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01-17-2011, 05:20 PM   #1
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Another Underexposure...please help

Hi, just got a Pentax K-X last week and am unable to get a proper exposure. I will be using my camera 80% of the time on automatic. I know I could adjust on manual, but do not want to as yet. My brother uses his Sony camera ONLY on auto and he gets great pics with no adjustments. Here is mine, let me know if I am missing something simple. Thank you in advance, I appreciate any help. Again I want to use auto mode, I mean you should be able to, that is the point of it. Don't mind me I am just so annoyed, almost a week and still no good pics. Thanks


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Last edited by PentaxKX-2011; 01-17-2011 at 05:27 PM.
01-17-2011, 05:27 PM   #2
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When the weather is overcast or when there is a lot of snow in your picture you'll typically have to use a positive EV correction, +0.5 to +1.5 EV depending.
01-17-2011, 05:32 PM   #3
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Hi there.
Welcome here.
Unfortunately, even auto modes can get it wrong, but for good reason (explained later). Not only that, but results are also lens-dependent - some produce darker results than others. For example, the kit lenses are known to underexpose when on fully auto modes (I'm assuming you're using the green AutoPict mode).

Firstly, you need to understand how exposure is calculated by the camera and why Pentax has a bias towards relative underexposure on a fully auto mode in those settings. It is much better to expose for shadow details and have an overall darker image than to overexpose and blow out highlight detail. So Pentax metering tends to 'underexpose' as a result, but it works out to be an advantage for post-processing.

A white/bright scene will be seen by the camera as requiring less exposure in order to average out the image to come out more grey, so in those settings (such as snow) it is important to go to P mode and increase the exposure bias to +1 to +2 in order to overcome this metering issue (Green AutoPict modes will not allow you to do this). If this is all too much, have a read of these articles:

https://www.pentaxforums.com/forums/photography-articles/39743-understanding-...-kit-lens.html
https://www.pentaxforums.com/forums/photography-articles/23232-learning-basic...echniques.html
01-17-2011, 05:39 PM   #4
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QuoteOriginally posted by PentaxKX-2011 Quote
Hi, just got a Pentax K-X last week and am unable to get a proper exposure. I will be using my camera 80% of the time on automatic. I know I could adjust on manual, but do not want to as yet. My brother uses his Sony camera ONLY on auto and he gets great pics with no adjustments. Here is mine, let me know if I am missing something simple. Thank you in advance, I appreciate any help. Again I want to use auto mode, I mean you should be able to, that is the point of it. Don't mind me I am just so annoyed, almost a week and still no good pics. Thanks


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Really? All I need to do is slide that bar? I know there are different ways to use auto, I just feel pressed for time as far as learning them cause I only have a few more days to return the camera if it is defective, but I guess I am the problem. Thank you very much.

01-17-2011, 05:44 PM   #5
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QuoteOriginally posted by Ash Quote
Hi there.
Welcome here.
Unfortunately, even auto modes can get it wrong, but for good reason (explained later). Not only that, but results are also lens-dependent - some produce darker results than others. For example, the kit lenses are known to underexpose when on fully auto modes (I'm assuming you're using the green AutoPict mode).

Firstly, you need to understand how exposure is calculated by the camera and why Pentax has a bias towards relative underexposure on a fully auto mode in those settings. It is much better to expose for shadow details and have an overall darker image than to overexpose and blow out highlight detail. So Pentax metering tends to 'underexpose' as a result, but it works out to be an advantage for post-processing.

A white/bright scene will be seen by the camera as requiring less exposure in order to average out the image to come out more grey, so in those settings (such as snow) it is important to go to P mode and increase the exposure bias to +1 to +2 in order to overcome this metering issue (Green AutoPict modes will not allow you to do this). If this is all too much, have a read of these articles:

https://www.pentaxforums.com/forums/photography-articles/39743-understanding-...-kit-lens.html
https://www.pentaxforums.com/forums/photography-articles/23232-learning-basic...echniques.html
I guess I am making more out of this than I should. You guys are talking about only a couple simple adjustments of the camera, You know? I just got to chill a little. Thanks for helping, this forum is great!!
01-17-2011, 05:46 PM   #6
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The sky and the snow are well under control, ie. not blown out. Like they say, +1 or so ev will brighten things up.
01-17-2011, 07:18 PM   #7
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Use P, not Green mode, and study up on exposure compensation as suggested. Knowing what the meter is thinking - and correcting for it if needed - is far more important that the actual mode used, such as M, Tv or Av.

01-17-2011, 07:33 PM   #8
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Like others have said, its your scene that is causing the under exposure. If you take a photo on auto indoors or anywhere that doesn't have a lot of white (snow, clouds) the photo will look properly exposed. If you shoot more photos in those conditions you would need to bump up the EV at least +0.5.
01-18-2011, 03:16 AM   #9
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QuoteOriginally posted by SpecialK Quote
Knowing what the meter is thinking - and correcting for it if needed - is far more important that the actual mode used, such as M, Tv or Av.
This is very well expressed:

A camera can't read your mind and know which parts of a scene you want to optimally expose for. For all the camera knows, the sky is your main subject, and everything else is meaningless.

You'll learn to look at the range of brightnesses and grey levels in a scene and know when you'll have to use some form of compensation.

A girl's torso against a grey wall, no. A girl's torso with the bright sun behind her, yes. Same subject, but the other light elements entering the lens and affecting your metering are vastly different.
01-18-2011, 09:36 AM   #10
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Thanks everybody!!! I took pics today and they are much better thanks to the advice on here. We had a snow and ice storm so that is great, just what I needed to practice on. I used the scale with the histogram and though they are not perfect, there is a big improvement. At least I know there is hope.

After I get this mastered I will learn the manual mode, but for the most part I want auto, nice to know both though. Thanks soo much!!
01-18-2011, 03:54 PM   #11
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I'd suggest you get to know the P mode.
It's for all intensive purposes "auto" but you have control of the exposure compensation when desired.
01-19-2011, 06:00 AM   #12
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Investigate the histogram the camera can show you. Look at it for good and bad exposures, get to see what is right and what is wrong. I find it a great help in 'non-standard' conditions.
01-19-2011, 06:11 AM   #13
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QuoteOriginally posted by cats_five Quote
Investigate the histogram the camera can show you. Look at it for good and bad exposures, get to see what is right and what is wrong. I find it a great help in 'non-standard' conditions.
+1

Although it looks intimidating, learning how to look at the histogram and understand what it is telling you is probably the single most useful thing you can learn about using your camera.
01-19-2011, 08:45 AM   #14
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+1

Although it looks intimidating, learning how to look at the histogram and understand what it is telling you is probably the single most useful thing you can learn about using your camera.
That is what I have been doing the last couple of days. Using the histogram and bumping that scale up a notch is really making a difference. It is getting fun taking pics now, instead of annoying!! Thanks for the tip. Thanks to everyone, you guys really helped out.
01-19-2011, 08:53 AM   #15
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Just to clarify things a bit, your camera is stupid. It has likely been programmed to make the average brightness of a scene be 18% of the camera's maximum brightness. That's pretty gray actually.

If you take a photo of a bright white wall it will come out dingy gray. If you turn on more lights & reshoot the photo will still be dingy gray (the camera forces the picture's average brightness to 18%). Snow & a bright cloudy sky are just as bad as a white wall.

That's why you have to add brightness (positive exposure compensation) when most of the scene really is bright.

Perhaps the magic 18% is related to the fact that an average caucasian face has a reflectivity of about 18%. If I were marketing cameras to a caucasian crowd I'd want to make sure photos of faces came out ok.

Dave

PS Women's faces are brighter. Maybe due to makeup fashions?
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