[kypfer]

Dear friends, just in case it is not commonly known, it is possible to finetune the af on older Pentax models as well, though there is no such item in the standard menu.

To do so, you have to enter the debug mode. Fortunately the debug mode is built in in the *ist models and the K100D. The procedure I'll describe will not work for the K100D super though, for it needs to be fed with a so called modset file via the sd card.
I got this information from an old thread, wich can be found by searching for "Debug focus adjustment". Credits to the original poster "hayden"

hayden tested and confirmed it to be working on the original * ist D and the K100D both with 1.00 firmware. I can confirm it to be working with 1.02 firmware on the K100D too.

Step 1) Switch camera on while pressing AE-L and INFO buttons simultaniously. The back display now shows the installed firmware version for around five seconds.
Step 2) While the firmware version is being displayed press the MENU button twice, then the INFO button.
Step 3) Switch DEBUG MODE from DIS to EN, confirm witk OK. The Display now shows "WAIT HS..."
Step 4) Enter the menu and switch to "Set-up". The very last entry now says "AF TEST". There you can adjust the autofocus in um-steps. If the new entries do not show up immediately restart the camera.

For example, to cure a frontfocus on my K100D I had to dial in +250um. I noticed it only with my f/1.4 lens wide open, all my other lenses' dof is much larger when shot open, so they where in focus always without adjustment. My f/1.4 lens indeed is manually focused, but the benefit is when the focus confirmation shines up, the lens now truly is in focus, whereas before the adjustment when the confirmation shone, the focus was way off.

You can use the camera as usual while you're in debug mode, means you can adjust, then directly take a picture to check for af accuracy on your monitor

Step 5) After you're done, simply repeat Steps 1 to 3, only change DEBUG MODE from EN to DIS, confirm. You're back in normal operational mode.

For me it worked fine, though if you feel the need to give it a try, be aware you will do it on your own risk.

Good succes!

Just for reference, I've just checked this functionality with both my *ist DS (v.2.02) and my *ist DL2 (v.1.02) and the debug menu can be accessed on both cameras. I didn't feel the need to change anything so left well alone, but it may be of use in the future

[hjortron]

Dear friends, just in case it is not commonly known, it is possible to finetune the af on older Pentax models as well, though there is no such item in the standard menu.
...

Thanks for your effort! Didn't know there was such a debug mode. My K100D seems to focus with the usually attached DA 16-45/4 precisely but on some landscape scenes at the wide end I have to push the shutter button half-way several times to hear the AF beep. Maybe some settings are worth playing with.

[pentaxk3user]

On my K110d It used both regular battery's or cr-v3 what are most people using for rechargeable battery's in their cameras ? Once you make the adjustment how do you get out of debug mode ? I can't view a photo once I made a adjustment . If adjust and try to take a photo when I press half way down wait hs is on the screen and the photo is white .Okay edit here for some reason the shutter speed changed . I can take a photo in the debug mode and make adjustments and see the photo it just over laps the words and photo for a few seconds .I you just do the steps over to get out of debug mode by choosing dis . I'm so stupid I didn't scroll all the way down on the instruction above . It worked great . Its so much better now . Thanks Group . I remember now doing this with the k10d but I think I installed a program from a sd card . This was back in 2006 .

[paulh]

Af adjustment on K100D

Thanks for this information. So far I've never needed to adjust the AF, but good to know it's possible!

---------- Post added 09-10-20 at 11:33 AM ----------

what are most people using for rechargeable battery's in their cameras

I've had great success with Eneloops and Rayovac rechargeables over the past 10 yrs.

[glinda]

You aren’t stupid ... takes a little while to get the hang of these electronics things... I still get frustrated with it ... but at least we don’t have to deal with Sony menus .....
thank your lucky stars ....

... oh , or Olympus menus....

On my K110d It used both regular battery's or cr-v3 what are most people using for rechargeable battery's in their cameras ? Once you make the adjustment how do you get out of debug mode ? I can't view a photo once I made a adjustment . If adjust and try to take a photo when I press half way down wait hs is on the screen and the photo is white .Okay edit here for some reason the shutter speed changed . I can take a photo in the debug mode and make adjustments and see the photo it just over laps the words and photo for a few seconds .I you just do the steps over to get out of debug mode by choosing dis . I'm so stupid .

[Racer X 69]

Just received my $ 11.00 K110D with kit lens from Goodwill . I had to wait till the rain stopped . I saw a post on Pentaxians United on facebook about a six-mp club so I took a few quick photos . They are straight out of the camera with no editing except for cropping . The flowers are with the Pentax D-FA 100mm f2.8 and the Grand baby blanket was with the sigma 18-35 f1.8 . . .

Nice photographs.

Now you are going to need to revise your username.

[Simon K]

Just for reference, I've just checked this functionality with both my *ist DS (v.2.02) and my *ist DL2 (v.1.02) and the debug menu can be accessed on both cameras. I didn't feel the need to change anything so left well alone, but it may be of use in the future

Good to hear it works well. Thank you for your feedback.

---------- Post added 09-10-20 at 10:51 AM ----------

Thanks for your effort! Didn't know there was such a debug mode. My K100D seems to focus with the usually attached DA 16-45/4 precisely but on some landscape scenes at the wide end I have to push the shutter button half-way several times to hear the AF beep. Maybe some settings are worth playing with.

Your welcome! As I mentioned with my "normal" lenses I had no problem at all, only when it comes to apertures below f4 like with my f/1.4 lens I noticed an issue.

---------- Post added 09-10-20 at 10:55 AM ----------

Thanks for this information. So far I've never needed to adjust the AF, but good to know it's possible!

Your welcome paulh! Thought I could spread the information just in case it might be helpful for someone.

---------- Post added 09-10-20 at 11:32 AM ----------

On my K110d It used both regular battery's or cr-v3 what are most people using for rechargeable battery's in their cameras ? Once you make the adjustment how do you get out of debug mode ? I can't view a photo once I made a adjustment . If adjust and try to take a photo when I press half way down wait hs is on the screen and the photo is white .Okay edit here for some reason the shutter speed changed . I can take a photo in the debug mode and make adjustments and see the photo it just over laps the words and photo for a few seconds .I you just do the steps over to get out of debug mode by choosing dis . I'm so stupid I didn't scroll all the way down on the instruction above . It worked great . Its so much better now . Thanks Group . I remember now doing this with the k10d but I think I installed a program from a sd card . This was back in 2006 .

I'm glad to hear you could improve your af wiht this method (and as well that you found your way out of the debug mode again ). You are right, with the K10D you will need a modset file to enter debug mode, as it is not built in like it is in the *ist bodies and the K100D.
Edit: Eneloops are great. I bought mine about 10 years ago and still get about 500 shots. When they where new I got around 1000 shots per charge out of them easily.

---

Last edited by Simon K; 09-10-2020 at 11:42 AM.

[Simon K]

K100D + Revuenon 50mm f/1.4 @f/2.0 ISO 800 1/20sec handheld

[carabez]

did not know those lenses could be used on an slr.. dslr..

I Like those 6x7 huge lenses cos' the IQ and the focus thread have a very convenience range what make it easy to nail manual focus. Those are cheap nowadays.

Pentax 6x7 to K Adapter:
Pentax Adapter K for 6x7 Lens (6x7 to K Mount) Reviews - Pentax K-mount Teleconverters and Adapters - Pentax Lens Reviews & Lens Database

[pentaxk3user]

In the micro focus section there are a few numbers to choose from does it matter ? Mine has 0 1 2 or 3 . I picked 0 . Once I make the adjustments its only going to effect the lens thats on there and not all the lens right ? What are the numbers 0 to 3 for ?

[glinda]

Cool, don’t tell anyone else ... keep it a secret ... let me try try this You guys are corrupting me .
Not really ... : )

I Like those 6x7 huge lenses cos' the IQ and the focus thread have a very convenience range what make it easy to nail manual focus. Those are cheap nowadays.

Pentax 6x7 to K Adapter:
Pentax Adapter K for 6x7 Lens (6x7 to K Mount) Reviews - Pentax K-mount Teleconverters and Adapters - Pentax Lens Reviews & Lens Database

---------- Post added 09-11-20 at 07:21 AM ----------

You are brave , attempting this . I would try , as well , but am sure I’d end up by throwing the camera right through a window ....

Out there with a few old lenses ...

In the micro focus section there are a few numbers to choose from does it matter ? Mine has 0 1 2 or 3 . I picked 0 . Once I make the adjustments its only going to effect the lens thats on there and not all the lens right ? What are the numbers 0 to 3 for ?

[Simon K]

In the micro focus section there are a few numbers to choose from does it matter ? Mine has 0 1 2 or 3 . I picked 0 . Once I make the adjustments its only going to effect the lens thats on there and not all the lens right ? What are the numbers 0 to 3 for ?

This is mysterious to me too. I also chose No 0 to adjust and left the other numbers untouched. In my understanding the adjustment is general, but I will try it with another lens to maybe learn more because I had a manual lens attached wich is not recogniced even on the K5, leaving only the option to make a general adjustment.

[djb47]

Zinnia *istDS2/M28 F2.8

[Racer X 69]

In the micro focus section there are a few numbers to choose from does it matter ? Mine has 0 1 2 or 3 . I picked 0 . Once I make the adjustments its only going to eyffect the lens thats on there and not all the lens right ? What are the numbers 0 to 3 for ?

This is mysterious to me too. I also chose No 0 to adjust and left the other numbers untouched. In my understanding the adjustment is general, but I will try it with another lens to maybe learn more because I had a manual lens attached wich is not recogniced even on the K5, leaving only the option to make a general adjustment.

The focus adjustment is only for autofocus lenses. I’m not sure, but I believe that it is a general type of setting, rather than lens specific. The user manual for the camera should be clear in that regard.

[carabez]

The focus adjustment is only for autofocus lenses

IMHO Since Pentax introduce the "floating" sensor via SR there was an issue for a prerfect register distance for the focus plane in the camera. Modern models has a "micro focus adjustment" for one lens (via lens ID) or for all [manual] lenses (register distance).

I regret sold my K10 cos' their blur photos vs clear photos from my DS. ALAS I knew too late about the debug mode to adjust the microfocus. Since then on, I alway adjust the microfocus for ALL lenses in any SR camera and thus I love the *ist Dx