Using your Light Meter and Histograms
Why shoot in manual? Well, have you ever tried using the AV (aperture) priority mode and found that your photos were blurry? That’s just one of many reasons to shoot in manual. You can learn to make the decisions instead of allowing the camera to choose for you. You are smarter than your camera! Shooting in manual mode can seem a bit daunting at first, but once you figure out how to use some of the tools at your disposal (the in-camera light meter and the histogram) you will have a much easier time! Check out this youtube video on Shooting in Manual Mode: http://www.youtube.com/watch?v=VlSuInza16E and this video on Exposure Basics: http://www.youtube.com/watch?v=KQw28-3LEU4
First let’s do a quick review:
ISO: Your camera’s sensitivity to the light. The brighter it is where you’re taking your photos, the lower your ISO number needs to be. Therefore if it’s dark and/ or there’s not a lot of light, then your ISO needs to be higher. The result of an ISO that is too high is grain.
Aperture: The term used to describe what is simply the opening in the lens that light travels through to reach the camera’s sensor or film. This opening can be set at different sizes. A small f stop number is a wide aperture and a high f stop number is a narrow aperture. The wider the aperture (opening) the more light reaches the sensor/film.
Shutter Speed: The length of time that the shutter is open, allowing light to reach the sensor of the camera. The longer the shutter is open, the more light enters your camera, and the shorter the shutter is open, the less light enters your camera
The Manual Exposure Goal: Use your in-camera light meter in manual mode to help you choose your settings in order to get a good exposure. When exposing your photos manually (with the light meter in your camera), the general goal is to get the little indicator as close to the “0” as possible. Check out this video on Understanding Stops: http://www.youtube.com/watch?v=bv0vXD16_lA
Metering Modes: Check out this short video that explains metering modes, http://www.youtube.com/watch?v=Axt9zLxdE8s
Evaluative/Matrix Metering: Aim to get the little indicator as close to the “0” as possible.
Spot Metering: This is a more advanced metering mode. If you are shooting a portrait with someone with light skin, aim the center dot on the skin (get close up if necessary) and adjust your settings to have your metering at one stop +1 exposure. On Canon cameras this is to the right of the “0” and on Nikon cameras this is to the left. This is especially useful for backlighting.
~Getting in the habit of being in manual~
When getting ready to take a photo try to get in the habit of…
Step 1: Check your light and set your ISO
Step 2: Evaluate the Moment: Are you looking to capture motion or depth of field? Set aperture or shutter speed in order of priorities.
Step 3: Look at your meter and change settings accordingly The more time that you spend doing this, the faster and more automatic it will become. Play with your dials, if the indicator is moving away from the”0″ then move the dials in the opposite direction. Practice, practice, practice.
Histograms and Blinkies :
A histogram is a graph that shows the distribution of pixels from dark to light. You can use a histogram view on your LCD screen to help you assess exposure. If there is a tall spike at one end or the other, that means there is no detail in the whites or blacks. If you turn your “blinkies” on, your LCD playback will show the lost detail areas with a blinking area. If you are losing detail in the shadows you would have to increase your exposure (slow down your shutter speed, increase the ISO, or open your aperture-choose a lower f/number). If you are losing detail in the highlights, you would have to decrease your exposure (increase the shutter speed, decrease your ISO, or close down your aperture- choose a high f/ number). Sometimes you won’t care if you are losing detail if it’s in a place that doesn’t really matter (like a white sky in a back-lit image). But you don’t want to lose detail in important areas like skin! If you have “blown out” a highlight, no editing will be able to get it back because there is no data there!
Now it’s Your Turn
Switch your camera to the M (manual setting). Set your ISO. Get in camera ready position. Keep your elbows in and your camera close (helps to avoid camera shake). Aim your camera in different areas of light. Notice how your meter changes in response to the amount of light hitting the sensor. If there is a lot of light, you will notice the indicator hovering on the + side of the meter. If there is not a lot of light, it will be on the – end.
This is a good time to use the Exposure triangle cards (Aperture, Shutter Speed, ISO) that were handed out a few months ago. If you don’t have these click the name/ link to get a print out pdf. They are a great reference for figuring out general guidelines for ISO, aperture, and shutter speed.
*Tip: If you’re having a really hard time getting the little indicator to move toward the “0” it can be a good idea to put your camera on automatic mode and see what it’s setting the exposure at. This will give you a rough idea of possible settings to try, just remember to compensate if the exposure doesn’t look right. Remember that there’s a reason why manual exposure is always better, people will always be smarter than cameras. Adjust your shutter speed and your aperture to achieve a correct exposure.
Here is all the info in the form of a handout (that we worked with at our Metering workshop). We will be adding more information in the coming days, but this should help you out for starters!