K-x aperture problem

vicentesagredo · 08-22-2012, 07:36 AM

I've been using a K-x for about 2 1/2 years and suddenly, last week, i turned it on and it doesn't let me change the aperture.

It does changes in the viewfinder, but not in the screen and when i take the picture it uses the value that showns in the screen (wide open) and the image is overexposed (as many stops as the diference wide open-value of aperture in viewfinder)

I tried cleaning the contacts and upgrading the firmware...

hope someone knows anything about this.

Boker · 08-22-2012, 07:50 AM

Tried different lens?

Tanzer · 08-22-2012, 08:58 AM

Also, what does the EXIF data say?

vicentesagredo · 08-22-2012, 04:19 PM

tried different lenses: 18-55, 55-300, sigma 400 5.6, 10-20, f50 1.7 and same results...

exif data says wide open aperture.

thanks

Boker · 08-22-2012, 05:06 PM

Have you tried both AV and the green mode?

vicentesagredo · 08-22-2012, 06:06 PM

i've tryied all the modes, same result...

the only way to get a desired aperture is by using an aperture ring lens at manual mode.

Boker · 08-22-2012, 09:25 PM

Originally posted by Tanzer

Also, what does the EXIF data say?

This is a good suggestion to see if it reading the lens you have mounted is correct.If so you might try changing the setting allowing aperture ring.
Hope you don't have a problem with the leaver that changes aperture.

JPBigony · 08-23-2012, 09:29 AM

We just sent my son's KX for repair for the same reason. Additional problem was the camera always started up in Av mode, regardless where the control was set. If you go to the custom menu, C 22 and set it to allow manual aperture ring operation, the camera will work. The camera is not sensing the presence of an auto aperture lens, and therefore doesn't operate if C22 is set to "prohibited". We believe it to be a broken contact connection in the mounting ring on the camera.

vicentesagredo · 08-23-2012, 09:55 AM

Originally posted by JPBigony

We just sent my son's KX for repair for the same reason. Additional problem was the camera always started up in Av mode, regardless where the control was set. If you go to the custom menu, C 22 and set it to allow manual aperture ring operation, the camera will work. The camera is not sensing the presence of an auto aperture lens, and therefore doesn't operate if C22 is set to "prohibited". We believe it to be a broken contact connection in the mounting ring on the camera.

Thanks!!

I left it on "allow manual aperture ring operation" since day one, so I could always take a picture but it was at wide open aperture and overexposed at some specific conditions.

please, let me know how your experience with the repair goes.

JPBigony · 10-01-2012, 09:46 AM

Received the Kx back from Pentax repair (approximately 1 month). Repair form states "Repaired Mount Encoder Contact Circuit". The camera now works as new. I am glad I purchased an extended warranty when I bought the camera (2 additional years).

wave trust · 10-02-2012, 05:00 AM

could you please provide some more info on the repair? did they change the whole circuit block for aperture or did they managed to fix it? Or was it just a contact fault inside the mount? I believe i have the same issue with a k20d, from what i talked with the guys on the forum...
thanks.

altopiet · 10-02-2012, 05:35 AM

Originally posted by vicentesagredo

I've been using a K-x for about 2 1/2

Mine is also about that age, how many shutter actuations did your K-x have when trouble started?

wave trust · 10-02-2012, 06:14 AM

mine has around 14k... but i don't think the issues has to do with the shutter, since the camera can't control the aperture when the lens is on A mode, or am i wrong?

vicentesagredo · 10-02-2012, 06:21 AM

Originally posted by JPBigony

Received the Kx back from Pentax repair (approximately 1 month). Repair form states "Repaired Mount Encoder Contact Circuit". The camera now works as new. I am glad I purchased an extended warranty when I bought the camera (2 additional years).

Thanks, now i know it can be repaired. I'll try to find some repair center closer, the closest one seems to be at around 4.000 milles LOL

Originally posted by altopiet

Mine is also about that age, how many shutter actuations did your K-x have when trouble started?

it only has about 20.000

altopiet · 10-02-2012, 06:33 AM

"mine has around 14k... but i don't think the issues has to do with the shutter, since the camera can't control the aperture when the lens is on A mode, or am i wrong?"

You're correct, actually just asked as a matter of interest, should have asked how often the aperture have been changed using the control wheel... or something that might have an influence on the aperture. I shoot mostly in AV and usually at f7.1, and don't use the camera controls to change that very often. I have about 32000 actuations on mine. If you use a lens with an "A" setting, the camera controls the aperture, to my knowledge.

08-22-2012, 07:36 AM	#1
vicentesagredo Senior Member Join Date: Mar 2010 Location: Concepcion Posts: 100	K-x aperture problem I've been using a K-x for about 2 1/2 years and suddenly, last week, i turned it on and it doesn't let me change the aperture. It does changes in the viewfinder, but not in the screen and when i take the picture it uses the value that showns in the screen (wide open) and the image is overexposed (as many stops as the diference wide open-value of aperture in viewfinder) I tried cleaning the contacts and upgrading the firmware... hope someone knows anything about this.

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08-22-2012, 07:50 AM	#2
Boker Senior Member Join Date: Jul 2012 Location: SW Florida Posts: 234	Tried different lens?

08-22-2012, 08:58 AM	#3
Tanzer Veteran Member Join Date: Mar 2012 Location: Perrineville, NJ Posts: 1,375	Also, what does the EXIF data say?

08-22-2012, 04:19 PM	#4
vicentesagredo Senior Member Join Date: Mar 2010 Location: Concepcion Posts: 100 Original Poster	tried different lenses: 18-55, 55-300, sigma 400 5.6, 10-20, f50 1.7 and same results... exif data says wide open aperture. thanks

08-22-2012, 05:06 PM	#5
Boker Senior Member Join Date: Jul 2012 Location: SW Florida Posts: 234	Have you tried both AV and the green mode?

08-22-2012, 06:06 PM	#6
vicentesagredo Senior Member Join Date: Mar 2010 Location: Concepcion Posts: 100 Original Poster	i've tryied all the modes, same result... the only way to get a desired aperture is by using an aperture ring lens at manual mode.

08-22-2012, 09:25 PM	#7
Boker Senior Member Join Date: Jul 2012 Location: SW Florida Posts: 234	Originally posted by Tanzer Also, what does the EXIF data say? This is a good suggestion to see if it reading the lens you have mounted is correct.If so you might try changing the setting allowing aperture ring. Hope you don't have a problem with the leaver that changes aperture.

08-23-2012, 09:29 AM	#8
JPBigony New Member Join Date: Jun 2009 Location: Bowie, MD Posts: 8	We just sent my son's KX for repair for the same reason. Additional problem was the camera always started up in Av mode, regardless where the control was set. If you go to the custom menu, C 22 and set it to allow manual aperture ring operation, the camera will work. The camera is not sensing the presence of an auto aperture lens, and therefore doesn't operate if C22 is set to "prohibited". We believe it to be a broken contact connection in the mounting ring on the camera.

08-23-2012, 09:55 AM	#9
vicentesagredo Senior Member Join Date: Mar 2010 Location: Concepcion Posts: 100 Original Poster	Originally posted by JPBigony We just sent my son's KX for repair for the same reason. Additional problem was the camera always started up in Av mode, regardless where the control was set. If you go to the custom menu, C 22 and set it to allow manual aperture ring operation, the camera will work. The camera is not sensing the presence of an auto aperture lens, and therefore doesn't operate if C22 is set to "prohibited". We believe it to be a broken contact connection in the mounting ring on the camera. Thanks!! I left it on "allow manual aperture ring operation" since day one, so I could always take a picture but it was at wide open aperture and overexposed at some specific conditions. please, let me know how your experience with the repair goes.

10-01-2012, 09:46 AM	#10
JPBigony New Member Join Date: Jun 2009 Location: Bowie, MD Posts: 8	Received the Kx back from Pentax repair (approximately 1 month). Repair form states "Repaired Mount Encoder Contact Circuit". The camera now works as new. I am glad I purchased an extended warranty when I bought the camera (2 additional years).

10-02-2012, 05:00 AM	#11
wave trust Inactive Account Join Date: Sep 2012 Posts: 32	could you please provide some more info on the repair? did they change the whole circuit block for aperture or did they managed to fix it? Or was it just a contact fault inside the mount? I believe i have the same issue with a k20d, from what i talked with the guys on the forum... thanks.

10-02-2012, 05:35 AM	#12
altopiet Veteran Member Join Date: Sep 2010 Location: The Gem of the Karoo, South Africa Photos: Gallery \| Albums Posts: 2,307	Originally posted by vicentesagredo I've been using a K-x for about 2 1/2 Mine is also about that age, how many shutter actuations did your K-x have when trouble started?

10-02-2012, 06:14 AM	#13
wave trust Inactive Account Join Date: Sep 2012 Posts: 32	mine has around 14k... but i don't think the issues has to do with the shutter, since the camera can't control the aperture when the lens is on A mode, or am i wrong?

10-02-2012, 06:21 AM	#14
vicentesagredo Senior Member Join Date: Mar 2010 Location: Concepcion Posts: 100 Original Poster	Originally posted by JPBigony Received the Kx back from Pentax repair (approximately 1 month). Repair form states "Repaired Mount Encoder Contact Circuit". The camera now works as new. I am glad I purchased an extended warranty when I bought the camera (2 additional years). Thanks, now i know it can be repaired. I'll try to find some repair center closer, the closest one seems to be at around 4.000 milles LOL Originally posted by altopiet Mine is also about that age, how many shutter actuations did your K-x have when trouble started? it only has about 20.000

10-02-2012, 06:33 AM	#15
altopiet Veteran Member Join Date: Sep 2010 Location: The Gem of the Karoo, South Africa Photos: Gallery \| Albums Posts: 2,307	"mine has around 14k... but i don't think the issues has to do with the shutter, since the camera can't control the aperture when the lens is on A mode, or am i wrong?" You're correct, actually just asked as a matter of interest, should have asked how often the aperture have been changed using the control wheel... or something that might have an influence on the aperture. I shoot mostly in AV and usually at f7.1, and don't use the camera controls to change that very often. I have about 32000 actuations on mine. If you use a lens with an "A" setting, the camera controls the aperture, to my knowledge.