Light Metering Mode K20D

mattmiles · 12-02-2009, 01:43 PM

Hello,

As a newbie to photography I have been avidly reading up on exposure, aperture, ISO and various other things.

I came across an article about using the Light Meter on the Camera. I was wondering if anyone could explain how to do this on a Pentax K20D and explain the significance of doing this.

Any help would be hugely appreciated.

Thanks

Matt

**Ash** · 12-02-2009, 02:04 PM

OK, I see the metering question comes up here...

In auto and semi-auto modes, the camera uses its in-built light meter to gauge how much exposure it should provide for the image it's capturing. It's in manual (M) mode that the meter gives you what you would expect in the old film cameras - an indicator for exposure level. This is best understood once you've grasped the concept of the exposure triad and are comfortably using the semi-auto modes like Av.

Hope this helps.

Marc Sabatella · 12-02-2009, 03:48 PM

Originally posted by mattmiles

I came across an article about using the Light Meter on the Camera. I was wondering if anyone could explain how to do this on a Pentax K20D and explain the significance of doing this.

I don't understand the question. You say you've been reading about shutter speed and aperture and so forth - what specific questions about the meter in your camera do you have? Are you wondering how the exposure modes work. The meter tells you what shutter speed to use for the selected aperture in Av mode; it tells you what aperture to use for the selected shutter speed in T mode, and in P mode it picks both for you. You use exposure compensation to override those suggestion. In M mode, the meter doesn't suggest anything - it simply tells you whether the settings you have made will result in over or under exposure (and by how much). You can hit the Green button to cause the camera to change shutter speed or aperture or both to yield the same exposure it would have in Av, Tv, or P modes. That's about it.

Ratmagiclady · 12-02-2009, 07:55 PM

On a K20D, there are of course three metering modes. Spot, average, and 'matrix.'

Worry about spot, later. The 'matrix' mode is the one in green, which you can select via the switch under the dial on the left side of the camera. This is the 'smartest' metering mode: it looks at several areas of what you see in the finder and calculates them separately according to what some engineers figured would be likely to add up to a typical exposure. It will usually do quite well.

In between these is the 'average' metering mode: this is what we used to call 'Center-weighted' metering in the old days. Here, the light meter will calculate an exposure for you based on a single reading, taking the center of the frame as well as usually a bit lower into account much more than the top corners as you hold a vertical shot. This is a pretty 'classic' mode of metering, back when things were done by optics rather than computers. (Spot simply makes a flat reading out of the very center of the frame)

You may use either average or matrix metering with pretty good certainty under most conditions. For a beginner, I would advise the matrix setting unless you are in a darker condition with, say, streetlights. (this can fool the computer) If you use the average setting and pay attention to what the meter tells you, you'll learn more about what's going on, though.

Last edited by Ratmagiclady; 12-02-2009 at 08:01 PM.

12-02-2009, 01:43 PM	#1
mattmiles New Member Join Date: Oct 2009 Posts: 22	Light Metering Mode K20D Hello, As a newbie to photography I have been avidly reading up on exposure, aperture, ISO and various other things. I came across an article about using the Light Meter on the Camera. I was wondering if anyone could explain how to do this on a Pentax K20D and explain the significance of doing this. Any help would be hugely appreciated. Thanks Matt

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12-02-2009, 02:04 PM	#2
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	OK, I see the metering question comes up here... In auto and semi-auto modes, the camera uses its in-built light meter to gauge how much exposure it should provide for the image it's capturing. It's in manual (M) mode that the meter gives you what you would expect in the old film cameras - an indicator for exposure level. This is best understood once you've grasped the concept of the exposure triad and are comfortably using the semi-auto modes like Av. Hope this helps.

12-02-2009, 03:48 PM	#3
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by mattmiles I came across an article about using the Light Meter on the Camera. I was wondering if anyone could explain how to do this on a Pentax K20D and explain the significance of doing this. I don't understand the question. You say you've been reading about shutter speed and aperture and so forth - what specific questions about the meter in your camera do you have? Are you wondering how the exposure modes work. The meter tells you what shutter speed to use for the selected aperture in Av mode; it tells you what aperture to use for the selected shutter speed in T mode, and in P mode it picks both for you. You use exposure compensation to override those suggestion. In M mode, the meter doesn't suggest anything - it simply tells you whether the settings you have made will result in over or under exposure (and by how much). You can hit the Green button to cause the camera to change shutter speed or aperture or both to yield the same exposure it would have in Av, Tv, or P modes. That's about it.

12-02-2009, 07:55 PM	#4
Ratmagiclady Veteran Member Join Date: Nov 2008 Location: GA Photos: Gallery \| Albums Posts: 13,563	On a K20D, there are of course three metering modes. Spot, average, and 'matrix.' Worry about spot, later. The 'matrix' mode is the one in green, which you can select via the switch under the dial on the left side of the camera. This is the 'smartest' metering mode: it looks at several areas of what you see in the finder and calculates them separately according to what some engineers figured would be likely to add up to a typical exposure. It will usually do quite well. In between these is the 'average' metering mode: this is what we used to call 'Center-weighted' metering in the old days. Here, the light meter will calculate an exposure for you based on a single reading, taking the center of the frame as well as usually a bit lower into account much more than the top corners as you hold a vertical shot. This is a pretty 'classic' mode of metering, back when things were done by optics rather than computers. (Spot simply makes a flat reading out of the very center of the frame) You may use either average or matrix metering with pretty good certainty under most conditions. For a beginner, I would advise the matrix setting unless you are in a darker condition with, say, streetlights. (this can fool the computer) If you use the average setting and pay attention to what the meter tells you, you'll learn more about what's going on, though. Last edited by Ratmagiclady; 12-02-2009 at 08:01 PM.