Pentax kx ISO problem

l.b9 · 02-19-2014, 06:31 AM

Hi all,

I've been searching around for a solution or reason to this problem but have not been exactly successful in my search.

This happened a while ago on a trip overseas. I was in movie mode at the airport and thought I had turned the camera off before boarding the plan. After a two hours flight and retrieving my camera bag from the overhead compartment I noticed it was extremely hot. I checked and the camera was still on, live view still playing and the screen almost burning. I quickly turned it off and allowed it to cool till the next day.

I hadn't noticed any problem right away with the camera when using it after. However every now and then it seems when operating in Auto mode, it would fail to select a higher ISO in low lighting condition. I have even tried to manually change the ISO and photos taken at ISO 200 seems exactly the same as those taken at 3200. I don't seem to notice a difference in noise either and even though the data shows it was taken at 3200 or 6400, the image is still dark as if taken at 200. Only way around it for me is to play with the aperture and shutter speed some times.

The odd thing is this only occurs every now and then. And more often when using the kit 18-55 mm. I use a 50 mm f 1.4 mainly.

Hoping to shed some light o this problem? Have I "burnt" something when it over heated?

It's been a fantastic camera otherwise.

Sorry for the long post and thanks in advance for your assistance.

Na Horuk · 02-19-2014, 06:36 AM

Hey there. Can you verify if the problem is the lens/aperture blades being sticky?
Beyond that, its not impossible that the heat would damage the camera, but I think it would turn of if it came to that?

lytrytyr · 02-19-2014, 07:06 AM

Originally posted by Na Horuk

Can you verify if the problem is the lens/aperture blades being sticky?

Wouldn't sticky blades lead to over-exposed images, not ones that are "still dark"?

---------- Post added 02-19-14 at 08:13 AM ----------

Originally posted by l.b9

After a two hours flight and retrieving my camera bag from the overhead compartment I noticed it was extremely hot. I checked and the camera was still on, live view still playing and the screen almost burning.

The camera should have turned itself off after a set period of inactivity.

The only scenario I can imagine here
is that the vibration of the plane
and the tight packing of the baggage in the compartment
meant that the shutter button kept getting jiggled during the flight.

Otherwise, you may have some kind of obscure problem with the camera's processor
(not unusual in a K-x that is now several years old).

If you no longer have confidence in the camera,
I would suggest replacing it with a new K-500 (or K-50 if you find one on sale).

l.b9 · 02-19-2014, 07:15 AM

I'm not sure. To be honest I haven't noticed the problem at all when using the 50 mm though I shoot often at less than f 3.5 so it may help with the low lighting conditions.

It's just odd that no matter what iso setting I chose the image looks the same. If in Auto it seems to want to select iso 200 and will only go up to 400 when I partially cover the lens.

I thought there was a safety feature that turned the camera off when it got too hot. But it seemed that it didn't kick in while in movie mode.

---------- Post added 02-19-14 at 07:28 AM ----------

Thanks lytrytyr.

I just thought it was odd. Also only happens intermittently.

Enjoying the kx still for its size but am looking at possibly moving to a k5.

NicoleC · 02-19-2014, 08:08 AM

Your post is making me wish I saved some of the bad images when my Kx went on the fritz. I also had very dark or black frames and I didn't think to check the ISO. Yes, just every now and then, and the specific lens didn't make a difference. My camera was never overheated, though.

I upgraded and am very happy, but it would be nice if I had a back up body I felt confident in!

Na Horuk · 02-19-2014, 08:57 AM

Can you try using another battery? Or at least charge it and leave it outside overnight.
The standard things you can do is reset to factory defaults, update the firmware, check to see if there is anything on contacts (battery, SD, lens). Doubt any of these things are the culprit, but it might be worth the try.

hartless_1 · 02-20-2014, 05:31 AM

Originally posted by Na Horuk

The standard things you can do is reset to factory defaults, update the firmware, check to see if there is anything on contacts (battery, SD, lens). Doubt any of these things are the culprit, but it might be worth the try.

Agree completely. Have had to clean contacts a few times myself.
Also, you can still `update` the firmware even if it`s already on 1.03. Just reset (2 places in menu) before and after `updating`. Have done that a few times too.
g/l

02-19-2014, 06:31 AM	#1
l.b9 New Member Join Date: Jan 2014 Posts: 5	Pentax kx ISO problem Hi all, I've been searching around for a solution or reason to this problem but have not been exactly successful in my search. This happened a while ago on a trip overseas. I was in movie mode at the airport and thought I had turned the camera off before boarding the plan. After a two hours flight and retrieving my camera bag from the overhead compartment I noticed it was extremely hot. I checked and the camera was still on, live view still playing and the screen almost burning. I quickly turned it off and allowed it to cool till the next day. I hadn't noticed any problem right away with the camera when using it after. However every now and then it seems when operating in Auto mode, it would fail to select a higher ISO in low lighting condition. I have even tried to manually change the ISO and photos taken at ISO 200 seems exactly the same as those taken at 3200. I don't seem to notice a difference in noise either and even though the data shows it was taken at 3200 or 6400, the image is still dark as if taken at 200. Only way around it for me is to play with the aperture and shutter speed some times. The odd thing is this only occurs every now and then. And more often when using the kit 18-55 mm. I use a 50 mm f 1.4 mainly. Hoping to shed some light o this problem? Have I "burnt" something when it over heated? It's been a fantastic camera otherwise. Sorry for the long post and thanks in advance for your assistance.

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02-19-2014, 06:36 AM	#2
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Hey there. Can you verify if the problem is the lens/aperture blades being sticky? Beyond that, its not impossible that the heat would damage the camera, but I think it would turn of if it came to that?

02-19-2014, 07:06 AM	#3
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Na Horuk Can you verify if the problem is the lens/aperture blades being sticky? Wouldn't sticky blades lead to over-exposed images, not ones that are "still dark"? ---------- Post added 02-19-14 at 08:13 AM ---------- Originally posted by l.b9 After a two hours flight and retrieving my camera bag from the overhead compartment I noticed it was extremely hot. I checked and the camera was still on, live view still playing and the screen almost burning. The camera should have turned itself off after a set period of inactivity. The only scenario I can imagine here is that the vibration of the plane and the tight packing of the baggage in the compartment meant that the shutter button kept getting jiggled during the flight. Otherwise, you may have some kind of obscure problem with the camera's processor (not unusual in a K-x that is now several years old). If you no longer have confidence in the camera, I would suggest replacing it with a new K-500 (or K-50 if you find one on sale).

02-19-2014, 07:15 AM	#4
l.b9 New Member Join Date: Jan 2014 Posts: 5 Original Poster	I'm not sure. To be honest I haven't noticed the problem at all when using the 50 mm though I shoot often at less than f 3.5 so it may help with the low lighting conditions. It's just odd that no matter what iso setting I chose the image looks the same. If in Auto it seems to want to select iso 200 and will only go up to 400 when I partially cover the lens. I thought there was a safety feature that turned the camera off when it got too hot. But it seemed that it didn't kick in while in movie mode. ---------- Post added 02-19-14 at 07:28 AM ---------- Thanks lytrytyr. I just thought it was odd. Also only happens intermittently. Enjoying the kx still for its size but am looking at possibly moving to a k5.

02-19-2014, 08:08 AM	#5
NicoleC Veteran Member Join Date: Oct 2013 Location: Madison, AL Posts: 448	Your post is making me wish I saved some of the bad images when my Kx went on the fritz. I also had very dark or black frames and I didn't think to check the ISO. Yes, just every now and then, and the specific lens didn't make a difference. My camera was never overheated, though. I upgraded and am very happy, but it would be nice if I had a back up body I felt confident in!

02-19-2014, 08:57 AM	#6
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Can you try using another battery? Or at least charge it and leave it outside overnight. The standard things you can do is reset to factory defaults, update the firmware, check to see if there is anything on contacts (battery, SD, lens). Doubt any of these things are the culprit, but it might be worth the try.

02-20-2014, 05:31 AM	#7
hartless_1 New Member Join Date: Sep 2010 Location: Brisbane Posts: 24	Originally posted by Na Horuk The standard things you can do is reset to factory defaults, update the firmware, check to see if there is anything on contacts (battery, SD, lens). Doubt any of these things are the culprit, but it might be worth the try. Agree completely. Have had to clean contacts a few times myself. Also, you can still `update` the firmware even if it`s already on 1.03. Just reset (2 places in menu) before and after `updating`. Have done that a few times too. g/l