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04-07-2014, 11:56 AM   #1
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K10D - Autofocus and Aperture strange behaviour

Hi, just wondered if anyone has experienced something similar or can suggest a fix for this "problem".

I have a K10D that will (not):
- with a Pentax DA 18-55mm / Pentax DA 50-200mm WR (or any other A, F, FA - even though I've not tried every single one of the lenses) when set to any mode (P, Sv, Tv, Av, Tav, M, B, X) and any AF (AF.S, AF.C and even MF) take picture, the metering works, but it will ignore the half press or full or DOF preview, but when I enable the Aperture Ring in C menu it will autofocus, and will react to half/full press and even makes seems to actuate the DOF preview, but the aperture will stay wide open; AF.S, AF.C, MF works as it should, it's same with all modes, shutter speed will adjust according to aperture set but when the picture is taken the aperture stays open, shutter is according to metering and EXIF has these values recorded as such

- and the only exception to the above seems to be power zoom lenses (only have one, Pentax-FA 1:3.5-4.7 28-80, but i guess it would be same with any pz lens) - this lens works as it should with any mode, any af setting and with aperture ring setting disabled, it will AF, reacts to half/full press and DOF works as it should, basically this lens works in the full auto mode, mine is missing the selector switch so not sure what is the default setting on the lens itself, but it won't work in the power zoom mode (that to my understanding could be due to the 1.31 firmware) but other than that it works

I've tried to clean contacts on lenses and he camera and also know the lenses (DA, F) work fine on mine K20D so the problem must be with the K10D but i just cannot find any information what could be the reason behind this strange behaviour if the power zooms works in auto, then everything should

I'll appreciate any suggestions as to what to try to fix this or at least would like to know what could be the reason behind this so all ideas are welcome (other than that I don't mind, I do like to have it as M lens camera only, but at the same time I'm very curious)

thank you!

04-07-2014, 12:35 PM   #2
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QuoteOriginally posted by lubosh.occ Quote
Hi, just wondered if anyone has experienced something similar or can suggest a fix for this "problem".

I have a K10D that will (not):
- with a Pentax DA 18-55mm / Pentax DA 50-200mm WR (or any other A, F, FA - even though I've not tried every single one of the lenses) when set to any mode (P, Sv, Tv, Av, Tav, M, B, X) and any AF (AF.S, AF.C and even MF) take picture, the metering works, but it will ignore the half press or full or DOF preview, but when I enable the Aperture Ring in C menu it will autofocus, and will react to half/full press and even makes seems to actuate the DOF preview, but the aperture will stay wide open; AF.S, AF.C, MF works as it should, it's same with all modes, shutter speed will adjust according to aperture set but when the picture is taken the aperture stays open, shutter is according to metering and EXIF has these values recorded as such

- and the only exception to the above seems to be power zoom lenses (only have one, Pentax-FA 1:3.5-4.7 28-80, but i guess it would be same with any pz lens) - this lens works as it should with any mode, any af setting and with aperture ring setting disabled, it will AF, reacts to half/full press and DOF works as it should, basically this lens works in the full auto mode, mine is missing the selector switch so not sure what is the default setting on the lens itself, but it won't work in the power zoom mode (that to my understanding could be due to the 1.31 firmware) but other than that it works

I've tried to clean contacts on lenses and he camera and also know the lenses (DA, F) work fine on mine K20D so the problem must be with the K10D but i just cannot find any information what could be the reason behind this strange behaviour if the power zooms works in auto, then everything should

I'll appreciate any suggestions as to what to try to fix this or at least would like to know what could be the reason behind this so all ideas are welcome (other than that I don't mind, I do like to have it as M lens camera only, but at the same time I'm very curious)

thank you!
So you're getting incorrect exposures when selecting a stopped-down aperture setting? A few samples would help us diagnose the issue (use the attachment system as then we'll be able to see the EXIF).

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04-07-2014, 01:06 PM   #3
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QuoteOriginally posted by Adam Quote
So you're getting incorrect exposures when selecting a stopped-down aperture setting? A few samples would help us diagnose the issue (use the attachment system as then we'll be able to see the EXIF).
no, sorry that is not really an issue, the problem is that any of the lenses I have DA, F, A won't work without the aperture ring being enabled in Custom Menu, but the power zoom lens does work … i know the problem is not the lenses because they all work as they should on k20d, so it's the k10d, but i don't understand how is it possible if something is causing the DA, F, A lenses not to work(no reaction to shutter being pressed, no af confirm in the viewfinder) and the FA power zoom works fine

stopped-down aperture setting works as it should, but it's not the normal mode of operation i would like to use with DA, F, A lenses

sorry if the question is a bit confusing, it is a confusing problem

---------- Post added 04-07-14 at 01:15 PM ----------

- i can use any lens with the aperture ring (M, A, F, FA), when i enable the Aperture ring in Custom menu, but only in M mode, with stopped-down metering
04-07-2014, 01:25 PM   #4
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QuoteOriginally posted by lubosh.occ Quote
- i can use any lens with the aperture ring (M, A, F, FA), when i enable the Aperture ring in Custom menu, but only in M mode, with stopped-down metering
If this is what you're experiencing, then it's perfectly normal. Pentax DSLRs (unlike film cameras) cannot sense the position of the aperture ring, so when it's not set to "A" the metering has to be performed as if your lens were fully manual:
https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html


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04-07-2014, 02:08 PM   #5
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oh, ok, i thought that da, f, fa lenses should work with autofocus without enabling 'use aperture ring' in the custom menu, i cannot even find any da lenses that would have the aperture ring, does that mean that the da lenses are not supposed to work with dslr cameras?

sorry for that, i know you're trying to help, but i feel you're missing what my question was :-) ... lets pretend for a minute that i know what i'm talking about, i'm not trying to figure out the normal mode of operation ... i'll put the issue in the most simplistic way i can

i've got the k10d on with just the normal settings, like it was just reset to default, af mode is af.s, left selector is on p, i've got the 18-55mm lens pentax-da II, the meter works i can se it calculate the a and t values, but when i pres the shutter nothing will happen, af won't work, dof wont work, if i change the af selector to mf the shutter would still not take a picture

now if i simply swap the lens for pentax-fa 28-80mm power zoom everything works, af, dof, shutter as normal

the lenses are fine, both work on a k20d, i've already cleaned the contacts on lenses and camera, but that has no effect

is there any explanatinon that makes sense as to why

---------- Post added 04-07-14 at 02:12 PM ----------

one works and the other not? is there anything so different that would make the power zoom to work even thought theres is something wrong with the camera that would affect the da lens?
04-07-2014, 03:47 PM   #6
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QuoteOriginally posted by lubosh.occ Quote
i thought that da, f, fa lenses should work with autofocus without enabling 'use aperture ring' in the custom menu
One thing at a time, eh?
  • Make sure your battery is fully charged*
  • Reset the camera to factory settings (menu/setup/reset)
  • Turn the camera off
  • Mount your DA 18-55 kit lens
  • Confirm that AF is set to AF-C
  • Turn the camera back on with lens cap off
  • Select "P" mode
  • Confirm that both shutter speed and aperture are displayed on the top LCD
  • Bring the viewfinder to eye and half-press the shutter release on a near subject
  • Confirm that the AF motor engages (you should hear it) and that an attempt to focus is made
  • Repeat the preceding two steps with a more distant subject
How are we doing? Does everything work as expected? If so, repeat the last six steps using a sampling of your FA and F series lenses taking care to make sure that the aperture ring is in the "A" position.

Still good? If so, we have confirmed that the basic functionality, including AF is at least attempting to work with the lenses that support the full range of the camera's functions. Just for jollies you might also want to try the above with one or more of your A-series lenses too.

If everything to this point is working, your K10D is probably nicely functional. If not, it is very likely broken and to the best of my knowledge I have not read of any similar failure of a K10D that is user addressable in the time that I have been involved with this forum.

Good luck and please forgive me if my comment is overly pedantic.


Steve

* One thing to consider is that the original equipment batteries of both the K10D and K20D bodies are nearing their practical end of life. Lithium cells lose their ability to deliver full voltage or accept full charge with age, regardless of use.

Last edited by stevebrot; 04-07-2014 at 03:52 PM.
04-07-2014, 07:10 PM   #7
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The way I read it he does not get AF unless the aperture ring is enabled in the menu. Have not heard of this problem but I am wondering why you would not want it enabled anyway? Sounds as though something is amiss as the power zoom af's as normal. Don't by chance have the shutter button turned off for AF? I guess that would still not explain why the shutter would not fire unless you are set to focus priority also? Just some musings.
04-07-2014, 09:11 PM   #8
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QuoteOriginally posted by rwingsfan Quote
The way I read it he does not get AF unless the aperture ring is enabled in the menu.
That and all the details of the description is why I phrased my answer the way I did. Too much noise in the channel.


Steve

04-07-2014, 09:44 PM   #9
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QuoteOriginally posted by stevebrot Quote
One thing at a time, eh?
  • Make sure your battery is fully charged*
  • Reset the camera to factory settings (menu/setup/reset)
  • Turn the camera off
  • Mount your DA 18-55 kit lens
  • Confirm that AF is set to AF-C
  • Turn the camera back on with lens cap off
  • Select "P" mode
  • Confirm that both shutter speed and aperture are displayed on the top LCD
  • Bring the viewfinder to eye and half-press the shutter release on a near subject
  • Confirm that the AF motor engages (you should hear it) and that an attempt to focus is made
  • Repeat the preceding two steps with a more distant subject
How are we doing? Does everything work as expected? If so, repeat the last six steps using a sampling of your FA and F series lenses taking care to make sure that the aperture ring is in the "A" position.

Still good? If so, we have confirmed that the basic functionality, including AF is at least attempting to work with the lenses that support the full range of the camera's functions. Just for jollies you might also want to try the above with one or more of your A-series lenses too.

If everything to this point is working, your K10D is probably nicely functional. If not, it is very likely broken and to the best of my knowledge I have not read of any similar failure of a K10D that is user addressable in the time that I have been involved with this forum.

Good luck and please forgive me if my comment is overly pedantic.


Steve

* One thing to consider is that the original equipment batteries of both the K10D and K20D bodies are nearing their practical end of life. Lithium cells lose their ability to deliver full voltage or accept full charge with age, regardless of use.
Hi Steve,

it's ok up to the point with half press (3rd point from the bottom of the list) as nothing happens from that point on, no motor sound with da or f lenses, and won't get the focus confirmation with any A lens either, tried with 3 different batteries, all fully charged (pulled 1 from the k20d)

but doing following the same checklist and using the fa power zoom, will pass ok through all the points

thank you
04-07-2014, 11:47 PM   #10
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QuoteOriginally posted by rwingsfan Quote
The way I read it he does not get AF unless the aperture ring is enabled in the menu. Have not heard of this problem but I am wondering why you would not want it enabled anyway? Sounds as though something is amiss as the power zoom af's as normal. Don't by chance have the shutter button turned off for AF? I guess that would still not explain why the shutter would not fire unless you are set to focus priority also? Just some musings.
Hi rwingsfan,

you got it right, the reason why having the aperture ring enabled in the custom menu all the time is not a solution, is because:

- with "use aperture ring" enabled in custom menu, and the DA lens, the AF works fine, but the camera will always use the stay wide open aperture (even though i can hear the actuator moving), and same for the F lens, and same for the A lens(the A has no af but the aperture will not close), the F and A lenses will work only in the full manual (M) mode … thats when the aperture will close as it should

---------- Post added 04-07-14 at 11:57 PM ----------

QuoteOriginally posted by lubosh.occ Quote
Hi rwingsfan,

you got it right, the reason why having the aperture ring enabled in the custom menu all the time is not a solution, is because:

- with "use aperture ring" enabled in custom menu, and the DA lens, the AF works fine, but the camera will always use the stay wide open aperture (even though i can hear the actuator moving), and same for the F lens, and same for the A lens(the A has no af but the aperture will not close), the F and A lenses will work only in the full manual (M) mode … thats when the aperture will close as it should
sorry forgot to put at that point the aperture is set with the ring on the lens, so basically the DA lens will always stay wide open that made me think it could be a problem with the pin that actually communicates the aperture but then again why would it work with the power zoom lens? i guess it's using the same pin, and the only difference is the two contacts that power it's built in motor at that point i've no idea what could be causing this

last thing i thought of was to downgrade the firmware and re-update it .. not sure if the firmware could be corrupted in a way it would affect this

thank you
04-08-2014, 07:45 AM   #11
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QuoteOriginally posted by lubosh.occ Quote
but doing following the same checklist and using the fa power zoom, will pass ok through all the points
Well, I guess that means that all your lenses except the FA power zoom are broken, except for when used on your K20D. Either that or your K10D has a fault that is magically* not present with the FA power zoom.

BTW, you did reset the camera to default (factory) settings, right? Is it safe to assume that the AF button is also non-functional?


Steve

* Magic does happen, but usually it is because of a glitch somewhere.

---------- Post added 04-08-14 at 08:02 AM ----------

QuoteOriginally posted by lubosh.occ Quote
sorry forgot to put at that point the aperture is set with the ring on the lens, so basically the DA lens will always stay wide open … that made me think it could be a problem with the pin that actually communicates the aperture …
A couple of points regarding the K10D:
  • There is no pin that communicates aperture per se, just a pair that indicate maximum and minimum for the lens mounted and a data pin that may (depending on lens mounted) communicate current focal length.
  • Your K10D AF system should function regardless of the generation of lens mounted, the presence of an aperture ring, or the position (if present) of the aperture ring. In other words, it is basically the same as your K20D.
  • This is probably not firmware related unless you have been using a hacked binary
  • Reverting to an earlier firmware version is not usually possible. When done, it requires a few small hacks to the binary.
  • Since all of your lenses work fine on the K20D, they are not the source of the problem. You can do your testing with a single lens. I would suggest your 18-55 kit since it is current generation.
  • There is only one feature of the K10D AF system that should be sensitive to the type of lens mounted. That feature is catch-in-focus which requires a conductive base.
Good luck.


Steve

Last edited by stevebrot; 04-08-2014 at 08:09 AM.
04-08-2014, 09:31 AM   #12
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...

QuoteOriginally posted by stevebrot Quote
Well, I guess that means that all your lenses except the FA power zoom are broken, except for when used on your K20D. Either that or your K10D has a fault that is magically* not present with the FA power zoom.
it's definitely the second one, the fault is magically not preset with the FA lens


QuoteOriginally posted by stevebrot Quote
BTW, you did reset the camera to default (factory) settings, right? Is it safe to assume that the AF button is also non-functional?
i did try the reset, no change, AF button only works same as shutter, it's ok with power zoom, no action with DA

QuoteOriginally posted by stevebrot Quote
Steve

* Magic does happen, but usually it is because of a glitch somewhere.

---------- Post added 04-08-14 at 08:02 AM ----------



A couple of points regarding the K10D:
  • There is no pin that communicates aperture per se, just a pair that indicate maximum and minimum for the lens mounted and a data pin that may (depending on lens mounted) communicate current focal length.
  • Your K10D AF system should function regardless of the generation of lens mounted, the presence of an aperture ring, or the position (if present) of the aperture ring. In other words, it is basically the same as your K20D.
  • This is probably not firmware related unless you have been using a hacked binary
  • Reverting to an earlier firmware version is not usually possible. When done, it requires a few small hacks to the binary.
  • Since all of your lenses work fine on the K20D, they are not the source of the problem. You can do your testing with a single lens. I would suggest your 18-55 kit since it is current generation.
  • There is only one feature of the K10D AF system that should be sensitive to the type of lens mounted. That feature is catch-in-focus which requires a conductive base.
Good luck.


Steve

hmm so the AF doesn't work with DA in normal mode either, it will not confirm focus, only after the use aperture ring is enabled it will confirm focus

well i don't know about the firmware this is a second hand, i bought it with this issue, but the fact about the power zoom wash't known to the seller as he had not had any power zoom lenses to try this, it reports as 1.31 firmware, i am aware of the hack procedure with the modified binaries, but i don't think there is any actually hacked firmware (in a sense that would include some improvements or new functions to the original firmware) just that some ppl reverted back to 1.20 to be able to use sdm, but i was thinking since i don't have a way to know what is actually loaded that it would be worth a try in the past the solution was usually the one thing not tried even when it made no sense to try at all at first thats the magic again

catch-in-focus works as well

thank you as i said, i don't mind using the camera as is since i've got the 20 that works fine with new lenses, but i'm very curious as this problem just doesn't make sense

thank you
04-08-2014, 09:37 AM   #13
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QuoteOriginally posted by lubosh.occ Quote
catch-in-focus works as well …
catch-in-focus works? Now that is a puzzle.

Reverting to 1.20 will limit the camera to screw-drive AF only.


Steve
04-12-2014, 10:46 AM   #14
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so, changing firmware (any version) had exactly no effect crossed off the list
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