Cam and Cheese

So you've had your fun with your new dSLR. You've learned about the body and lenses. But now you want to go onto the next challenge: Shooting in manual mode to create your own creative and wonderful works of art. There are three things that you will need to adjust - aperture, shutter speed, and ISO - the "photographic triangle". These three allow you to change the lighting for any picture you want. No more messing around with auto mode which changes all three settings for you. If you see a picture that Auto mode won't allow you to take, you need to adjust the settings yourself to get the picture you want. This is where Manual mode is great. Adjusting one of the three will cause a change in the amount of light that will go into your camera.

This tutorial will be a basic one teaching you what each of the corners of the photographic triangle is, and how they relate to each other.

The Photographic Triangle

Aperture - determines how big the opening in your lens is when you take a picture. The bigger the hole, the more light that gets into your camera. Keep in mind that aperture is an inverse number. So when you see a number like 4 it is actually f/4. That being said, the smaller the number the larger the opening. An aperture of f/4 will allow more light into the sensor than f/8. Lenses can go from f/1 (amazingly) all the way up to f/32. You will often hear terms such as "wide" and "narrow", or "large" and "small". These just denote how big the opening of the lens is. The aperture restrictions rely solely on your lens. The bigger/wider the aperture, the more expensive the lens is going to be.

Shutter Speed - the amount of time it takes for your lens to open and close when you take your picture. The slower the shutter speed, the more light gets into your camera. This is also usually an inverse function. Most cameras display a number like 100 or 200, but this is actually 1/100th or 1/200th of a second. Slower shutter speeds usually display a " (quotation symbol) denoting a second. These numbers are very long shutter speeds. The length of the shutter speed is restricted by your dSLR. Typically, your camera body will allow you to do Bulb (where you control how long the shutter is), 30 seconds all the way down to 1/8000th of a second. The more expensive the camera the faster you can shoot.

ISO - Originally ISO was a standard used with film. Lower ISO (50, 100, 200) film coincided with lower sensitivities to light. Higher ISO film (800, 1600, 3200) is more sensitive to light. The same notation transferred over to the digital world. You should expect to see ISO100 all the way up to ISO3200. Some cameras even have up to ISO12800! Be careful though, the higher the number, the more grainy your pictures may turnout especially if you underexpose and try to brighten up your picture in post work. Another thing to keep in mind is that cameras with cropped sensors are more prone to having grainy images at higher ISOs. This is because cropped cameras have smaller photo sites on their sensors. Generally speaking, the larger the photo sites on a given sensor, the less the noise. 

Putting it all together

In the middle of your viewfinder you should see a bar scale that displays something like  + | | 0 | | -  (for Nikon) or -2 | | -1 | | 0 | | 1 | | +2 (for Canon) . If you've never used manual, aperture priority, shutter priority, or program mode before, you've probably never had to pay attention to this bar, or maybe you have never seen this bar. This is your camera's built-in light meter. There is an arrow or a set of bars below this bar scale. Being on the + or positive side means that your light meter thinks that the exposure being measured will be brighter than 18% grey. Being on the - or negative side, your light meter thinks that the exposure being measured will be darker than 18% grey. Being on the 0 mark or the middle mark means that your light meter is measuring the exposure at 18% grey. For the most part, you want your arrow to be at 0. If the scene you are capturing is relatively dark you want to make an exposure that gives your light meter a reading in the negative side of the meter. Conversely, if the scene you are capturing is relatively bright you want to make an exposure that gives your light meter a reading in the positive side of the meter. To add to all of this you also have to be aware that your dSLR has several different metering modes. These metering modes tell the camera what areas of your scene will be measured for light and, in some cases, the areas that won't be measured at all. Read your camera's manual to see the different types of metering modes your camera has and try them out. Experiment with different settings to see what happens if you overexpose a picture of a black object or underexpose a picture of a white object.  

Here are example viewfinders for a Nikon D80 and a Canon 40D.

Now that you have a basic idea of what each corner of the photographic triangle is and your light meter, we have to put them all together to create the proper exposure. And it's basically all simple math. This will be an easy tutorial, and we won't get into "stops". That will be saved for another tutorial. All you really need to know how to do is move up and down. Increase this and decrease that. I won't be dealing with real numbers here.

So say your light meter says your image is over exposed (your bars or arrow is in the Positive + side). How do you adjust your Aperture, Shutter Speed, or ISO? There are a bunch of ways, use any combination of the following. Change one setting or change all three. It's up to you, for now. What you want to do is reduce the amount of light getting into your sensor.

1. Make your aperture smaller/narrower. If you are at f/4, change your aperture to f/5.6 and keep going.
2. Increase your shutter speed. If you are at 1/200 go to 1/250. Keep increasing the speed if you have to.
3. Reduce your ISO. If you are at ISO200 go to ISO100.

Now, if your light meter says you are under exposed (your bar or arrow is in the Negative - side). Again, use any combination of the options below.

1. Increase your aperture. If you are at f/5.6 go to f/4.
2. Decrease your shutter speed. If you are at 1/250 go to 1/200 and keep going.
3. Increase your ISO. If you are at ISO100 go to ISO200.

Note that changing these settings will have other effects on your final image. But that's saved for another tutorial. For now, just keep trying to shoot in manual and properly expose your pictures.