[gatorguy]

Which is funny because my 50-135 AF is hopelessly out of focus when the photo is taken in LV.

That would make it a lens problem then, would it not? Do you have other lenses that focus perfectly with live?

[sebberry]

That would make it a lens problem then, would it not? Do you have other lenses that focus perfectly with live?

I can manually focus it fine in LV but in AF it'll be a bit off, which makes no sense to me as the camera should be driving the lens until it's in focus.

Anyway, I took several photos of this Canada Goose gosling, AFS, center point. (all OVF) Re-focus each time. Each time it back-focused as can be seen from the pebbles. Click through for larger version. Not one was a keeper.



However this little bird presented less of a challenge for the AF system, despite being a little further away and smaller. Several shots of it with that busy pebbly/seaweedy background came out with the bird clearly in the plane of focus.


And I'll let you decide if the focus on the swan's head is acceptable:



My main concern is the inconsistency in hitting focus. I shouldn't have to rack up 10 times the number of shutter actuations to keepers - the thing has a finite lifespan. I should be able to leave a scene knowing that I've caputred some nice sharp photos. Imagine if someone paid me for some dog portraits at the beach (not that that'll happen) and I have to phone them up to say they were all out of focus. And yes, when I manually do a center point AF test at home, the pictures are sharp.

Perhaps Pentax needs to add Wide and Telephoto AF correction instead of just one correction per lens.

[Euan]

Hello, I just picked up a K3 III (and 16-50 PLM) and I've been testing them out during the window when I can still return them (I'll definitely buy the camera, just wanting to make sure that there's no problems with this specific copy)

One thing I've noticed as I've been testing is that when I focus with any point other than the center one, the resulting image is out of focus. When I use the center point, and focus and recompose the image is sharp. But when I compose and move the focus point to the subject then take the photo it is consistently out of focus, without regard to which other focus point I selected. Maybe the ones closest to the center are a little better, but the rest are significantly out of focus.

I'm in AF-S SEL mode. I have focusing disabled on the shutter half-press and I'm using the AF button. I'm making sure I'm waiting on the camera to confirm focus before taking the photo.

I have it set so that when I review the image, it zooms in on where the focus point was so I believe I'm not making a mistake selecting the focus point.

The lens seems good to me: I did some newspaper tests and didn't see any centering defects and everything looked quite sharp across the image.

Is it possible that I have a setting wrong somewhere? Or that I'm missing something else? I've used Pentax cameras for years now (the latest being the K5 II), but I'm pretty unfamiliar with the K3 III and I only have a short window to be able to exchange this unit if it is indeed defective.

(As a side note, I've noticed that pressing the joystick left works great but sometimes pressing it right it doesn't register. The issue seems to come and go and I'm not sure if there's user error somewhere there. Similar for up (works every time) and down (sometimes doesn't register))

Thanks for any help you're able to give me! I hope I'm just missing a setting somewhere: it seems like such a strange problem!

[licht96]

Hello and welcome.

Scroll a little bit down in the global K3 III thread and you will find my ...and your .... topic/thread...here is the link to it:

Can someone check the accuracy/difference of all AF points in AF-S Select - PentaxForums.com

---

Last edited by licht96; 05-17-2022 at 11:10 PM.

[Euan]

Wow, thank you!

It sounds like the problem is quite widespread and is specific to the combination of the K3 III + the 16-50 PLM. I just tried the K3 III with my older 16-50 SDM and yeah it doesn't seem to exhibit the problem.

I certainly feel concerned that this problem hasn't been resolved yet. I'm on the latest firmware, as are others in that thread, and although one of the firmware updates dealt with focusing with this lens it doesn't seem to be resolved.

I feel concerned that maybe there's a hardware problem here that might not be solvable with firmware, and maybe I should return the camera + lens and keep an eye on the issue then rebuy when it's resolved. Both the body and lens are very expensive, and selectable focus points are important to my way of working.

Thank you again for pointing me to this information!

[Paul the Sunman]

Have you tried it in Liveview? Any change?

[licht96]

Please let us discuss in the "original" thread.

LV, other lenses, tolerances, tests charts...are mentioned there, too

[Euan]

Just purchased a K3 III + 16-50 PLM and ran into the same issue randomly while testing. It seemed so weird and random that I believed it was user error until I was pointed to this thread by @licht96. I don't see the issue with my older 16-50 SDM + the K3 III, and focusing in liveview works fine with the PLM.

I'm concerned that since this issue has apparently gone on for so long that it may be a hardware fault in either the camera or the lens, and maybe can't be solved with firmware (there's already been a firmware update addressing focusing with this lens). I'm reminded of the original K5 which didn't focus correctly in the OVF under incandescent light. It wasn't solved until the K5 II/IIs.

I'm going to (sadly) return both the lens and the camera and wait to see what happens with this issue. I use the 16-50 lens almost exclusively, and again almost exclusively work using the OVF + selecting focus points so this really impacts my work.

I was really excited to upgrade: having a silent lens again after using my screwdrive-converted 16-50 SDM, plus all the advances in the K3 III over my old and beat up K5 II really are exciting. I love the new viewfinder, and all the focus points, and the focusing with the PLM lens is so snappy, and the extra stops of ISO are all really exciting advances for me. I love Pentax and have had bodies from the K10D -> K5 II and have a bunch of lenses. I hope that the issue can be solved because the K3 III seems like a fantastic tool otherwise.

Thanks to everyone here for documenting the issue and letting me know I wasn't crazy!

[sebberry]

I don't know how much capacity the camera has for additional firmware features, but Pentax could theoretically add additional AF fine adjustment settings for different zones across the focus screen. Wouldn't have to be for each point obviously but clearly there's an issue.

Maybe we can start with wide and tele AF fine adjustments

[Euan]

Yep, that's totally reasonable to keep it all in one place. I've replied there. Thank you again!

[Not a Number]

Please continue discussion in the earlier thread:

Can someone check the accuracy/difference of all AF points in AF-S Select - PentaxForums.com

[Sandy Hancock]

To make it simpler, the two threads have now been merged

[Settesz]

I'm buying another 16-50 PLM to check if it'll work with my K3iii.
If not maybe it's something with the camera after all?

Just purchased a K3 III + 16-50 PLM and ran into the same issue randomly while testing. It seemed so weird and random that I believed it was user error until I was pointed to this thread by @licht96. I don't see the issue with my older 16-50 SDM + the K3 III, and focusing in liveview works fine with the PLM.

I'm concerned that since this issue has apparently gone on for so long that it may be a hardware fault in either the camera or the lens, and maybe can't be solved with firmware (there's already been a firmware update addressing focusing with this lens). I'm reminded of the original K5 which didn't focus correctly in the OVF under incandescent light. It wasn't solved until the K5 II/IIs.

I'm going to (sadly) return both the lens and the camera and wait to see what happens with this issue. I use the 16-50 lens almost exclusively, and again almost exclusively work using the OVF + selecting focus points so this really impacts my work.

I was really excited to upgrade: having a silent lens again after using my screwdrive-converted 16-50 SDM, plus all the advances in the K3 III over my old and beat up K5 II really are exciting. I love the new viewfinder, and all the focus points, and the focusing with the PLM lens is so snappy, and the extra stops of ISO are all really exciting advances for me. I love Pentax and have had bodies from the K10D -> K5 II and have a bunch of lenses. I hope that the issue can be solved because the K3 III seems like a fantastic tool otherwise.

Thanks to everyone here for documenting the issue and letting me know I wasn't crazy!

[Euan]

Oh interesting -- yeah please let us know here what you find!

[licht96]

To note something again in my started topic: ;-)

I've had 3 (!) K3 III
And two 16-50 PLM.

The camera was returned two times to Amazon (you can say about Amazon what you want - but they are great when you are a good customer and have problems with your purchased products... so thanks to them here).

The second K3 III was in "repair" after Ricoh asked for it. It returned (as mentioned here) after one month only with one word in the paper : calibrated.

Nothing changed!

After my daughter kicked the 16-50 PLM from the table, I was forced to buy a new one (It was a little bit of "luck" that I received money from a patent right after this accident... otherwise I would not have the budget to invest again so much).

Again: no change.

I know: this is still not reliable... but after now so much combination for a private person... I loose my trust in this combination.

Don't get me wrong: I'm still using both... but in the old manner: Spot and recopose. For this the 16-50 PLM is great from optical side! I ve tho old 16-50 as well and I know what I'm talking about.

By the way: I mentioned it many times here... I ve have similar problem with the FA35 2.0 and DFA 50 1.4 wide open on the K3 III... not as prominent as with the new 16-50...but in this way that I don't use other points than center....


And honestly speaking:
I'm not able to discuss all the AF-C threats in this forum, like : why a focus hit or not hit. Or what Auto mode or tracking mode is good for chasing birds...
... since I even struggle with AF-S, I would be not able to say if misfocus is done by no accurate algorithm...or the here in this thread mentioned responsible weakness of outer AF points itself!