Struggling with camera light meter

[nixgeek]

Hi All,

So I decided it was time to break out the camera this morning and start taking pictures from the garden. Something I noticed very quickly was that the light meter in the camera (set on matrix mode) would indicate dead centre (I assume this means ideal light), yet the picture would be under exposed.

Here is an example, where the first picture 1/80 was dead centre, and the second should have been overexposed.
_DSC0340 by my0373, on Flickr

The second I reduced the shutter speed to 1/50 and it came out much better (to my eyes anyway).

_DSC0339 by my0373, on Flickr

I still don't fully understand white balance, and I'm going to order a set of reference cards to help me practice. However, I noticed there is an exposure compensation button on the camera. I wondered if that could just be setby hand until i'm happy with the exposure ?

The camera is a Nikon D5100 with a Tamron 18-270 lens, the weather was really sunny. I wasn't using a tripod.

I'm going back out this afternoon to take some more pictures with both spot mode and centre weighted metering set.

Any advice to help me take a better-exposed picture would be greatly appreciated.

 

[photo1x1.com]

Hi again .
The thing with centre weighed metering is: the camera bases the exposure on the entire frame, but there is more weight on the centre. Since your centre is rather bright (lower part of the sky), the camera exposed a little darker than might be perfect to your eye. Probably even matrix mode might have underexposed a little. There is only so much our cameras can do to help us. For example, if you had a black rabbit on white snow, the camera would see that there is a huge lot of white and would completely underexpose the rabbit.
We just have a discussion going on about spot metering here: Need some advice please. It is a little different than yours, but it might help you understand spot metering too because with spot metering it makes a big difference where your spot is aimed at. In your example, it would make a huge difference whether you would point the spot at the rather bright clouds, or at the darkest tree.

 

[smoke665]

Something I noticed very quickly was that the light meter in the camera (set on matrix mode) would indicate dead centre (I assume this means ideal light), yet the picture would be under exposed.

No the camera was setting the exposure for the "average" of the scene. You need to read up on Metering Modes Explained

Any advice to help me take a better-exposed picture would be greatly appreciated.

Let me give you a very simple answer to your question- Set your camera to MANUAL, then learn the basics of the "exposure triangle", and how to relate it to the scene you are shooting The Exposure Triangle: Understanding How Aperture, Shutter Speed, and ISO Work Together When you learn the basics you'll be better able to determine which of the automated features available on your camera you want to use.

 

[snowbear]

To help understand the metering modes, try taking a photo of the same scene (same focus point, same lighting) with each mode. Pick a mid-toned area for the center.

White balance is simply adjusting the colors to match the light's color temperature. One exercise is to photo a white object in daylight using each of the white balance presets to see how color is rendered. Then do the same indoors, in shade, etc. I shoot raw, so the WB settings don't really matter, but I generally use auto and set the WB in Lightroom.

 

[Bebulamar]

The matrix metering system has a mind of its own. You can either trust it and it does a good job in a large percentage of situations or you can alter what it did like you did. The thing about the matrix metering is that it's very difficult to tell when it's not going to do a good job and how much you need to compensate before you actually take a test shot. With center weighted metering you can guesstimate the amount of compensation before you take the shot as the metering pattern of CW is well defined.

 

[nixgeek]

No the camera was setting the exposure for the "average" of the scene. You need to read up on Metering Modes Explained

Thanks.

Let me give you a very simple answer to your question- Set your camera to MANUAL, then learn the basics of the "exposure triangle", and how to relate it to the scene you are shooting The Exposure Triangle: Understanding How Aperture, Shutter Speed, and ISO Work Together When you learn the basics you'll be better able to determine which of the automated features available on your camera you want to use.

I've been using manual mode and trying to control the exposure, but I'm still learning to balance these things out though. I will definitely re-read it though, so thank you (and for your help on my other post also).

Thanks again everyone.

 

[nixgeek]

The matrix metering system has a mind of its own. You can either trust it and it does a good job in a large percentage of situations or you can alter what it did like you did. The thing about the matrix metering is that it's very difficult to tell when it's not going to do a good job and how much you need to compensate before you actually take a test shot. With center weighted metering you can guesstimate the amount of compensation before you take the shot as the metering pattern of CW is well defined.

The LCD on the back of the camera seems to illuminate the picture, so it's only when you get it on a decent sized screen you can tell how light / dark the actual picture is. It sounds like I need to understand the metering better, and how to (or not to) compensate for it. Thanks for helping me out!

 

[nixgeek]

Hi again .
The thing with centre weighed metering is: the camera bases the exposure on the entire frame, but there is more weight on the centre. Since your centre is rather bright (lower part of the sky), the camera exposed a little darker than might be perfect to your eye. Probably even matrix mode might have underexposed a little. There is only so much our cameras can do to help us. For example, if you had a black rabbit on white snow, the camera would see that there is a huge lot of white and would completely underexpose the rabbit.
We just have a discussion going on about spot metering here: Need some advice please. It is a little different than yours, but it might help you understand spot metering too because with spot metering it makes a big difference where your spot is aimed at. In your example, it would make a huge difference whether you would point the spot at the rather bright clouds, or at the darkest tree.

Thank you, the discussion you have mentioned looks like it might answer some of my questions before I post them. Thanks!

 

[smoke665]

Expanding on an earlier comment. The EXIF on your 1st shot shows 55 mm 1/80, f/20, ISO 100. My personal opinion first of all would have been to get the shutter speed up to at least 1/125 or better to minimize camera shake, by raising the ISO or opening the aperture. Every lens has an aperture sweet spot, usually in the f/8-10 range. When you go over that what you possibly gain in DOF you lose in sharpness. Without going into a lot of detailed discussion, likely to only confuse you at this point here's another good reference for the beginner. How To Find Your Lens' Sweet Spot: A Beginner's Guide to Sharper Images

 

[smoke665]

The LCD on the back of the camera seems to illuminate the picture,

I'm not a Canon person really, so this may not apply to the 6i, but I know that earlier models were like most models on focusing. If you use the LCD the camera AF uses contrast detection to focus, while the viewfinder uses phase detection, a much more accurate and quicker focusing method.

 

[fmw]

I would meter that scene with matrix metering aimed below the sky. Then I would hold the reading with half shutter, recompose and shoot. The meter wants to produce 18% medium gray. Metering the sky would render medium gray for the sky and underexpose the residential horizon. If you can determine where in the subject medium is then that is all you have to do. If you are shooting a black cat in a coal bin you will need to adjust from your meter reading because it will certainly overexpose the cat no matter what metering mode you use.

 

[nixgeek]

Just to say thanks to everyone that replied. So after I posted last time, I took more pictures and pretty quickly realised it was the way I was using the metering. To cut a long story short, I was just using matrix metering for everything. That, unsurprisingly gave me some unpredictable results.

I read the article on metering, which now makes much more sense, and i've discovered on spot mode, I seem to get a much more accurate light meter reading, however in centre weighted metering it gives a better balance overall, I just need to compensate by 3 - 4 notches on the light meter (overexposed), and I get a great pic.

I wouldn't say i've cracked it, but I'm much further than I was, so thanks.

Here are some of the images I've been playing with.

This was centre weighted metering (light sensor was bang in the middle), but given the difference in light between the sky and the ground it makes sense why it's such a dark pic.
_DSC0202 by my0373, on Flickr

This is the same (or very close) pic with the light meter 3 notches to the left (overexposed)
_DSC0203 by my0373, on Flickr

This was taken at the same time in spot mode with the field being the target, and the light meter in the middle.
_DSC0204 by my0373, on Flickr

Thanks for your help all, I think I understand what I have to work on!

 

[nixgeek]

Expanding on an earlier comment. The EXIF on your 1st shot shows 55 mm 1/80, f/20, ISO 100. My personal opinion first of all would have been to get the shutter speed up to at least 1/125 or better to minimize camera shake, by raising the ISO or opening the aperture. Every lens has an aperture sweet spot, usually in the f/8-10 range. When you go over that what you possibly gain in DOF you lose in sharpness. Without going into a lot of detailed
discussion, likely to only confuse you at this point here's another good reference for the beginner. How To Find Your Lens' Sweet Spot: A Beginner's Guide to Sharper Images

Thank you, I've been too afraid of dots >1600 ISO. I need to man up, and start figuring out what gives the best results for my camera and my lens in the environment.

Thanks!

 

[smoke665]

I routinely push up to 800 ISO with little noise issues. If there are they're easy to clean up post. At 12800 and above it requires more clean up,. At levels of ISO 400 or below I'm not sure you would even notice.

 

[davidbeckphoto]

Why are you using a light meter? Just bring a digital camera, get it right on the histogram, and use the same settings for your film camera? It's only cheating if you want to make things harder for yourself.