Camera Basics Refresher
Well, it’s a new year and Christmas has come and gone. With the popularity of photography lately I’m sure that there will be some readers who have received the gift that they wanted, a new digital camera. Because of this I have decided to brush up on how to use it to more of its potential. So let’s talk about manual camera operation.
You have a new camera that, unlike your phone’s camera, was designed exclusively for making photos. I am going to assume that the reason that you wanted your new camera was to make photos that are even better than you could with your cell phone. To do this you will need to move away from the point and shoot mindset and decide to be the computer that controls the camera instead. Switch to Manual Mode.
Let’s start with the “Big 3”. Exposure time - Aperture Setting - ISO/Film Speed. When you’re taking a photo you will want to understand what all three are, how to control them and how they affect each other.
Shutter Speed - Your shutter is a gate that opens and closes to allow light from the outside to come inside of the camera and fall on the film/image sensor. The longer your shutter speed is the more light that’s allowed in and, conversely, how much can be stopped or blocked from coming inside. Consequences of both being a twofold. The first is the exposure of the image, or how bright or dark that it is. The second being the allowance or elimination of movement in your photo. The primary concern typically is to get a photo that’s bright enough without movement being blurred, but there are times when you will want to show movement or blur in your photo such as a waterfall. A fast shutter speed freezes movement while a slower one will blur movement.
Aperture setting - The aperture is a mechanism in the lens that you can adjust to vary the size of the hole that the light goes through as it passes through the lens and into the camera. The larger the hole the more light that can come through in a set amount of time (shutter speed). You can have the same shutter speed but control the amount of light with the aperture. The second consideration when adjusting your aperture is how it affects the depth of field, or how deep the focus is in the photo. When you choose a larger hole, which is represented by a smaller f/stop number, it will give you a smaller or shallow depth of focus, whereas a smaller hole with a larger f/stop number, will give you a larger or deeper depth of focus. One will realize that with a smaller hole for the light to come through a longer shutter speed will be needed to get the same light inside. With a longer shutter speed you will have a chance to blur, as mentioned previously, which will require you to use the third setting in our big three adjustments to further affect the exposure.
The third and last adjustment that we will add to the formula is what was once called “film speed” in film photography, which is indicated by the ASA rating of the film, whereas in digital photography, where there is no film, we adjust the ISO. The film speed indicated how sensitive to light the film is. A lower rating such as 400 ASA will be less sensitive to light than a film rated at 1000 ASA. When the film is more sensitive to light it takes less light to expose the film so you can use the film in darker light or it will allow you to use a faster shutter speed or a smaller aperture opening. With this understanding we can translate the application of this information to digital cameras easily. In digital cameras the film is the image sensor and the film speed is translated to the ISO setting of the camera. The ISO setting varies the sensitivity to light of the image sensor. The beauty of shooting with a digital single lens reflex camera is that you can vary the light sensitivity of the camera using a dial, whereas in film you had to change the whole roll of film. The one consideration when setting the ISO is that the higher the ISO the more grain/noise that you will have in your image.
Let’s summarize what has been covered. You have three settings, shutter speed, aperture opening, and ISO or light sensitivity. All three will affect the each other so you will usually need to adjust another, or both, when one is changed. We can now use this knowledge to set our exposure considering movement, depth of focus and acceptable image noise.
Next, to know how close your exposure is to proper your digital SLR camera comes with a built in light meter. As you set your camera you can keep an eye on the light meter and balance it in the center. Once you have your shutter speed, aperture and your ISO set according to your light meter take your shot.
Once you take your photo you will have a display on the back that will show you a preview of the image. You can check your focus and your composition with this preview of the photo, but you can’t get a real indication of the exposure therefore, the next and last step is to check the exposure with the histogram. The histogram is a graphical representation of the range of light that was captured in your photo. If the histogram doesn’t show automatically with the preview you can find a setting that will allow it. The histogram will look like a rectangular box with a bar chart inside. The left side will be the dark part of your photo such as shadows while the right side will represent the highlights. What you will want to attempt is to balance the highlights and the darks with your “Big 3” adjustments using your histogram as your way of verifying your success. If the settings were a little off, make an adjustment and take another photo. Film is cheap when you’re shooting digital.
All of this may sound a bit confusing at first but the confusion leaves with practice. Like I mentioned previously film is cheap when you’re shooting with a digital camera so go out and take a lot of photos. Therein lies the secret to improving your photography. Practice and experimentation.
It’s my hope for you that your new camera, or your old one for that matter, will provide you with as much fun and life enriching experiences that mine has for me.
Happy New Year.