[tduell]

I've had a number of occasions recently where my K-3 Mark III has refused to focus.
This has happened with the DFA 150-450 and the DA* 300 lenses.
When attempting to focus there is no response other than a faint sound from within the camera, and rear screen display is OK.
When this happens I have checked the AF switches on camera and lens to no avail.
The only remedy I have found is to switch the camera off, and then on again.
The camera doesn't restart as quickly as normal on these switch-ons, there is a delay as I usually see after fitting a fresh battery.
I'm on firmware v 1.41, and use back button focusing. Focus method is set to AF-C.
There are probably a number of other things to note or check, in order to get a better idea of what is really happening here, but whenever this has happened I've been about to shoot a bird, so I've needed the camera back to normal as quickly as possible.
Anyone else had similar experience?

Cheers,
Terry

[MarkJerling]

Only thing I can think of is, have you set it to back button focus only perhaps?

[ramseybuckeye]

I would carefully clean all the contacts on camera and lenses, most likely camera since it is happening with two lenses.

[wadge22]

Could it possibly be the "stop lens" setting under "action when AF fails"?

[tduell]

Only thing I can think of is, have you set it to back button focus only perhaps?

Thanks.
Yes it is set to only back button, but that's all I use, so not expecting any focus action on shutter button.

Cheers,
Terry

---------- Post added 04-26-22 at 06:07 PM ----------

I would carefully clean all the contacts on camera and lenses, most likely camera since it is happening with two lenses.

Thanks.
That's a possible cause.
I'm pretty fussy about cleaning contacts, always do it on both camera and lens before going out, but could still be the culprit.
I'm not sure that would explain the slow start up after switching back on, that's unusual behaviour.

Cheers,
Terry

---------- Post added 04-26-22 at 06:11 PM ----------

Could it possibly be the "stop lens" setting under "action when AF fails"?

Thanks for the suggestion.
I'd expect to see some attempt by the lens to focus before that happened, but there is no movement at all by the lens.
I'll have to give up on the shot next time it happens and check a few more things, although not really sure what they would be at the moment.

Cheers,
Terry

[Kobie]

Try resetting the camera. That seems to fix all kinds of odd behavior.

[wadge22]

I'd expect to see some attempt by the lens to focus before that happened, but there is no movement at all by the lens.

My thought being that it's still stuck on whatever you were focused on just previously (the distance, anyways, since that previous subject is probably not in frame any more), and has "stopped the lens" there, so isn't trying to focus. You could disprove it either by using quickshift (which should disengage the "stop") when it comes up, or by changing that setting to "drive lens" in advance and hopefully not experiencing it.

Obviously it's just a theory, but since that's a new (and poorly explained) setting, I guessed it could be that.
Good luck, hope it's something simple like that.

[Kobie]

It only happens on those 2 lenses but other lenses work fine?

[tduell]

It only happens on those 2 lenses but other lenses work fine?

I've not had this issue with other lenses, it has only happened a few times and those two lenses are the main ones used.

Cheers,
Terry

---------- Post added 04-26-22 at 08:39 PM ----------

You could disprove it either by using quickshift (which should disengage the "stop") when it comes up, or by changing that setting to "drive lens" in advance and hopefully not experiencing it.

I did try using the quickshift, but made no difference.
I just checked the AF settings, and it was set to 'stop lens' when AF fails. I've now set that to 'Drive lens'.
Thanks for your advice.

Cheers,
Terry

[tduell]

Try resetting the camera. That seems to fix all kinds of odd behavior.

Thanks, I have considered that, but only as a last resort.

Cheers,
Terry

[Paul_R_H]

Thanks, I have considered that, but only as a last resort.

Cheers,
Terry

I've had some strange focussing behaviour on mine. Have been assuming it's dirt on thre AF sensor so will get it cleaned. But how do you do a full factory reset?
Paul

[kypfer]

I've had a number of occasions recently where my K-3 Mark III has refused to focus.
Anyone else had similar experience?
Cheers,
Terry

Mine does it regularly, but not frequently … maybe once every three or four outings.
I use my K-3iii almost exclusively for "birding" and other wildlife so it's almost invariably fitted with my Sigma 150-500mm when the situation occurs.
I simply switch off and on again and get on with it … my previous experience with Ricoh UK has successfully discouraged me from making a warranty claim.
I feel the situation used to occur more frequently than it does now, so maybe the "reliability issues" that have been dealt with in firmware updates have gone some way to reducing the issue.
My "Action When AF Fails" is already set to "Drive Lens" so it's not that, in my instance.
My lens was in use with my KP and K-70 before that for several years and was totally reliable, so I'm disinclined to blame that.
Unfortunately I have no practical option to try something like a 150-450mm or even a different "bigma" to see if the problem disappeared.

[Ole]

Have you checked the two power contacts inside the camera mount and their counterpartson your lenses? They can get misaligned.

[AfterPentax Mark II]

I'm pretty fussy about cleaning contacts, always do it on both camera and lens before going out, but could still be the culprit.
I'm not sure that would explain the slow start up after switching back on, that's unusual behaviour.

Unnecessary cleaning could damage the contacts. You should only clean it when necessary. Slow start up after switching back on could indicate a poor connection between body and lens. After all, it is a "computer" so it will perform security checks and if the contact is disrupted it will repeat that cycle. Next time you have this problem switch the camera off and remove the lens and then switch the camera on. If it shows the same slow start up, you know the problem lies within your camera and you should return it to the seller and let him or her take care of your warranty claim.

[kwb]

Quoting myself in another thread:

Another glitch was that after repeated short bursts (continuous M) with DA* 300 and HD DA 1.4x, suddenly the camera didn't fire. I thought that maybe the camera was writing the data to my card though the access lamp wasn't blinking, waited for 30 sec or so, but it still didn't come back, it even didn't AF. I switched the camera off and back on, and it worked right away. This happened to me a few times before the update, cannot remember the condition, though.

That may or may not be related to your symptom. The quoted post was before v1.41, I might have had had this (my) symptom with v1.41 but I cannot remember, anyway I probably had this problem less than 10 times total.
This happened with DA*300 with HD DA 1.4x and 55-300 PLM, AF mode was AF-C, "action when AF fails" should have been "Drive Lens" as that's the only thing I've ever used. I don't use back button focus. I didn't notice a faint sound from within the camera though it could have been me. Toggling AF/MF switch didn't resolve the issue.