K-X exposure time issue

steurm · 04-19-2015, 02:42 AM

Hi All,

Since a couple of weeks, I'm experiencing issues with my Pentax K-x, It's 5 years old, Took approx 3K pictures with it. I'll try to describe the issue:

When trying to take a picture from a bright subject, whether it be a person, nature, ..., the camera proposes to use an exposure time as expected, but when taking the picture the exposure takes 3-4 seconds and in the end no picture is taken.
In darker environments the camera seems to react normal.
The same behaviour applies to manual or automatic settings, no sunny pictures to be taken at the moment

In the meantime I've tried to reset to factory defaults, applied firmware v1.03, to no avail.

Maybe someone of you could help me finding out the cause of this issue ?

Thanks upfront !

Bill2849 · 04-19-2015, 10:32 AM

I am a K-x user of nearly 5 years myself. I do not think that I've ever had this issue myself.

I do know some things I might check out if I did have this problem. You may well have tried these, but I will post them here in the hope that perhaps one or more of these questions will either help you directly or else help someone more knowledgeable better understand your problem. I apologize in advance if these seem too basic. If it does, this is a reflection of my limited understanding and experience and does not reflect any presumption regarding your own knowledge and skills.

Does this occur when the camera and lens are in manual focus mode?

Does this occur with more than one lens? If this is occurring with an older lens, have you made sure that the aperture ring is set to A and/or that your C Custom Setting for permitting the use of the Aperture Ring (C Custom Setting 4, 22) is set to "permitted"?

If you switch the camera to shutter priority mode can you determine either the slowest shutter speed that will take a picture or the fastest shutter speed that will not take a picture?

When you say the camera will not take a photo in bright situations, do you mean that there is no file created on your SD card (as opposed to creating a blank white image or a blank black image)?

Have you checked your ISO and/or exposure compensation (EV) settings to make sure that these are not contributing to the problem?

Best wishes,

steurm · 04-21-2015, 12:53 AM

Hi,

Thanks for your reply. Like you say : any suggestion might help.

Does this occur when the camera and lens are in manual focus mode? answer --> yes, not difference on this level

Does this occur with more than one lens? If this is occurring with an older lens, have you made sure that the aperture ring is set to A and/or that your C Custom Setting for permitting the use of the Aperture Ring (C Custom Setting 4, 22) is set to "permitted"? answer --> yes, I have the standard 18-55 lens and an older 80-320mm pentax lens, which I only used in the A setting. The issue arises with both lenses

If you switch the camera to shutter priority mode can you determine either the slowest shutter speed that will take a picture or the fastest shutter speed that will not take a picture? answer --> didn't do that yet, will try that out to see if I can find such a shutter speed.

When you say the camera will not take a photo in bright situations, do you mean that there is no file created on your SD card (as opposed to creating a blank white image or a blank black image)? answer --> indeed, no picture is to be found on the SD card.

Have you checked your ISO and/or exposure compensation (EV) settings to make sure that these are not contributing to the problem? answer --> I've tried different EV settings, auto ISO settings, as well as manual ISO settings, to no avail.

Anyone else with more suggestions ?
Thanks!

steurm · 04-23-2015, 05:52 AM

Hi again,

In the meantime I'v tried to set the 'slowest' shutter speed which works. It's around 1/1600. However, it results in under exposured pictures. Could this mean that a light sensor is faulty ?

Bill2849 · 04-24-2015, 08:49 AM

Originally posted by steurm

Hi again,

In the meantime I'v tried to set the 'slowest' shutter speed which works. It's around 1/1600. However, it results in under exposured pictures. Could this mean that a light sensor is faulty ?

I'm not quite sure what you mean (I know that this was originally my suggestion and I was not specific), when you speak of the "'slowest' shutter speed that works." In your original post you reported being able to take pictures in dark settings but not in bright settings. That suggests to me that you are able to take photos at slower shutter speeds but not at faster shutter speeds and that 1/1600 would seem to be more likely the fastest shutter speed that works, but that you get under exposed pictures at that speed.

I assume you were trying this in shutter priority mode so that the camera's only options for adjusting exposure (if it needs adjusting) is to change the lens aperture and/or the ISO setting. The lens aperture cannot open wider than it's widest setting (which on the 18-55mm kit lens will be between 3.5 - at 18mm - to 5.6 - at 55mm) and the ISO setting can only be changed by the camera if you have auto-ISO enabled, and then it will only vary between the ISO range you specify. So it is possible that this under-exposed photo was under exposed at 1/1600 was under exposed because the camera had reached its widest aperture setting and highest specified ISO. In that case you could always try a higher ISO setting. However, you should have gotten an exposure warning in the form of a blinking light on the EV display on both the view finder and status screen. This can be overlooked (I've done so several times myself).

I do not think the light sensor is at fault because you report that the camera will take photos in dark settings but not in bright settings, and also it appears to determine a correct exposure in bright settings but then the camera refuses to take the photo (but it will in dark settings). This suggests to me that the sensor itself seems unlikely to be at fault. However, if you are certain that you do NOT get an exposure warning in a situation such as the one you suggest in your example of the 1/1600 photo, then that might lead me to reconsider the sensor as being at fault.

If the shutter were somehow at fault (since it is refusing to take the photo), it does not make sense that the shutter will work in some situations and not in others.

It could be that your problems might be related to some obscure settings somewhere (such as having to do with white balance, custom image settings, dynamic range) or to some electronic or mechanical problem (since you have already re-installed the firmware, we will assume that the firmware is not at issue here). However, I am at a loss as how to best proceed.

Perhaps someone else has better insight into this.

I'll continue to think about this but I am not optimistic. If you do have more information to add, please feel free to post it.

Best wishes,

04-19-2015, 02:42 AM	#1
steurm New Member Join Date: Apr 2015 Posts: 3	K-X exposure time issue Hi All, Since a couple of weeks, I'm experiencing issues with my Pentax K-x, It's 5 years old, Took approx 3K pictures with it. I'll try to describe the issue: When trying to take a picture from a bright subject, whether it be a person, nature, ..., the camera proposes to use an exposure time as expected, but when taking the picture the exposure takes 3-4 seconds and in the end no picture is taken. In darker environments the camera seems to react normal. The same behaviour applies to manual or automatic settings, no sunny pictures to be taken at the moment In the meantime I've tried to reset to factory defaults, applied firmware v1.03, to no avail. Maybe someone of you could help me finding out the cause of this issue ? Thanks upfront !

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04-19-2015, 10:32 AM	#2
Bill2849 Veteran Member Join Date: Dec 2011 Photos: Albums Posts: 579	I am a K-x user of nearly 5 years myself. I do not think that I've ever had this issue myself. I do know some things I might check out if I did have this problem. You may well have tried these, but I will post them here in the hope that perhaps one or more of these questions will either help you directly or else help someone more knowledgeable better understand your problem. I apologize in advance if these seem too basic. If it does, this is a reflection of my limited understanding and experience and does not reflect any presumption regarding your own knowledge and skills. Does this occur when the camera and lens are in manual focus mode? Does this occur with more than one lens? If this is occurring with an older lens, have you made sure that the aperture ring is set to A and/or that your C Custom Setting for permitting the use of the Aperture Ring (C Custom Setting 4, 22) is set to "permitted"? If you switch the camera to shutter priority mode can you determine either the slowest shutter speed that will take a picture or the fastest shutter speed that will not take a picture? When you say the camera will not take a photo in bright situations, do you mean that there is no file created on your SD card (as opposed to creating a blank white image or a blank black image)? Have you checked your ISO and/or exposure compensation (EV) settings to make sure that these are not contributing to the problem? Best wishes,

04-21-2015, 12:53 AM	#3
steurm New Member Join Date: Apr 2015 Posts: 3 Original Poster	Hi, Thanks for your reply. Like you say : any suggestion might help. Does this occur when the camera and lens are in manual focus mode? answer --> yes, not difference on this level Does this occur with more than one lens? If this is occurring with an older lens, have you made sure that the aperture ring is set to A and/or that your C Custom Setting for permitting the use of the Aperture Ring (C Custom Setting 4, 22) is set to "permitted"? answer --> yes, I have the standard 18-55 lens and an older 80-320mm pentax lens, which I only used in the A setting. The issue arises with both lenses If you switch the camera to shutter priority mode can you determine either the slowest shutter speed that will take a picture or the fastest shutter speed that will not take a picture? answer --> didn't do that yet, will try that out to see if I can find such a shutter speed. When you say the camera will not take a photo in bright situations, do you mean that there is no file created on your SD card (as opposed to creating a blank white image or a blank black image)? answer --> indeed, no picture is to be found on the SD card. Have you checked your ISO and/or exposure compensation (EV) settings to make sure that these are not contributing to the problem? answer --> I've tried different EV settings, auto ISO settings, as well as manual ISO settings, to no avail. Anyone else with more suggestions ? Thanks!

04-23-2015, 05:52 AM	#4
steurm New Member Join Date: Apr 2015 Posts: 3 Original Poster	Hi again, In the meantime I'v tried to set the 'slowest' shutter speed which works. It's around 1/1600. However, it results in under exposured pictures. Could this mean that a light sensor is faulty ?

04-24-2015, 08:49 AM	#5
Bill2849 Veteran Member Join Date: Dec 2011 Photos: Albums Posts: 579	Originally posted by steurm Hi again, In the meantime I'v tried to set the 'slowest' shutter speed which works. It's around 1/1600. However, it results in under exposured pictures. Could this mean that a light sensor is faulty ? I'm not quite sure what you mean (I know that this was originally my suggestion and I was not specific), when you speak of the "'slowest' shutter speed that works." In your original post you reported being able to take pictures in dark settings but not in bright settings. That suggests to me that you are able to take photos at slower shutter speeds but not at faster shutter speeds and that 1/1600 would seem to be more likely the fastest shutter speed that works, but that you get under exposed pictures at that speed. I assume you were trying this in shutter priority mode so that the camera's only options for adjusting exposure (if it needs adjusting) is to change the lens aperture and/or the ISO setting. The lens aperture cannot open wider than it's widest setting (which on the 18-55mm kit lens will be between 3.5 - at 18mm - to 5.6 - at 55mm) and the ISO setting can only be changed by the camera if you have auto-ISO enabled, and then it will only vary between the ISO range you specify. So it is possible that this under-exposed photo was under exposed at 1/1600 was under exposed because the camera had reached its widest aperture setting and highest specified ISO. In that case you could always try a higher ISO setting. However, you should have gotten an exposure warning in the form of a blinking light on the EV display on both the view finder and status screen. This can be overlooked (I've done so several times myself). I do not think the light sensor is at fault because you report that the camera will take photos in dark settings but not in bright settings, and also it appears to determine a correct exposure in bright settings but then the camera refuses to take the photo (but it will in dark settings). This suggests to me that the sensor itself seems unlikely to be at fault. However, if you are certain that you do NOT get an exposure warning in a situation such as the one you suggest in your example of the 1/1600 photo, then that might lead me to reconsider the sensor as being at fault. If the shutter were somehow at fault (since it is refusing to take the photo), it does not make sense that the shutter will work in some situations and not in others. It could be that your problems might be related to some obscure settings somewhere (such as having to do with white balance, custom image settings, dynamic range) or to some electronic or mechanical problem (since you have already re-installed the firmware, we will assume that the firmware is not at issue here). However, I am at a loss as how to best proceed. Perhaps someone else has better insight into this. I'll continue to think about this but I am not optimistic. If you do have more information to add, please feel free to post it. Best wishes,