ADVANCED EXPOSURE  

THE LIGHT METER REVISITED Any time you half press the shutter button, the light meter activates. As we know, it measures the light in your scene, and calculates a shutter speed and aperture. ( And ISO, if your camera is set to auto ISO) You already know what your light meter does, but what do you do, when it encounters issues in your photo? THE LIGHT METER REVISITED

MATRIX METER: It divides your image into a grid and takes a separate meter reading for each cell in the grid. These cells are then analyzed to determine an exposure setting. The total number of cells is not nearly as important as how well the camera processes the data it gathers from those cells. METERING MODES

CENTER – WEIGHTED AVERAGING: A variation of Matrix metering, this also divides your image into a grid of cells, but when analyzing the readings, it gives preference to the cells in the MIDDLE of your image. Designed to be used when your subject is in the middle of the frame. METERING MODES

PARTIAL METERING: This setting only meters cells in the middle of your image, the size of the area is only about ten percent of the total scene. Provides a way to address backlighting troubles, because the partial meter completely ignores the cells that sit outside the metered area. METERING MODES

SPOT METERING: Measures only a small area of your image, usually the center, the metering from this area is the only information used to calculate an exposure. This area is much smaller than what a partial meter provides, and it doesn’t take any other areas of the image into account. Provides precise readings, especially to very small details. METERING MODES

http://www.youtube.com/watch?v=Jh_Fc4JKOBw METER MODES

LOCKING EXPOSURE Frame a shot with a bright subject Press and hold the shutter button, take note of exposure settings Reframe so the majority of the frame is filled with dark areas and note if the exposure settings change If your exposure settings do not change, then you know your camera locks exposure when the shutter button is held down. LOCKING EXPOSURE

WHAT YOUR LIGHT METER METERS Your light meter, meters/measures the luminance of light reflected by your subject. The most important thing you need to know about your camera’s light meter is that it always assumes that it is pointed at something that is 18% gray. In other words, your light meter calculates an exposure recommendation that will accurately reproduce middle gray under your current lighting. A typical scene reflects 18% of the light it hits, this assumption is fairly accurate. WHAT YOUR LIGHT METER METERS

To get the best result, you’ll want to meter off something that is middle gray, such as an 18% gray card. Please note, that this assumption will not always be correct, some instances might have a subject that is darker than the “18%” gray mark which can cause you metering settings to be confused.

THE RISK OF OVER/UNDER EXPOSURE When you start messing with the camera’s carefully calculated exposure settings, you risk over/under exposing your scene. Having said that, sometimes it is ok to over/under expose a highlight to get better tonality in your subject. THE RISK OF OVER/UNDER EXPOSURE

Exposure Compensation Allows you to specify an amount of over/under exposure. Most cameras let you adjust exposure compensation in ½ or 1/3 – stop increments. This lets you think in purely relative terms with no concern for shutter speed or aperture. Exposure Compensation

Exposure compensation

Exposure Compensation If you decide your scene needs to be underexposed by a stop or properly render some black objects, simply press the minus exposure button twice. Your camera will meter as normal to determine its usual adequate exposure. Take note that on automatic mode will not provide you access to exposure compensation, so you’ll have to switch to program mode. Exposure Compensation

Exposure Compensation and Program Shift Program Shift, lets you automatically change between equal exposures after the camera has metered. In other words, you can switch quickly to a different shutter speed or aperture, while maintaining the correct exposure. Ex. You decide to meter and then use Program Shift to switch to a wider aperture because you want a shallower depth of field. Essentially your metering first, then simultaneously moving to your shutter speed or aperture setting. Exposure Compensation and Program Shift

Controlling Exposure with your Light Meter Using a built in light meter, you can force an over or under exposure by pointing the camera at something darker or lighter. Meter off lighter subject = under expose Meter off a darker subject = over expose Since your camera will lock exposure at the same time it locks focus, MAKE SURE you meter off something that is the same distance as the object you want in focus. Controlling Exposure with your Light Meter

In a Priority mode, you chose either the shutter speed or the aperture you want, and the camera calculates the corresponding value that is required to ensure a good exposure. Typically you’ll want to select a shutter priority when you want to control motion and Aperture priority when you want to control depth of field. Priority Modes

Manual mode gives you control of both aperture and shutter speed. You can still use your light meter in manual mode. The same display that is usually used to show exposure compensation will serve as a guide to whether or not your exposure is good. Priority mode is the mode you should prefer over manual mode. Manual Modes

The LCD screen on your camera greatly increases the brightness, and possibly color contrast and saturation in any image. This is due in part that the camera’s creator wants you too be able to see your picture in direct sunlight. A built in Histogram, allows you to determine if your camera has certain exposure problems. IN CAMERA HISTOGRAMS

The histogram flashes any areas that have clipped highlights or shadows. http://www.youtube.com/watch?v= DXK6ena5Fk8 IN CAMERA HISTOGRAMS

A Histogram is a simple graph of the distribution of all tones in your image. A Histogram provides a bar chart showing how much of each shade of grey is present in the image, with each vertical line representing one shade. Black is at the far left, White is at the far right. HISTOGRAM DEFINED

In addition to spotting over and underexposed problems, you can use your camera’s histogram to determine the amount of contrast in your image. ASSESSING CONTRAST

THREE CHANNEL HISTOGRAM The camera shows a separate Histogram for each color channel (Red, Green, and Blue) If the three channels are way out of registration there's a chance your image has a white balance issue. THREE CHANNEL HISTOGRAM

Bracketing as you should already know, is the process of shooting extra exposures above and below your target exposure to give yourself a margin of error in your exposure calculation or adjustment. The easiest way to bracket is with your exposure compensation control. Take a shot, dial in an underexposure, and then shoot again. BRACKETING

As always with exposure compensation, you'll have no way to control how the camera achieves its over or under exposure. Bracket when you are taking photos of landscapes, still lifes, portraits, and other nonchanging static scenes. BRACKETING

Find it in menu, Press the shutter button, the camera shoots an image at the recommended metering and then automatically adjust to one stop of underexposure and one stop of over exposure. AUTO BRACKETING

Portrait Mode: Blurs out background to focus on the subject Portrait Mode: Blurs out background to focus on the subject. You can achieve this by using a wider aperture. Landscape Mode: Large depth of field/small aperture, to lock focus on the object at hand. Sand and snow Mode: White for snow will need to be a little overexposed, so it doesn’t end up gray in your final image. SCENE MODES REVISITED

IMAGE PROCESSING PARAMETERS REVISITED These are the settings that you would improve in your picture, after it has been taken. Two different names for them are “Picture Styles” and “Picture Controls” Try to think of processing parameters as image editing applications (PhotoShop) IMAGE PROCESSING PARAMETERS REVISITED

Say you are walking down the street and you see a game of soccer being played, what should you do with your shutter speed, ISO, and aperture? - Fast Shutter Speed (motion) - High ISO (depending on lighting) - Small Aperture, to catch the player in motion, this is not a landscape photo, obviously. EXPOSURE STRATEGY