Back To Basics
An in-depth introduction to DSLR photography
By Connor Archard
I am writing this guide in concert with Roman in an effort to help out amateur photographers who are looking to switch off of automatic shooting modes and into manual. A word of warning this is not something to master overnight. There is a lot to learn, and there is a long road ahead of you. But trust me, it does pay off.
This guide to manual photography – if it ever comes to fruition – will start off by covering the basic points of exposure, white balance, and focusing in detail. A glossary will hopefully make its way into the guide somewhere, and hopefully this will help at least one person and all of our time will not have been wasted. Without further delay, let us begin!
The Three Pillars of Exposure
Exposure is the aspect of a picture’s lighting. The amount of light that gets into your camera and shows up on your picture is determined by the three pillars of exposure that we will be going over: Shutter speed, ISO speed, and F-Stop. In layman’s terms, we will be going over how to control how light or dark a picture is in this section.
NOTE: The trick of correctly exposing a picture lies within using shutter speeds, ISO, and F-Stop values in concert and at the appropriate times. All three are equally important. Neglecting any one will ruin the lighting of a picture.
I. – Shutter Speed
Starting with the basics; shutter speed is the length of time that the shutter on your camera is open. A picture is developed by the processor in the back of the camera (right behind the LCD screen), and will create the picture by having light bounced off of it. This means that light needs to get inside your lens and all the way to the back of your camera to make a picture. This doesn’t mean you need to point your camera right into lights all the time. It just means that whatever you’re shooting at needs to have at least some light on it (which will then be reflected into the camera).
Now that we know the end goal of exposure (getting the right amount of light to the processor in the back of your camera), we can talk about getting it there. The camera has a shutter in it that opens and closes at an interval determined by the camera’s manual settings. This interval can be changed by spinning that ridged wheel on the back face of the camera.
The squared off number is actually the amount of time that the camera’s shutter is open. That means that in this case, the shutter is open for exactly 1/80th of a second. Don’t think of this value as being two separate numbers; acknowledge the fact that it is indeed a fraction. The larger the denominator is, (bottom number) the shorter the exposure time. Just think of it this way: 1/80th of a second is a lot longer than 1/200th of a second. By the same logic 1/15th is a lot longer than 1/80th. If you see a whole number instead of a fraction that means that your shutter will be open for a matter of seconds (for example 1.3”). This is something you want to reserve for night photography.
It will most likely take you a while to get a feel for how long different lightings will need to be exposed for (a.k.a. – what shutter speeds to use when), but here are some general guidelines…
1. Unless you are using a tripod NEVER shoot above 1/60th of a second (above here meaning longer than or at a value of 1/59th or 1/15th or 1” or anything of that nature. Got it?) If you shoot above 1/60th hand-held, the shake from your hands will cause the picture to blur and the shot will be ruined by motion.
Note the difference in clarity and definition.
2. Shooting below 1/250th (a value of 1/251st or 1/320th etc…) will most likely freeze all motion in an image. That is to say, even if a car is flying by you really quickly as you take the picture, it will be still and crisp in the processor.
II. – ISO Speed
ISO is a digital boosting of light values done by your camera’s processor. This means that although ISO values increase light by the same amount no matter what camera you use, each camera’s picture quality will respond differently. The trade of between high ISO values is being able to shoot in low lights at acceptable shutter speeds (Remember, 1/60th and below!!) and digital noise. Pure noise is that fuzzy white buzzing stuff that comes on your TV when the channels mess up. High ISO values start to bring this noise onto your pictures and it ruins the quality and appearance of most images.
This is where your exact DSLR model comes into play… higher end models will be able to reduce the amount of noise at higher ISO values, which lets you shoot with high ISO freely. Entry level DSLR’s are a different story and vary across the board.
[Roman] – While Connor has all of the correct information about ISO, I don’t agree with the paragraph above this quote. Higher end cameras don’t always tend to have better noise reduction. Higher end cameras just make it seem as if there is less noise because they have a larger image sensor, a device that converts the optical image received through the lens into an electrical signal. If you view any of the example pictures he gives below at full size, you will notice the noise is really just the same throughout, but because the D300 has a larger sensor, the noise is less apparent at non 100% zoomed views. I wanted to make sure I pointed this out, because it is never about the camera. It is how you, as the user, know how to manipulate your particular camera to get the results you want. High ISO is something that you should always try to avoid. A flash, or other forms of lighting will always be a more sensible choice than to just boost ISO right away. I will post a picture taken from my entry-level Canon Rebel XS to consolidate these ideas. I can not use the same subject as Connor, but please notice the varying levels of noise in the different ares of light.
One last note before I end my insert. ISO visibly tends to affect only the darker areas of your pictures. Look at the picture above one last time and notice the transition zones between the light and dark areas, and notice the noise become more and more apparent as you go from light to dark. That is the end of my insert. [Roman]
I will give you the final gist of ISO and then leave you with some examples. The higher the ISO, the lighter your picture. The higher the ISO, the more noise in your picture. The opposite is true for lower ISO. The squared off value above is the ISO, and it can be changed in different ways on different cameras. Look in your manual or experiment to figure out how to change yours.
Examples – ISO is labeled. Shutter speed was changed to keep a consistent amount of lighting and detail
Camera – Nikon D60
Notice how there are dead pixels and a lot of noise in the higher ISO ranges, but that I could expose the picture with ease. To tell the truth, I broke my own rule and shot above 1/60th handheld on the last one because that was the only way to get the picture to have any detail. This just goes to show that ISO is a big factor in exposing your pictures.
Camera – Nikon D300s
Notice how there is less noise at the same ISO levels. This is because the D300s has a more advanced processor than the D60 and can reduce the digital noise as it takes the pictures.
While taking pictures, think about how your own camera handles noise and set limits for yourself. For example, I know that when I’m using my D60 I try to keep at ISO 400 or lower because ISO 800 is pushing it a bit too much for me. However, on my D300s I can shoot at ISO 1600 comfortably.
Notes about noise:
Noise can cause a degradation of detail of image quality. This comes in the form of general fuzziness in dark areas, or if you are shooting in JPEG modes in your camera (as opposed to raw) dead pixels. Dead pixels are pixels that are out of place. A dead pixel for example is a bright read square in the middle of some blue area. Dead pixels are normally the wrong color for their surroundings and are the result of your camera failing to boost the colors and brightness of a very specific area.
III. – Aperture Value / F-Stop
The aperture value, or F-stop, is a number that defines how wide your lens is open. To understand how this works, think about water coming through a hole in a boat; the larger the hole, the more water. The same is true about light coming through the lens of your camera. As we have already stated, the goal of exposing a picture correctly is to get just the right amount of light onto the processor at the back of the camera, so the F-stop is very important.
Now, into the details. F-stop is denoted on your camera by the letter F followed by a number (the squared off thing above). The smaller the number, the larger the lens opens up. The larger the number, the smaller your lens opens up. Think of the number as defining how much light is blocked, or how much material your lens is putting up to block light. This means that the lower your F-stop is, the more light gets into your picture meaning you can use shorter exposure times and lower ISO speeds.
Let’s review – small number = large hole large number = small hole
Here are some example pictures taken of an old film camera (the Argus Anastigmat AF c.1937) I am looking into the lens of the camera to try and show you the difference in F values. I changed the colors so the wall behind the camera would really stand out; the orange hole in the lens is the wall behind, look to see how wide open the lens is
Reference point to show you what you are looking at
One more thing… Aperture values are tricky because they not only determine how much light gets into the camera, but they also affect the depth of field. The depth of field is the part of the picture that is in focus. Cameras focus on a plane parallel to the face of the processor. The plane will be the only thing in focus, and the depth of the plane is determined by the focal distance and the F-stop. The main issue is the distance between the camera and the subject being focused on (the closer the subject the shallower the depth of field), but the F-stop also plays a huge role. The smaller the f-stop, the smaller the focal plane (shallower depth of field) the larger the f-stop, the larger the focal plane. This means there is trade off between depth of field and exposure of your picture. This is a tough concept to grasp because it is rather abstract, so I recommend you go out and experiment with it.
Aperture value endnote: different apertures have different picture qualities. Most lenses have the highest quality around F8, and quality starts to drop off after F16-F22. Try to avoid extremely high F-stops if possible.
THIS IS JUST A START. PLEASE EMAIL ME WITH ANY QUESTIONS, COMMENTS, OR CONCERNS. MAYBE EVEN REQUESTS FOR OTHER GUIDES IF YOU LIKED THIS ONE. I KNOW THIS ISN’T PERFECT, BUT COME ON. IT’S 2AM