Where to begin? Hopefully you’ve stumbled across this guide wanting to know what is involved with becoming a digital photographer. Obviously, there is more knowledge about the field than you could probably every dream of trying to divulge. We’re going to take a stab at it anyway. By the end of this guide you should go from knowing absolutely nothing about cameras to a full head of knowledge that will allow you to head out into the world and start taking photographs. There’s really no “correct” starting point in photography so we’re just going to dive headfirst into the world of cameras and how to take photographs.
Camera
If you’re serious about photography you’re going to need something better than the small pocket camera that you use when on vacation. You’ll probably need to spend a few hundred dollars on the right type of equipment. That includes a camera, straps, bags, tripods, etc. For now though, let’s just focus on the camera. What kind should you buy? Preferably you should pick up a DSLR camera, or Digital Single-Lens Reflex camera. Why? Because these days DSLRs are the industry standard and compared to film cameras, they’re able to hold a lot more information and obtain a purer image. Because of the mechanical operations inside of digital cameras, the image that is seen through the lens is a much more accurate representation just milliseconds before a photo is snapped compared to a standard film camera. Also, the base of the camera and the lens are two separate pieces and can be interchanged. This makes for better versatility in the field. Being able to swap out lenses on your camera (we’ll get to why you would ever want to fairly soon) is a great feature that shouldn’t be overlooked.
Some popular names in the camera world are Canon and Nikon. While very disputable, the Canon Rebel XT and the Nikon D70 and D90 are the most popular on the market.
Focal Length
Before we talk about the hardware side of things when it comes to lenses, it may be best to first discuss the focal length of a lens. Cameras have lenses on them to focus incoming light and direct it towards the film. In the case of a DSLR, there is no film. Instead there is an image sensor at the back of the camera that the lens directs the light towards. Typically the size of this sensor will be 35mm in length. You have probably heard the term “35mm film” when talking about cameras in the past. This simply means that the sensor at the back of the lens is 35mm wide.
When you put a lens on the front of the camera, the lens restricts the amount of light that can reach the sensor. In theory, without any lens, all of the light that is in front of the camera would reach the sensor. But because the light isn’t focused, all of your images would end up as blurry white splotches of garbage. You may or may not have seen someone in the past with a really long lens on the front of their camera or a “regular” looking one that seems to just be a few inches in length. Both lenses serve different purposes. But how?
The amount of information that makes it to the sensor at the back of the camera is determined by how much light the lens can focus. Focal length in a camera can be best described as the amount of information that makes it to the sensor relative to the distance the subject is away from the lens. What I mean by this is if you have a very long lens, the viewing angle for the photograph will be much narrower because light from the far left field of view and far right field of view can’t make it to the sensor. So in summary, if you have a very long focal length, i.e. your subject is very far away and you are focused on them, you will have a narrower field of view. If your subject is very close to the lens, the focal length is much smaller and you will have a much wider view of the area surrounding the subject. In this diagram the focal plane is where your camera is and the focal length is how far away the subject is. Different lenses have different focal lengths meaning they have an easier or harder time focusing on objects at closer/farther distances.
Light Exposure
I’m not quite sure how to go about this section and how to explain how light works. I’ll do my best to explain why we see things the way we do, just so you have an idea of the reason things are named the way they are in terms of exposure and how it all comes together to give you a picture.
We’ll start things off with a little biology and psychology. The human eye is a very funny thing in that it has a very difficult time distinguishing how bright something is. To the human eye, when the amount of light from a light bulb for instance, is doubled, the eye sees this increase to be the exact same increase as when the newly doubled light is doubled yet again. That means that the eye is only capable of understanding the increment of change between brightness, not the actual amount of doubling taking place. Asking someone to figure out when a light has doubled is next to impossible because the eye is simply not well equipped enough to do that.
Moving on the camera terminology, light is measured in what are called “stops.” One stop represents the increment between one doubling and the next. Stops do not represent the overall brightness of objects but rather, relate their brightnesses to one another. One light bulb at a particular brightness and another light bulb of double the brightness would be considered to be one stop apart. While the first light bulb may be next to blindingly bright and the second one even brighter still, the second one is still one stop (double the brightness) of the first. Hopefully you can see that brightness in terms of “stops” is nothing more than a measure of how bright they are compared to one another, not how bright they are in terms of light measurement.
The amount of light that makes it to the sensor at the back of the camera is controlled by many different things, two of the most important of which are aperture and shutter speed.
Aperture
On the camera itself there are many different settings for aperture. They normally come in the form of odd looking decimals that don’t really seem to be of use to anyone. But, they are indeed logical numbers. Cameras let light in through an iris. To control the amount of light that makes it to the sensor, a small opening is opened and closed on top of the iris called an aperture. Aperture numbers are measured in terms of a ratio of the focal length (the focal point within the lens), and its width. In a camera that has a 35mm focal length and width of 35mm, the optimum aperture size is 1 because the ratio of 35 to 35 is 1. That probably all sounds confusing, because it is. It takes a lot of practice to understand how to open and close the aperture to make things brighter or darker.
To halve the amount of light that makes it into the iris, the aperture has to be halved as well. Due to the length of lenses relative to the length of the sensor at the back of the camera, camera stops (aperture settings), multiplying your current aperture setting by 1.4 will give you a smaller aperture size and consequently, half the amount of light. The number 1.4 is based on dividing the circumference of the aperture circle surrounding the lens by two. As you move up the aperture scale settings (1,1.4,2,2.8 etc..), the less light that is let in. Bigger the number, the smaller the amount of light that gets in. Moving all the way down to an aperture setting of 1 is often referred to as “wide open” meaning that all of the light from the scene is making its way into the lens. In places where there is often too much light, an object might be called “hot” meaning that it is too bright and aperture stops will have to be increased to reduce the amount of light that makes it into the sensor.
Shutter Speed
Now that you understand that you can control the amount of light that enters a camera by changing the size of the aperture circle around the iris, there’s yet another step to take to control how much light enters.
The shutter on the front of the camera is a flap that opens and closes for small increments of time to allow light in. because the iris is extremely sensitive to any type of light, a barrier must stand in the way between it and the outside world. When you press the button on the camera, the shutter flies open and lets light flood the iris and make its way to the sensor. Because there is limited space on the sensor for light to be absorbed, the shutter has to be very precise in how long it is open for. Think of it like paint. If you had a blank canvas (your sensor) and started throwing paint at the canvas from a distance, after a relatively short amount of time you’d have specks of paint all over the canvas. If you kept throwing paint (meaning that the shutter is left open) eventually the paint would start overlapping the previous paint and make a mess of the picture. That is exactly what happens if the shutter is left open too long on a camera. Too much light floods the sensor and things become a blur.
Through some pretty fantastic engineering, camera developers figured out exactly how long a shutter should be open to capture an image. Why do images look still when you take a picture? When the shutter is opened to let light in, the amount of time it stays open is the amount of time that elapses in the scene. So as light is emitted from your subject’s body, it makes its way to the sensor of the camera. Hypothetically speaking, if the subject was to emit light from one part of the scene one split second and then emit another bit of light from a completely opposite part of the scene, the subject would appear twice in the same photo assuming the shutter was left open long enough for the light from point A and point B to reach the camera.
In summary, if you set a very quick shutter speed, something like 1/1000th of a second, you will be able to capture very sharp images that took place on that interval. If you leave the shutter open for more than a few seconds, images become blurry and unmanageable because of the amount of light information that made it to the sensor. Sometimes though, in dimly lit scenes, the shutter speed has to be set higher to capture more light from the same objects, making them seem brighter than they actually are.
Meter
Most modern DSLR cameras are capable of determining the perfect exposure for a shot. They are able to see what you see through the lens and automatically set the aperture and shutter speed on the camera to capture the image as it is seen. In some cases though, the camera is doing nothing more than guess work. Because it has no brain like you or I, it can’t know for sure that you’re not pointing at the field of grass in the background as opposed to the flower right in front of you. Because of this, it is often unsure how black or white a picture needs to be relative to how it looks in real life. This is because when it picks the aperture and shutter settings, it sets them for what it thinks you’re looking at and ultimately causes other objects in the shot to be over or underexposed. To counter this there is a technique called metering which gives you the option to point the camera at an object and tell the camera how white or dark it should be.
Things like stones look gray but if the camera is set to take a picture with a very high aperture setting, the stone may come out black. Settings on the meter range from -2 to +2. These numbers represent the number of stops above or below zero (the current light setting), it should go. If you wanted to make the stone look even darker than it currently does in the shots, you would put the meter setting on -2 to reduce the light content by even more and if you wanted it to look brighter, towards a whiter or gray scale, you would of course set the meter to +2.
Sensitivity
The last concept we’re going to cover is sensitivity on a camera’s sensor. A camera’s plate sensitivity is measured in terms of ISO units. Why would you ever want to change the sensitivity of the plate sensor? A number of different reasons actually. Say you have your camera set up perfectly to take a photo on a very bright day. Because the outside light is very bright and your shutter speed is probably set to a very low setting to prevent a lot of light from getting in, you need to set up the camera’s sensor to be less sensitive to the light coming in as well. By reducing the amount of light that makes it to the plate through the aperture setting, you also reduce the amount of information coming from the scene. You can counter this with the sensitivity setting.
You may be asking yourself now though, if the shot has the potential of being too bright, why wouldn’t you just reduce the aperture or shutter speed? Well the shutter speed is set to capture the timing of an image. So in rain fall for instance, if you want to capture a single rain drop mid flight, you can’t readjust your quick shutter speed to accommodate the brightness and your aperture settings are there in such a way to make things in the foreground or background seem to be in better or worse focus. The last thing left to change is the sensitivity.
Sensitivity settings on a camera range from 100 to about 10,000. There are a few cameras that go well above that range but without some money to burn, you probably won’t be able to afford them. The higher the sensitivity number, the less sensitive the plate is. Sensitivity settings work the way as the eye meaning that if you want an image to be twice the stop brightness, you would double the ISO number. If you want 2 stops brighter, 400. 3 stops brighter, 800…etc.
Increasing the sensitivity also increases what’s called noise. This is unwanted information reaching the plate causing a distortion. Whenever possible it is best to have the plate be set to its stock settings so just the right amount of light hits. In certain situations though, the plate sensitivity has to be increased to accommodate for the lack of or overabundance of light. But as the sensitivity increases, so does the amount of “noise.” Noise can be thought of as static like what would appear on a TV set.
Editing
Wow! We made it through everything that there is to know on your first DSLR camera. Of course, there’s no substitute for practice and fiddling around with different settings and seeing the results. Pictures and descriptions can only show so much. But now that you have some nice photos, or maybe even some not so nice ones, it’s time to edit them.
Editing is a whole other animal that would more than likely take another entire article all by itself. But, to get you started in the right direction you will want to check out programs like GIMP (free) and Adobe Photoshop for your editing needs. Both programs offer a lot of tools to make your photos brighter/darker and better balanced. Sometimes photos just don’t come out the way you want them to in the real world and a little tweaking is necessary. Have fun with it and go wild. This is just the beginning!
That’s it from our end for now. If you have anything you would like to add, feel free to do so in the comments section.
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Awesome article.. Helped me a lot in understanding the basics. Thanks
Hello
I am just a beginner in photography.You have described very well about a digital photography.Its really easy to understand about shutter speed,meter,sensitivity and editing from this post.Thank you very much for this helpful post.