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09-06-2007, 08:30 AM   #16
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I am becoming a little bit worried... your lenses were not adjusted to the body as my local service described they could do?

If this doenst work, I am seriously consider bailing out... it is even easier now I have sold most of my Pentax lenses. But preparation for a change wasnt the purpose of that action.

09-07-2007, 09:22 AM   #17
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QuoteOriginally posted by ennacac Quote
FWIW I had issues with BF with my K10D using my FA* lenses and I finally sent it to Pentax who replaced the camera body with a new one. The new one was all over the place with BF/FF issues also and sometimes even would give me the correct focus. It was not reliable, so I had it looked at and adjusted to Pentax specs, but it still would be off by just a bit on occasion either front or back, which at shallow DOF gave me soft images
I finally gave up and sold it and am now using my DS while waiting to see what Pentax comes out with next before I decide what to do about a new camera. I found the K10D to be a work in progress and not a camera I could rely on 100% of the time like I can the DS.

When it worked it was great, but I do wildlife work and couldn't count on the K10D doing what it should with shots I could not do over focus wise. I decided two cameras, the same problem, I don't want the K10D any longer and it went away.

I would like to stick with Pentax, but they have to come out with something new that I can use since I need to upgrade from my DS sometime soon.

Tom
You know that is the same problem I have with my K100D and 50-200 Pentax kit lens (came as camera and two af lenses). When shooting birds I get acceptable results if they are within 20 or 30 feet of the 50-200 lens. Camera often does set the correct focus point. But when the subject is far away, the whole frame goes to "instamatic" quality. I have labored to try and work around it, manual focusing is not really possible for most of the action shots. I think mine is either over focusing, as I have seen in some bridge cameras, or just not very good at the 200mm focal length.

I posted a query and one person did say he had the exact same problem. All but that one person seemed to think it was me and not the camera/lens, I disagree as I have used other similar cameras which dramatically better results (Canon DSLR and Sony bridge cameras). I must say that one person was downright rude and missed the point of my question entirely, but that is what forums are like. Guess I expected too much.

Am selling that lens and possibly body with 18-55 kit lens. I have gotten some really nice shots from the K100D using the 18-55 lens, but again usually when the subject is not distant. I just don't think the K100D has enough growth room for me. I bought an entery level SLR and should have foregone the telephoto zoom and gotten a better camera and basic lens. I don't think digital photography is like film photography where you could buy a entry level body and still get good results given a decent lens. Live and learn. In that regard, Pentax's comparison of the K100D to the famous K1000 doesn't hold water.

BTW, my Panasonic Lumix 6 mp compact camera isn't that much worse in picture quality from the K100D for scenic shots. But it has no manual controls and awful white balance. Still, will keep it for a travel camera and consider a Nikon or Canon DSLR. Would stay with Pentax, but second time around will choose one that I have hands on experience with. Sister has the Rebel XTI and it works great. Nikon D40X is interesting, but don't know anyone who has one.

Last edited by Justed; 09-07-2007 at 09:26 AM. Reason: correct typing errors
09-07-2007, 09:35 PM   #18
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Those (K10D) AF errors can be a body problem but also a lens problem. For the technical details behind why it is so, see my old articles:-

RiceHigh's Pentax Blog: AF Accuracy's Dependency on Lenses and Yellow Light

RiceHigh's Pentax Blog: Focus Calibrations for (Pentax) (D)SLR Bodies and Lenses

Besides, I recommend also before you upgrade to firmware 1.30, you should try the AF accuracy for your new Star lens first, because after the upgrade and SDM is engaged, you *may* get more out-focused photos:- RiceHigh's Pentax Blog: SDM = More AF Errors?

Then, if problem persists and you want to get back to the earlier version, it would involve more works and trouble to get it back:

RiceHigh's Pentax Blog: How to Get Back to an Older Version of the Firmware?

Finally, would you tell us if the older firmware of K10D will drive the Star lens NON-ultrasonically? Pls verify this and let us know. TIA.

QuoteOriginally posted by Harald Quote
Hello

My K10D came just from local service. It didnt focus correctly with my AF lenses and it was serviced as warranty work.

I thought that it was an body malfunction. Severe back focus. I noticed this after buying two weeks ago Sigma 70-200/2.8 DG lens. I have been using MF lenses lately...

They found some degree of back focus and adjusted it.... well... it backfocuses little less now, but it is not gone. It still backfocuses quite much. But less now than before service.

This is not lens related because it is same with all my AF lenses. All of them are older screw focus type.

There has been much discussion about backfocusing issues in DPRewiev.
I updated the firmware to 1.3 some time ago because my DA* 16-50 should be here any day.

It seems that this backfocus issue CAN be related to 1.3 firmware becaus as far as I can remember Af was much better some months ago when I last time used AF....

Any thoughts?
09-08-2007, 12:22 AM   #19
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version 1.2 WILL focus the da* lenses using a conventional screw drive. I kept the old version so that I could compare focus speeds.

I have said it again and again, they used a motor with too large of a step size (high torque motor geared low), and sacrificed focus precision in doing so. I would FAR prefer a slower focus camera.

Bottom line is that my old digital rebel focused better than my k10d, and yes, that is a big insult.

Still love my pentax glass and hope pentax gets it right with the next body.

QuoteOriginally posted by RiceHigh Quote
Those (K10D) AF errors can be a body problem but also a lens problem. For the technical details behind why it is so, see my old articles:-

RiceHigh's Pentax Blog: AF Accuracy's Dependency on Lenses and Yellow Light

RiceHigh's Pentax Blog: Focus Calibrations for (Pentax) (D)SLR Bodies and Lenses

Besides, I recommend also before you upgrade to firmware 1.30, you should try the AF accuracy for your new Star lens first, because after the upgrade and SDM is engaged, you *may* get more out-focused photos:- RiceHigh's Pentax Blog: SDM = More AF Errors?

Then, if problem persists and you want to get back to the earlier version, it would involve more works and trouble to get it back:

RiceHigh's Pentax Blog: How to Get Back to an Older Version of the Firmware?

Finally, would you tell us if the older firmware of K10D will drive the Star lens NON-ultrasonically? Pls verify this and let us know. TIA.


09-08-2007, 04:35 AM   #20
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QuoteOriginally posted by SloPhoto Quote
version 1.2 WILL focus the da* lenses using a conventional screw drive. I kept the old version so that I could compare focus speeds.
Oh, really thanks for your info! That's what I want to confirm!

QuoteQuote:
I have said it again and again, they used a motor with too large of a step size (high torque motor geared low), and sacrificed focus precision in doing so. I would FAR prefer a slower focus camera.
Just curious to know how to you know that is the ROOT cause?

QuoteQuote:
Bottom line is that my old digital rebel focused better than my k10d, and yes, that is a big insult.
Yes. I would not be very surprised for my Pentax not as accurate as my 5D. But if the K10D is worse than the Digital Rebel, that would be a real shame!

QuoteQuote:
Still love my pentax glass and hope pentax gets it right with the next body.
Me 2! But since you've suggested that it is a lens issue for the SDM AF inaccuracy, how can a new body cures the problem? :-)
09-08-2007, 10:31 AM   #21
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QuoteOriginally posted by RiceHigh Quote
Oh, really thanks for your info! That's what I want to confirm!
QuoteQuote:
Just curious to know how to you know that is the ROOT cause?
To preface, I am speaking of the in body motors.

I do not, but I have experience making software to control wafer steppers, where we use motors to move the stage(what the wafer sits on). In this realm, there is no mechanical system precise enough, so you get to do all sorts of funky stuff to precisely position the dang thing. The larger the step, the longer the linkage, etc, the more difficult it is. Taking a system and software designed for a small step and throwing larger steps into it = failure exactly as we have seen with the k10d. That is why it is my assumption.

Why nobody has thrown an SDM motor in the body, I do not know. Possibly it is the cost, or they are worried the step sizes will be smaller than the slop in the screw drive system (this is actually not a problem at all, simply requires different control algorithms).

QuoteQuote:
Yes. I would not be very surprised for my Pentax not as accurate as my 5D. But if the K10D is worse than the Digital Rebel, that would be a real shame!
This is ONLY true in very low lighting conditions. Everywhere else, the k10d mops the floor with my 300d.


QuoteQuote:
Me 2! But since you've suggested that it is a lens issue for the SDM AF inaccuracy, how can a new body cures the problem? :-)
[/QUOTE]

Ahh, as for the focusing inaccuracies with an SDM motor, my bet is that the cause is the algorithms. Piezo motors generally have small step sizes (not necessarily precise, but better than a conventional motor within this realm) It seems that the 50-135 is far better than its wider angle cousin. This might make it harder, as the focus spots are IMO quite damn big, and on a wider angle they will see more angular coverage. Then again, this is just a WAG.
09-09-2007, 07:23 AM   #22
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I think your "guess" is in fact quite sensible enough. Precision and speed are always contradictory factors for a certain system as a whole, which has a certain overall performance. Your example of wafer stepping motor control is a good one as the algorithm is one of the key things to count for optimal feedback and control of the system with optimal performance and acceptable accuracy within all the constraints, including the physical limitations of the moving parts and motors (as well as the resolution(s) of the feedback sensor(s) and etc.).

Afterall, I hope Pentax can cure the problem by re-writing a better algorithm. Otherwise, the hardware needed to be improved/debugged.

QuoteOriginally posted by SloPhoto Quote
To preface, I am speaking of the in body motors.

I do not, but I have experience making software to control wafer steppers, where we use motors to move the stage(what the wafer sits on). In this realm, there is no mechanical system precise enough, so you get to do all sorts of funky stuff to precisely position the dang thing. The larger the step, the longer the linkage, etc, the more difficult it is. Taking a system and software designed for a small step and throwing larger steps into it = failure exactly as we have seen with the k10d. That is why it is my assumption.

Why nobody has thrown an SDM motor in the body, I do not know. Possibly it is the cost, or they are worried the step sizes will be smaller than the slop in the screw drive system (this is actually not a problem at all, simply requires different control algorithms).



This is ONLY true in very low lighting conditions. Everywhere else, the k10d mops the floor with my 300d.


Ahh, as for the focusing inaccuracies with an SDM motor, my bet is that the cause is the algorithms. Piezo motors generally have small step sizes (not necessarily precise, but better than a conventional motor within this realm) It seems that the 50-135 is far better than its wider angle cousin. This might make it harder, as the focus spots are IMO quite damn big, and on a wider angle they will see more angular coverage. Then again, this is just a WAG.[/QUOTE]
09-09-2007, 07:39 AM   #23
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QuoteOriginally posted by Harald Quote
Hello

My K10D came just from local service. It didnt focus correctly with my AF lenses and it was serviced as warranty work.

I thought that it was an body malfunction. Severe back focus. I noticed this after buying two weeks ago Sigma 70-200/2.8 DG lens. I have been using MF lenses lately...

Any thoughts?
I have the same problem with my K10d with the Sigma 200mm f2.8. What I've found is its more of a lighting issue for mine. If I shoot in bright light or very well lit indoors, its fine. If I shoot in low light outdoors, or indoors, it starts to back focus about 75 percent of the shots.

09-09-2007, 06:53 PM   #24
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EDIT - this information only works for K10D firmware 1.1 -
the instructions do NOT work for later firmware versions
that is probably the reason the original web page/blog is no longer available.

I am a little hesitant posting this -
there used to be an article (blog) on the web that was titled -

Pentax DSLR focus correction

the url was -

(http://)roman.blakout.net/?year=2007&blog=20070219132433

(DON'T click on this link as it is not valid -
I put the http:// in parentheis to reveal the actual url text -
otherwise the posting editor substitutes this link -

Roman Melihhov 2007; photos (all categories) )

(obviously the article is no longer there -
I do not know the reason for why it is no longer available -
I saved a copy of this page when it was still on-line, around the end of March/2007)

However I will quote (copy/paste) some relevant sections -
(Disclaimer - I am only copy/pasting the information "as-is" -
and cannot vouch for any accuracy/inaccuracies,
any use is entirely at your own risk)

QUOTE:
Pentax DSLR focus correction


If your Pentax *istDL v1.03, *istDL2, *istDS v2.02, *istDS2 v1.02, K100D v1.02, K110D v1.02 or K10D v1.10 is not focusing right, there's remedy for your camera that comes with newest firmware update. Get your latest firmware update first from the http://www.pentaximaging.com/customer_care/software_firmware?sfFlag=f and then follow the steps below. Prior to changing mode to debug, I switched to central AF point. It's easier to see what you're focusing on. Grid value on the following examples - 0.1 inches (2.54mm). Photographed at 45˚ angle, a step of the ruler = 5um AF correction.

END QUOTE

QUOTE:
K10D series DEBUG STEPS

1. Your K10D' firmware version must be 1.10.

2. Test shot for focus trouble.

3. Turn the camera OFF.
While pressing [PLAY]+[OK], Turn the camera ON.
You can see firmware version on LCD screen.

4. Firmware version is appeared,
then press [Fn]->[Fn]->[INFO]->[MENU] within 5 seconds.
You get service menu!!!

5. by pressing [right key],change DEBUG MODE [DIS] to DEBUG MODE [EN].
then press [OK].
(save and LCD will be black out)

6. Press [MENU] and go to SETUP tab.





then, Press [^Up key], you can see TEST MODE.

7. Select AF TEST menu. now you have AF correction menu.
If you have Front-focusing, reduce the value.
If you have back-focusing, increase the value.
after adjust some value, press [OK] and quit out of setup menu.

8. TEST for focus, find out that focus is correct.
(repeat this from 6 for correct focus.)
9. Go to service menu(step 3,4).
change DEBUG MODE [EN] to DEBUG MODE [DIS].
then press [OK]. (save and LCD black out)

I used ruler photographed from macro distance at 45˚ angle. Autofocused precisely on a 4.5 line (maybe a little above. Picture below comes with corrected AF point, picture above appear backfocused. If your camera is front-focusing, reduce the value, if it's backfocusing - increase the focus correction value.

END QUOTE

Disclaimer - I cannot vouch for the accuracy or inaccuracy of this - any use is entirely at your own risk.

Last edited by UnknownVT; 09-10-2007 at 08:13 AM. Reason: Information only works for firmware 1.1
09-10-2007, 07:10 AM   #25
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UnknownVT,

Thanks for the info but that issue was covered by Pentax and it was previously mentioned above in one of my posts.

"I found an article on dpreview about a key selection sequence for getting into the debug routine of the K10 firmware 1.1 and actually being able to adjust the front/back compensation. Pentax has since disabled it in later fw releases. With a very important wedding shoot within two weeks, I called Pentax tech and got transfered to 2nd tier at CO. I was hoping that the tech guy would agree to help me out over the phone and give me a way of adjusting the f/b in the firmware. Of course, that's out of the question...V-8 moment. "

Good researching though. Wish more people would before posting.

Take Care,

Chuck
09-10-2007, 07:55 AM   #26
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QuoteOriginally posted by Chuck Lee Quote
that issue was covered by Pentax and it was previously mentioned above in one of my posts.

"I found an article on dpreview about a key selection sequence for getting into the debug routine of the K10 firmware 1.1 and actually being able to adjust the front/back compensation. Pentax has since disabled it in later fw releases. ...."
Thanks for that.

I just tried it on my K100D (not 10) with latest firmware 1.02 -
and the instructions/key-sequence for the K100D do work and allows me to get to AF adjustment.

The unavailablity of AF adjustment for the K10D may well be the reason why that page/blog is no longer available.

However - there probably has to be a way to adjust the AF on the K10D -
don't the (Pentax) techs have to be able to do it?

EDIT to ADD -

via this page on RiceHigh's Pentax Blog -
this link has instructions on how to adjust focus by opening the camera and adjusting screws.....

Re: I have fixed my front focus problem - how to: Pentax SLR Talk Forum: Digital Photography Review

EDIT #2 -

Doing a little more searching I found via another page on RiceHigh's Pentax blog -
with a link back to a thread in this forum with the AF adjustment instructions (dated 2/11/2007) -

https://www.pentaxforums.com/forums/pentax-dslr-discussion/3158-k10d-service-menu-af-adjust.html

remember these instructions only apply to K10D firmware 1.1 -
later firmware versions on the K10D no longer have the AF adjust.
The later posts with the instructions for the K100D do work with K100D firmware 1.02 (I have accessed it)

Last edited by UnknownVT; 09-10-2007 at 08:58 AM. Reason: typos + added info
02-09-2010, 09:30 PM   #27
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My K10D got back focus, so I corrected it via debug. As I had upgraded it to firmware 1.3, so I had to used the hacked software to return to 1.10 before the correction. During my correct, i found that the K10D focus very slowly.

I think I had turn the MF function on during the time of correct and then turned back to AF.

After that, I cant do AF, only can MF. I checked and the button focus put at AF-S but on the view finder, it shows MF.

How could I change the camera back to AF?

Thanks.
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