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03-15-2014, 07:26 PM   #1
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K30 Underexposure

Has anyone noticed their K30 underexposing? i realize that the tendency for Pentax cameras is to underexpose but the K30 seems to do it even more.

My K30 underexposes 1 stop under all conditions. Thinking it may be the lens I tested it with the Tamron 90mm Macro and 2 pentax primes the 35mm and 50mm. It wasn't the lens

I tested it this AM taking photo's inside and out.
I took a shot when the camera meter read proper exposure. Then took a second shot using the exposure read with the sekonic L-308S meter, which showed 1 stop over exposed in the camera's meter.

The sekonic shot was exposed properly every time while the camera was under exposed every time even in sunlight.

At least the camera is consistent.

03-15-2014, 08:07 PM   #2
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QuoteOriginally posted by geru2000 Quote
At least the camera is consistent.
Ha! You hit the nail on the head for me. I've changed every menu option under the sun, and I still get underexposed shots. I'm leery of leaving the EV compensation to +1 on the off-chance that the camera actually does over-expose the one shot I need, so I mostly just deal with it in post-processing. The camera's own histogram shows that it's underexposed, but I guess it's better than the alternative...still, I miss the spot-on exposure of my K200D.
03-15-2014, 08:10 PM   #3
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Isn't the camera's histogram for the display JPEG?
03-15-2014, 09:24 PM   #4
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QuoteOriginally posted by geru2000 Quote

I tested it this AM taking photo's inside and out.
I took a shot when the camera meter read proper exposure. Then took a second shot using the exposure read with the sekonic L-308S meter, which showed 1 stop over exposed in the camera's meter.

The sekonic shot was exposed properly every time while the camera was under exposed every time even in sunlight.

At least the camera is consistent.
Can you compare readings using a gray card for both camera (center-weighted pattern) and L-308S? If you don't have a gray card, an evenly lit expanse of green grass (sun behind you) will do. That will help differentiate whether you have a meter bias (fixable) vs. matrix failure (probably not fixable).


Steve

03-16-2014, 04:11 AM   #5
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QuoteOriginally posted by geru2000 Quote
Has anyone noticed their K30 underexposing? i realize that the tendency for Pentax cameras is to underexpose but the K30 seems to do it even more.

My K30 underexposes 1 stop under all conditions. Thinking it may be the lens I tested it with the Tamron 90mm Macro and 2 pentax primes the 35mm and 50mm. It wasn't the lens

I tested it this AM taking photo's inside and out.
I took a shot when the camera meter read proper exposure. Then took a second shot using the exposure read with the sekonic L-308S meter, which showed 1 stop over exposed in the camera's meter.

The sekonic shot was exposed properly every time while the camera was under exposed every time even in sunlight.

At least the camera is consistent.
Are you capturing in RAW+ with highlight protection on? Some if not most image editors will not recognize the tag so as to boost the RAW exposure by 1 EV. With highlight protection, you really are underexposing by 1 EV. It's just that the camera corrects the JPEG for you while some application (not all) will correct the RAW, too.
03-16-2014, 06:25 AM   #6
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QuoteOriginally posted by IchabodCrane Quote
Are you capturing in RAW+ with highlight protection on? Some if not most image editors will not recognize the tag so as to boost the RAW exposure by 1 EV. With highlight protection, you really are underexposing by 1 EV. It's just that the camera corrects the JPEG for you while some application (not all) will correct the RAW, too.
Check the Menu, Camera icon <settings> 2. Try turning off both highlight and shadow correction.

I use the full AE matrix and tend to agree that my exposure is often about 1 EV low when I load the RAW image into Adobe Camera RAW (PSE12). I just deal with it, but I suspect exposure would be more accurate if I used either center weighted or spot AE. That is, if you also pay close visual attention to the metering point and tip the exposure up or down based on your estimate of how far off neutral gray the scene is at that point. So, where do you want to spend the time, at the viewfinder or at the computer?
03-16-2014, 10:07 AM   #7
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QuoteOriginally posted by K McCall Quote
Ha! You hit the nail on the head for me. I've changed every menu option under the sun, and I still get underexposed shots. I'm leery of leaving the EV compensation to +1 on the off-chance that the camera actually does over-expose the one shot I need, so I mostly just deal with it in post-processing. The camera's own histogram shows that it's underexposed, but I guess it's better than the alternative...still, I miss the spot-on exposure of my K200D.
SInce the camera seems to under expose leaving EV at +1 shouldn't bother it, at least it doesn't on my camera.

QuoteOriginally posted by EssJayEff Quote
Isn't the camera's histogram for the display JPEG?
Yes, but the JPEG is created from the RAW data in other words my RAW files are under exposed by one stop also.

QuoteOriginally posted by stevebrot Quote
Can you compare readings using a gray card for both camera (center-weighted pattern) and L-308S? If you don't have a gray card, an evenly lit expanse of green grass (sun behind you) will do. That will help differentiate whether you have a meter bias (fixable) vs. matrix failure (probably not fixable).

Steve
Definitely a meter bias. I've tried all 3 metering options and they all produce the same results 2/3rds to one stop under exposed.

QuoteOriginally posted by IchabodCrane Quote
Are you capturing in RAW+ with highlight protection on? Some if not most image editors will not recognize the tag so as to boost the RAW exposure by 1 EV. With highlight protection, you really are underexposing by 1 EV. It's just that the camera corrects the JPEG for you while some application (not all) will correct the RAW, too.
Don't use highlight protection, never have. The exposure difference is clearly visible in the image whether RAW or JPEG not to mention I get a one stop difference with the Sekonic meter. I seldom shoot in JPEG, sometimes in RAW+, but mostly just plain ole' RAW.

QuoteOriginally posted by JimJohnson Quote
Check the Menu, Camera icon <settings> 2. Try turning off both highlight and shadow correction.

I use the full AE matrix and tend to agree that my exposure is often about 1 EV low when I load the RAW image into Adobe Camera RAW (PSE12). I just deal with it, but I suspect exposure would be more accurate if I used either center weighted or spot AE. That is, if you also pay close visual attention to the metering point and tip the exposure up or down based on your estimate of how far off neutral gray the scene is at that point. So, where do you want to spend the time, at the viewfinder or at the computer?
Changing the metering option does nothing to affect my underexposure each one of them is one stop underexposed.
The underexposure isn't a complaint, it's so consistent that I plan for it. Under exposure could be taken care of in editing programs but if I can get it right in camera it's one less task I have to do in editing.

I was just curious to see if others had the same experience. Like I said in my original post I've shot Pentax since the K100 and even that camera underexposed, I found the same with the K200, and Kr but the K30 seems to underexpose more.

The underexposure was one reason why I bought a light meter. The main reason I bought it was to be able to balance ambient light and naked flash (no modifiers) to remove or soften shadows without that noticeable flash harshness.
03-16-2014, 10:45 AM   #8
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QuoteOriginally posted by geru2000 Quote
SInce the camera seems to under expose leaving EV at +1 shouldn't bother it, at least it doesn't on my camera.



Yes, but the JPEG is created from the RAW data in other words my RAW files are under exposed by one stop also.



Definitely a meter bias. I've tried all 3 metering options and they all produce the same results 2/3rds to one stop under exposed.



Don't use highlight protection, never have. The exposure difference is clearly visible in the image whether RAW or JPEG not to mention I get a one stop difference with the Sekonic meter. I seldom shoot in JPEG, sometimes in RAW+, but mostly just plain ole' RAW.



Changing the metering option does nothing to affect my underexposure each one of them is one stop underexposed.
The underexposure isn't a complaint, it's so consistent that I plan for it. Under exposure could be taken care of in editing programs but if I can get it right in camera it's one less task I have to do in editing.

I was just curious to see if others had the same experience. Like I said in my original post I've shot Pentax since the K100 and even that camera underexposed, I found the same with the K200, and Kr but the K30 seems to underexpose more.

The underexposure was one reason why I bought a light meter. The main reason I bought it was to be able to balance ambient light and naked flash (no modifiers) to remove or soften shadows without that noticeable flash harshness.
It's possible the issue is strictly a fault in your camera. I've never had a consistent underexposure problem with my K-30.

03-16-2014, 04:21 PM   #9
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QuoteOriginally posted by IchabodCrane Quote
It's possible the issue is strictly a fault in your camera. I've never had a consistent underexposure problem with my K-30.
Entirely possible.... my experience with Pentax DSLR's has been they tended to underexpose usually about a 1/3rd of a stop, but my K30 has consistently underexposed 1 stop since I've had it (about 13 months now).

I initially didn't notice it probably because I was shooting JPEG and when I removed them from the card they were immediately run through a script in Corel PaintShop Pro which corrected exposure, color, and resized among other things. It was when my Raw Development Program (another Corel program) was updated to Support the K30 that I noticed the raw files were underexposed.

Like I say it isn't a big deal and it's very easily corrected in camera. I was just interested in seeing if underexposing was prevalent in the K30 or if it was just my camera. It seems that it is a fault with my camera.
03-16-2014, 04:37 PM   #10
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QuoteOriginally posted by geru2000 Quote
Definitely a meter bias. I've tried all 3 metering options and they all produce the same results 2/3rds to one stop under exposed.
Against a uniform, non-complex target?


Steve
03-17-2014, 07:49 AM   #11
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QuoteOriginally posted by stevebrot Quote
Against a uniform, non-complex target?


Steve
Yes

(can't post just a yes says message is to short.)
05-15-2014, 02:14 PM   #12
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After using my camera for a year with no problems it suddenly started underexposing images. I now have to take 3 identical images one after the other quickly, the 1st one is usually vastly underexposed and the other 2 are ok, however the exposure information on all 3 images is identical. I've had to put up with it several months now and it's irritating as I miss capturing a good shot sometimes if it is of something moving. I have also had endless issues with dust on the sensor and have to constantly clean it, even when I've not changed lenses, in fact most of the time I'm now to worried to change them. The dust issue has been a major problem for me after only a few weeks of owning the camera. I've always loved Pentax but feel really disillusioned. I'm good with a camera and fully understand how to use it but am in no way technicalso it's really frustrating reading through reams of suggestions and info on the camera as I never have the mindset to understand the 'boring' stuff lol. All I want to do is take pics without glitches!
05-16-2014, 02:45 AM   #13
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With the lens off (in a dust free environment -you'll be lucky) take a shot and try to see if the internal aperture lever moves over the whole travel. On mine I guess it stops about 1mm short of the end stop.
05-16-2014, 03:53 AM   #14
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https://www.pentaxforums.com/forums/120-general-technical-troubleshooting/229...problem-3.html
I've been waiting for 8 weeks for my camera repair now, they're still waiting for parts from oversea....that's what you get if you live in the bundu...

Last edited by altopiet; 05-16-2014 at 05:59 AM.
07-06-2014, 08:19 AM   #15
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QuoteOriginally posted by Jo Mellor Quote
After using my camera for a year with no problems it suddenly started underexposing images. I now have to take 3 identical images one after the other quickly, the 1st one is usually vastly underexposed and the other 2 are ok, however the exposure information on all 3 images is identical. I've had to put up with it several months now and it's irritating as I miss capturing a good shot sometimes if it is of something moving. I have also had endless issues with dust on the sensor and have to constantly clean it, even when I've not changed lenses, in fact most of the time I'm now to worried to change them. The dust issue has been a major problem for me after only a few weeks of owning the camera. I've always loved Pentax but feel really disillusioned. I'm good with a camera and fully understand how to use it but am in no way technicalso it's really frustrating reading through reams of suggestions and info on the camera as I never have the mindset to understand the 'boring' stuff lol. All I want to do is take pics without glitches!
Another newbie here, came to look for answers about this exact problem! I've also had my camera for about a year and it's started doing it recently, but is gradually getting worse. It happens regardless of lighting - I've even tried completely overexposing images but still get some underexposed ones. Did you manage to find out what was causing it?

Or does anyone else have advice on this? I'm wondering if I should go to a repairs shop to have them look at it - I am really starting to panic now because I have an event and wedding to shoot next week and am worried my camera will let me down. Like an idiot I didn't buy the extended warranty so I can't send it back to Pentax (until I can afford to pay, anyway).
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