K10 focus check

Hi Guys

I know I have seen (on this forum) ways of checking the autofocus using self printed test pages but can't find the threads/links.

Please could someone kindly remind me where to get the method to check my K10D. I am a little suspicious that it isnt focussing exactly -especially having seen pics taken of the same subject at the same time by a friend using a KM.

The slight softness seems common to all my lenses -including the DA 50-135.

Thanks
Geoff

Here, here, and here.

I've used this Russian software method as it's the only way to do it with the latest K10D firmware and it works fine. No nasties in it. I prefer to use Yvon Bourke's test chart (the third link).

Thanks Peter.

For some reason I'm struggling to get the links to work. I guess its to do with my web browser. I'll try again tomorrow on a different PC.

I appreciate your prompt reply. Hope I can sort it tomorrow.
Cheers
Geoff

All three links work for me in Firefox 3.5 and IE 8.

Hi Geoff, I used the Yvon Bourque charts to test all my lenses with my K10D. It is a long job so allow plenty of time and don`t rush. Repeat each trial at least three times, that way you get used to it and become more proficient. I have left my camera in DEBUG MODE and adjust each time for the lens fitted. Makes a difference you would not believe. The downside is with my Tamron 28 300 which is so far adrift I can`t be bothered with it. Interestingly the same lenses (except Tamron) are spot on with my K20D.

Good luck

Cedric

Hello again Geoff, look at Troubleshooter-DEBUG MODE K10 D. You might be able to gain some more info. Very helpful to me.

Cedric

Hi Guys
Thanks for your really helpful advice. Having printed off the charts and briefly read the other links I can see that the process will take time and should not be rushed.

For my better understanding does any focus issue only effect auto-focus? If I were to use manual focus in my daily photography, might I then get the results one would expect of the camera and the lenses in use?

As it is I nearly always use centre spot auto-focus (with the AF button) and then reframe as required. I can tell the difference between my 50-135 DA* and the Sigma glass but both are not quite "crisp" when compared with shots shown on the gallery here.

Thanks again
Heoff

I have seen this focusing issue before and couldn't figure it out. I thought only the K20 (and now the K7) had this. Can anyone tell me where to find this in the K10 Operators Manual? I didn't even know it existed before the firmware upgrade. Where is it. What part of the program is it in? etc. etc. CHEERS Vic.

It's not in the K10D manual.

There are lots of details at PentaxForums.com... in particular this thread, and this one.

There's an English version of the program that lets you connect to the camera over USB and set/unset debug mode. It's location is given here. Obviously, own risk and all that - but I've tried it and it does work.

Once you get into debug mode, the AF adjustment instructions are here.

Note that unlike the later cameras, there's only one adjustment on the K10D, which presumably applies to all lenses. So it would be worth checking that fixing the AF for one lens doesn't mess it up for others.

Edit: Peter's links have much of this information - the PentaxForums threads seem to be somewhat, maybe largely derived from them.

It's definitely worth doing - many of my pictures, particularly those taken in a hurry, are sharper. (We have a K10D and a GX-10)

It's also definitely worth doing with all your lenses - as there is only one adjustment on the K10D/GX10, I found it useful to be spot on with the long telephoto (Tamron 70-300) and let the wide angle (Pentax 12-24) be a bit out. Luckily, my Tamron and Pentax 43 Limited (the lens that's most often on the Camera) seem to need an identical setting.

Glad to hear that the English language version of the software is working now. I still use the Russian version (with a copy of the tutorial in English)!

I had a very strange experience with the AF adjustment on my K10D that I can neither explain, nor replicate.

As some may have noted, I acquired an FA50 1.4 in excellent condition recently from another forum member, and the first thing I did with it was an AF check, since I have nothing else as fast as 1.4.

I found what appeared to be significant back focusing, detectable at F1.4 but not at F2 or beyond. So I adjusted the AF (40 um required) using the debug menu, and this cured the problem.

I then checked it with one of my other lenses, and didn't notice any change, but for some reason felt uneasy, and undid the adjustment with a view to repeating the process.

Rechecking the AF at F1.4 this time showed no back focus at all, and equally I couldn't see any with a couple of other lenses. Having used the FA50 for real now, a couple of times, I have no reason to think there's anything the matter with it.

Now I know all about the "dismantle, clean, reassemble" technique for miraculously fixing unexplained problems with all kinds of devices, but doing, and then undoing an AF adjustment to cure a problem, does seem a bit strange to me.

It was all on a tripod, 2s delay, green hexagon focus confirmation, centre AF point selected and all that... so no obvious reason for completely cocking up the initial check, and since I tend to work on the assumption that unreproducible problems don't exist, at least until they become reproducible, I'm not overly troubled about it.

I report it just in case it rings a bell with anyone.

Did I read a review or a thread commenting that the FA50 1.4 has a very short depth of field wide open and is therefore focus critical anyway.

Well it does, yes, which is why you want to be sure that it focuses where you think it does, and not an inch or so behind that.

That's why I went looking for AF issues at F1.4. With the exceptionally shallow DOF you might expect that you'd see back or front focusing that was masked by a deeper DOF with other lenses, or the same lens at narrower apertures.

It wasn't a surprise to find some, and it wasn't a surprise to see it go away at F2.

What was a surprise, was that taking out the adjustment I'd just put in to cure it did not put back the BF I'd seen originally.

It's a bit like it would be a surprise, if you wore glasses for five minutes to cure an obvious short-sightedness, then took them off and discovered that your uncorrected vision was now perfect.

There's definitely variability in the equipment and in the process (tripod position, distance, ambient temperature, dust in the lens mount, etc.).

It is important to switch the SR to off when on a tripod (now I'm not suggesting for one minute...:blush - I wonder if this could affect the results if SR was left on? I suppose it depends on how the SR moves the sensor...:

Not sure what you're getting at with this point, sorry.

[quote="El Dingo"]It is important to switch the SR to off when on a tripod (now I'm not suggesting for one minute...:blush - I wonder if this could affect the results if SR was left on? I suppose it depends on how the SR moves the sensor...:[/quote]SR is off with all the remote and delayed modes, regardless of the position of the SR switch, so I can't see how SR is at all relevant here.