envy people like Alan in Blyth their getting up in the middle of the night with their Bigma's and all their patience.

Otherwise I guess the lack of critical fast star lenses in my bag means I do not have such critical shallow depths of field to suffer much of what I read on these forums.F8 has always been my starting aperture.

It differed with each lens as each has different minimum focus distances and different magnification. With the 150-500 it was at a distance of approximately 10 feet.

Regards
David

Bill, regarding your post above, even with a 55-300 lens at F8, focus accuracy is absolutely critical. Even slightly off causes the images to be out of focus; when taking pictures of wild birds, the focus needs to be spot-on the bird's eye and even a bit off renders the image useless in my eyes.

Fair enough, if you're using a 16-45 or something similar it's not too much of an issue, but with anything telephoto it is.

Regards
David