Is this exposure event a problem on my K70?

**psoo** · 01-29-2021, 06:03 AM

A couple of years ago I had the dreaded aperture block problem on my K50. I had it repaired in California for $100 and it worked well after that. However, I upgraded to a used K70 to try to improve my photos and safeguard against the K50 failing again. I recently encountered an event on the K70 that I had never seen before, and I want advice to see if this is the start of the aperture block problem again. I was using a DA 18-135 mm zoom at the time.

At dusk one day, I wanted to take a picture of the pond in my back yard. My K70 was set to aperture control at f/6.3. The ISO was was on auto and I was using auto white balance. I also had not changed the exposure control using the +/- button. The first shop was dark and seemed similar to the image I would have seen with my naked eye. That is, the scene was darkish as expected dusk. My second shot was bright and clear indicating that the camera compensated for the dim lighting and brought the image to full illumination, which is what I was used to. Every following shot gave normal exposures. When I checked the exposure data for the two shots they both gave the same result - f/6.3, ISO 800, exposure 1/60 sec. I checked to see if this happened on other days and in fact it happened on two other days as well. Removing and re-seating the lens, and twiddling the selection knob had no effect in fixing the problem, if it is a problem.

I want to ask if anybody has encountered this event before. Is it the beginning of the aperture block problem?

What say ye, learned Pentaxians?

The Squirrel Mafia · 01-29-2021, 07:44 AM

Probably the beginning. Sad to say that Ricoh didn't really do anything about that issue other than what seems to be a very tiny modification to the solenoid, but it still fails on some K-70 cameras.

How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com

Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - PentaxForums.com

^ Visit those 2 threads.

**gump** · 01-29-2021, 08:10 AM

I have had what may be the same thing happen a couple times. It has been the first image of the day. It may be the dreaded aperture/solenoid, however it goes to post processing and I can recover the image to a useable level. I may be whistling past the graveyard but I pretend it is just user-error of not paying attention to the focus point. I am usually starting early in the morning when the light contrasts can be extreme.

**psoo** · 01-29-2021, 09:02 AM - **1 Like**

Originally posted by gump

I have had what may be the same thing happen a couple times. It has been the first image of the day. It may be the dreaded aperture/solenoid, however it goes to post processing and I can recover the image to a useable level. I may be whistling past the graveyard but I pretend it is just user-error of not paying attention to the focus point. I am usually starting early in the morning when the light contrasts can be extreme.

Hi Gump, I don't think my problem is connected to changing the focus point. My first and second shots were for identical scenes. One thought I initially had was that the lens blades could be sticky but this would slow the blades as they stopped down and this would lead to a brighter image. However, I'll try another lens and see if the problem still occurs. I'll keep you posted on what I find.

SharkyCA · 01-29-2021, 10:24 AM

Originally posted by psoo

Hi Gump, I don't think my problem is connected to changing the focus point. My first and second shots were for identical scenes. One thought I initially had was that the lens blades could be sticky but this would slow the blades as they stopped down and this would lead to a brighter image. However, I'll try another lens and see if the problem still occurs. I'll keep you posted on what I find.

Sounds like my K-70 when it failed, check shutter count, manufactured date, is it under warranty?
Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - PentaxForums.com

**psoo** · 01-29-2021, 12:18 PM

Originally posted by SharkyCA

Sounds like my K-70 when it failed, check shutter count, manufactured date, is it under warranty?
Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - PentaxForums.com

My K70 was bought used and I've used it for a couple of years. Therefore, I'm sure it's not under warranty. As I mentioned above, I thought there was an outside chance the 18-135mm lens could have been involved so I decided to check it out. I switched the lens for my DA12-24mm lens and the same problem occurred, so it's not the lens. I may want to have it repaired since I don't trust myself to do a good job. Does anybody know what Precision or Eric charge for this repair?

stevebrot · 01-29-2021, 12:39 PM

Is it metering or exposure that is causing your problem. (Repeat with same settings in M mode, fixed ISO).) If exposure, is it the lens or the camera? (Check for sticky/hesitant blades.) If neither of the above, check the aperture control on the camera using available instructions.

Steve

**psoo** · 01-29-2021, 06:56 PM

HI Steve, I think I may be on to something. When I took my photos, the ISO was said to be on "auto" as shown on the 4-sided control on the back of the camera. However, the data on each photo was stated to be 800. So I'm not sure what the actual ISO was. Also, for the first dark shot, and the second properly exposed shot, the shutter speed was the same. That is strange because the dark shot should have had a shorter exposure time. I also tried to set the ISO to a fixed value using the thumb wheel. When I pressed OK the 4-sided controller still said the camera was on "auto". What do you think?

gatorguy · 01-29-2021, 07:01 PM - **1 Like**

Curious if you're using a Pentax-branded battery or a third-party one.

**psoo** · 01-29-2021, 08:07 PM

Originally posted by gatorguy

Curious if you're using a Pentax-branded battery or a third-party one.

Hi Gatorguy. The battery was a charged Pentax one, but I have also used non-Pentax batteries as well. I never had a problem with any battery in my K70 or K50. Even when a battery was nearly flat, the camera would operate properly. I just can't figure out why I can't set a fixed ISO. Maybe the problem is not associated with the aperture block problem.

gatorguy · 01-30-2021, 04:42 AM

Originally posted by psoo

Hi Gatorguy. The battery was a charged Pentax one, but I have also used non-Pentax batteries as well. I never had a problem with any battery in my K70 or K50. Even when a battery was nearly flat, the camera would operate properly. I just can't figure out why I can't set a fixed ISO. Maybe the problem is not associated with the aperture block problem.

I ask because using a third party Watson battery on my K1 has caused a first black frame. Afterward it will be fine for the rest of the shoot. It's repeatable and proven on my camera, and something I originally suspected might require a main board replacement if it got worse..The two genuine Pentax brand have never been an issue and prevents that first black frame.

Has it always been like that? Most assuredly not, it's something that seems to present itself with an older 3rd party battery. Something to be cognizant of even if the K1 and K70 have different aperture systems.

**gump** · 01-30-2021, 01:01 PM

Originally posted by gatorguy

I ask because using a third party Watson battery on my K1 has caused a first black frame.

I will have to test this as I have one Watson in my battery rotation. My experience is that the first frame will be dark (seriously underexposed) not black. What would cause this?

gatorguy · 01-30-2021, 01:10 PM - **1 Like**

Originally posted by gump

I will have to test this as I have one Watson in my battery rotation. My experience is that the first frame will be dark (seriously underexposed) not black. What would cause this?

Correct, I shouldn't have said "black", more seriously underexposed. There's likely a very very small difference in power delivery.

**photogem** · 01-31-2021, 01:02 AM

Originally posted by gump

I will have to test this as I have one Watson in my battery rotation. My experience is that the first frame will be dark (seriously underexposed) not black. What would cause this?

When the solenoid fails, it starts like that.
Black it never is! Just seriously underexposed up to almost black.
If you adjust brightness or similar with Adobe PS then you can see a little bit more of the original photo, but of course in terrible quality.

Originally posted by The Squirrel Mafia

Sad to say that Ricoh didn't really do anything about that issue other than what seems to be a very tiny modification to the solenoid, but it still fails on some K-70 cameras.

One can put it like this, but:

- Solenoid failures went right down under the 2% failure rate which is normal and every manufacturer has something like that.
- Of this 2% failure rate of course not all are failed solenoids but even it it would be so:

Lucky he, who owns a Pentax which fails like this!

Because if you'd own Canikon or Sofu you'd be bust, no chance for DIY repair!

**psoo** · 01-31-2021, 06:16 AM

Originally posted by photogem

When the solenoid fails, it starts like that.
Black it never is! Just seriously underexposed up to almost black.
If you adjust brightness or similar with Adobe PS then you can see a little bit more of the original photo, but of course in terrible quality.

One can put it like this, but:

- Solenoid failures went right down under the 2% failure rate which is normal and every manufacturer has something like that.
- Of this 2% failure rate of course not all are failed solenoids but even it it would be so:

Lucky he, who owns a Pentax which fails like this!

Because if you'd own Canikon or Sofu you'd be bust, no chance for DIY repair!

I'm continuing to research my problem. However I set my exposure mode ((aperture control, time control, P) I still get a darkened first image. All subsequent shots are OK. If the solenoid is acting up I suppose a low battery voltage could be involved. I use Pentax and Nixxell batteries and they have always served me well. I'll try four AA batteries to see if this could give a higher voltage than the Pentax batteries. Who knows, maybe it will work if the four AA's give a higher voltage.

01-29-2021, 06:03 AM	#1
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485	Is this exposure event a problem on my K70? A couple of years ago I had the dreaded aperture block problem on my K50. I had it repaired in California for $100 and it worked well after that. However, I upgraded to a used K70 to try to improve my photos and safeguard against the K50 failing again. I recently encountered an event on the K70 that I had never seen before, and I want advice to see if this is the start of the aperture block problem again. I was using a DA 18-135 mm zoom at the time. At dusk one day, I wanted to take a picture of the pond in my back yard. My K70 was set to aperture control at f/6.3. The ISO was was on auto and I was using auto white balance. I also had not changed the exposure control using the +/- button. The first shop was dark and seemed similar to the image I would have seen with my naked eye. That is, the scene was darkish as expected dusk. My second shot was bright and clear indicating that the camera compensated for the dim lighting and brought the image to full illumination, which is what I was used to. Every following shot gave normal exposures. When I checked the exposure data for the two shots they both gave the same result - f/6.3, ISO 800, exposure 1/60 sec. I checked to see if this happened on other days and in fact it happened on two other days as well. Removing and re-seating the lens, and twiddling the selection knob had no effect in fixing the problem, if it is a problem. I want to ask if anybody has encountered this event before. Is it the beginning of the aperture block problem? What say ye, learned Pentaxians?

01-30-2021, 04:42 AM	#11
gatorguy Moderator Join Date: Feb 2015 Location: Central Florida Photos: Gallery Posts: 6,094	Originally posted by psoo Hi Gatorguy. The battery was a charged Pentax one, but I have also used non-Pentax batteries as well. I never had a problem with any battery in my K70 or K50. Even when a battery was nearly flat, the camera would operate properly. I just can't figure out why I can't set a fixed ISO. Maybe the problem is not associated with the aperture block problem. I ask because using a third party Watson battery on my K1 has caused a first black frame. Afterward it will be fine for the rest of the shoot. It's repeatable and proven on my camera, and something I originally suspected might require a main board replacement if it got worse..The two genuine Pentax brand have never been an issue and prevents that first black frame. Has it always been like that? Most assuredly not, it's something that seems to present itself with an older 3rd party battery. Something to be cognizant of even if the K1 and K70 have different aperture systems. Last edited by gatorguy; 01-30-2021 at 06:12 AM.

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01-29-2021, 07:44 AM	#2
The Squirrel Mafia Pentaxian Join Date: Jan 2015 Posts: 3,058	Probably the beginning. Sad to say that Ricoh didn't really do anything about that issue other than what seems to be a very tiny modification to the solenoid, but it still fails on some K-70 cameras. How to detect aperture-block failure/stuck solenoid on Pentax K-70 - PentaxForums.com Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - PentaxForums.com ^ Visit those 2 threads.

01-29-2021, 08:10 AM	#3
gump Site Supporter Join Date: Apr 2018 Location: Canton, Ohio Posts: 1,016	I have had what may be the same thing happen a couple times. It has been the first image of the day. It may be the dreaded aperture/solenoid, however it goes to post processing and I can recover the image to a useable level. I may be whistling past the graveyard but I pretend it is just user-error of not paying attention to the focus point. I am usually starting early in the morning when the light contrasts can be extreme.

01-29-2021, 09:02 AM - 1 Like	#4
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485 Original Poster	Originally posted by gump I have had what may be the same thing happen a couple times. It has been the first image of the day. It may be the dreaded aperture/solenoid, however it goes to post processing and I can recover the image to a useable level. I may be whistling past the graveyard but I pretend it is just user-error of not paying attention to the focus point. I am usually starting early in the morning when the light contrasts can be extreme. Hi Gump, I don't think my problem is connected to changing the focus point. My first and second shots were for identical scenes. One thought I initially had was that the lens blades could be sticky but this would slow the blades as they stopped down and this would lead to a brighter image. However, I'll try another lens and see if the problem still occurs. I'll keep you posted on what I find.

01-29-2021, 10:24 AM	#5
SharkyCA Pentaxian Join Date: Sep 2017 Location: Carleton Place, Ontario, Canada Photos: Gallery Posts: 806	Originally posted by psoo Hi Gump, I don't think my problem is connected to changing the focus point. My first and second shots were for identical scenes. One thought I initially had was that the lens blades could be sticky but this would slow the blades as they stopped down and this would lead to a brighter image. However, I'll try another lens and see if the problem still occurs. I'll keep you posted on what I find. Sounds like my K-70 when it failed, check shutter count, manufactured date, is it under warranty? Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - PentaxForums.com

01-29-2021, 12:18 PM	#6
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485 Original Poster	Originally posted by SharkyCA Sounds like my K-70 when it failed, check shutter count, manufactured date, is it under warranty? Tutorial/Repair Pentax K-70 with aperture-problem: Exchange solenoid - PentaxForums.com My K70 was bought used and I've used it for a couple of years. Therefore, I'm sure it's not under warranty. As I mentioned above, I thought there was an outside chance the 18-135mm lens could have been involved so I decided to check it out. I switched the lens for my DA12-24mm lens and the same problem occurred, so it's not the lens. I may want to have it repaired since I don't trust myself to do a good job. Does anybody know what Precision or Eric charge for this repair?

01-29-2021, 12:39 PM	#7
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Is it metering or exposure that is causing your problem. (Repeat with same settings in M mode, fixed ISO).) If exposure, is it the lens or the camera? (Check for sticky/hesitant blades.) If neither of the above, check the aperture control on the camera using available instructions. Steve

01-29-2021, 06:56 PM	#8
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485 Original Poster	HI Steve, I think I may be on to something. When I took my photos, the ISO was said to be on "auto" as shown on the 4-sided control on the back of the camera. However, the data on each photo was stated to be 800. So I'm not sure what the actual ISO was. Also, for the first dark shot, and the second properly exposed shot, the shutter speed was the same. That is strange because the dark shot should have had a shorter exposure time. I also tried to set the ISO to a fixed value using the thumb wheel. When I pressed OK the 4-sided controller still said the camera was on "auto". What do you think?

01-29-2021, 07:01 PM - 1 Like	#9
gatorguy Moderator Join Date: Feb 2015 Location: Central Florida Photos: Gallery Posts: 6,094	Curious if you're using a Pentax-branded battery or a third-party one.

01-29-2021, 08:07 PM	#10
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485 Original Poster	Originally posted by gatorguy Curious if you're using a Pentax-branded battery or a third-party one. Hi Gatorguy. The battery was a charged Pentax one, but I have also used non-Pentax batteries as well. I never had a problem with any battery in my K70 or K50. Even when a battery was nearly flat, the camera would operate properly. I just can't figure out why I can't set a fixed ISO. Maybe the problem is not associated with the aperture block problem.

01-30-2021, 01:01 PM	#12
gump Site Supporter Join Date: Apr 2018 Location: Canton, Ohio Posts: 1,016	Originally posted by gatorguy I ask because using a third party Watson battery on my K1 has caused a first black frame. I will have to test this as I have one Watson in my battery rotation. My experience is that the first frame will be dark (seriously underexposed) not black. What would cause this?

01-30-2021, 01:10 PM - 1 Like	#13
gatorguy Moderator Join Date: Feb 2015 Location: Central Florida Photos: Gallery Posts: 6,094	Originally posted by gump I will have to test this as I have one Watson in my battery rotation. My experience is that the first frame will be dark (seriously underexposed) not black. What would cause this? Correct, I shouldn't have said "black", more seriously underexposed. There's likely a very very small difference in power delivery.

01-31-2021, 01:02 AM	#14
photogem Site Supporter Join Date: Apr 2015 Posts: 3,525	Originally posted by gump I will have to test this as I have one Watson in my battery rotation. My experience is that the first frame will be dark (seriously underexposed) not black. What would cause this? When the solenoid fails, it starts like that. Black it never is! Just seriously underexposed up to almost black. If you adjust brightness or similar with Adobe PS then you can see a little bit more of the original photo, but of course in terrible quality. Originally posted by The Squirrel Mafia Sad to say that Ricoh didn't really do anything about that issue other than what seems to be a very tiny modification to the solenoid, but it still fails on some K-70 cameras. One can put it like this, but: - Solenoid failures went right down under the 2% failure rate which is normal and every manufacturer has something like that. - Of this 2% failure rate of course not all are failed solenoids but even it it would be so: Lucky he, who owns a Pentax which fails like this! Because if you'd own Canikon or Sofu you'd be bust, no chance for DIY repair!

01-31-2021, 06:16 AM	#15
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485 Original Poster	Originally posted by photogem When the solenoid fails, it starts like that. Black it never is! Just seriously underexposed up to almost black. If you adjust brightness or similar with Adobe PS then you can see a little bit more of the original photo, but of course in terrible quality. One can put it like this, but: - Solenoid failures went right down under the 2% failure rate which is normal and every manufacturer has something like that. - Of this 2% failure rate of course not all are failed solenoids but even it it would be so: Lucky he, who owns a Pentax which fails like this! Because if you'd own Canikon or Sofu you'd be bust, no chance for DIY repair! I'm continuing to research my problem. However I set my exposure mode ((aperture control, time control, P) I still get a darkened first image. All subsequent shots are OK. If the solenoid is acting up I suppose a low battery voltage could be involved. I use Pentax and Nixxell batteries and they have always served me well. I'll try four AA batteries to see if this could give a higher voltage than the Pentax batteries. Who knows, maybe it will work if the four AA's give a higher voltage.