The ultra-short photography course (or – Learn how to take better pictures in 10 minutes)

There are many things one can do to take better pictures, but I’d like to dedicate this post to the very basics of using the camera. Got 10 minutes? Here we go:

First, you need to know that no matter how expensive or sophisticated your camera is, Essentially it is not more than a dark box with a hole on one end that lets the light in (the lens), and a light-sensitive material on the other end that captures that incoming light (the sensor in a digital camera or the film in a film-camera). Everything else is gadgetry.

A camera needs light to take a picture. The light reaches the sensor by passing through the lens, but the light’s path is normally blocked by two barriers:

1. The aperture
2. The shutter

The aperture is a hole whose diameter can be changed (i.e. it can be opened or closed). The opening of the aperture is experessed by an “f-number” – the lower the number, the more open the aperture is, and vice versa. The aperture is normally located within the lens, and it stays fully open until the shutter release button is pressed, at which time it automatically closes down to its predetermined value.

The shutter, on the other hand, is like a curtain that has only two states – it’s either fully closed or it’s fully open. Clicking the shutter release button opens the shutter, and it remains open for as long as you want it to (from fractions of a second to seconds or minutes). The shutter is normally located within the body of the camera, just in front of the light-sensitive sensor.

So, so reiterate – when the shutter release button is clicked, two things happen:

1. The aperture is set to the correct opening.
2. The shutter opens and reveals the sensor to the light that is incoming through the lens.

Thus, in low-light conditions, in order to allow a sufficient amount of light to reach the sensor, you’d want the aperture to be as open as possible, and you’d want to the shutter speed to be low (i.e. allow more time between the time that it opens up and the time it closes down);  In conditions where the light is bright (outdoor on a sunny day), on the other hand, you’d want to close the aperture and use a high shutter speed (so that less light reaches the sensor).

We can think of the “perfect exposure” as a glass of water that needs to be filled up exactly. To do so we can either open the tap to the maximum and allow the water to run for a very short time, or we could open the tap to only a trickle, but leave it running for a longer time.

Many cameras, including some point-and-shoot ones, have two very useful semi-automatic modes – “Aperture priority” and “Shutter priority”.

Aperture priority means that you adjust the opening of the aperture, and the camera adjusts the shutter speed automatically. That’s like saying that you determine how much to open the tap, and the tap itself will determine how much time the water should be running before the glass is filled.

Shutter priority means that you adjust the shutter speed (i.e. how long it remains open when the button is clicked), and the camera adjusts the aperture automatically. That’s like saying that you determine how long the tap will remain open, and the tap automatically determines to what degree the tap should be opened (i.e. the flow) to get the glass filled up.

Now comes the interesting part – both the aperture and the shutter have a secondary role (the primary role being to control the amount of light that reaches the sensor). That secondary role is what gives us the opportunity to get creative and take some really great pictures. Here are these roles:

• The aperture controls the depth of field.
• The shutter controls the sharpness of moving objects.

Let’s talk a little on both of these:

• Aperture = Depth of Field (DOF)
  When you focus the camera on something (assuming neither the camera nor your object are moving), that object would always be sharp, and so will be everything else that is in the same distance from the camera as that object. However, things that are in front of the object or behind it may be sharp or blurred, depending on how open or closed the aperture is. The more you open the aperture (i.e. the lower the f-number), the more blurred  will become the objects that are in front and behind your subject. And vice versa – the more you close the aperture (i.e. use a higher f-number), the sharper everything would look in front of your subject and behind it.
  Let’s make an experiment: take your camera and point it to an object that is about 2 meters from the camera. Take two pictures of that object – one with the aperture open to the max and one with the aperture closed to the max. Compare the two pictures, and try to see the difference in the sharpness of the foreground and background. Note that the object itself is sharp on both pictures.
  *It’s best to put the camera on a tripod, to eliminate any blur that can result from camera shake.
   
• Shutter = sharpness of moving objects
  When using a fast shutter speed (e.g. 1/2000 of a second), the shutter opens very briefly, exposes the sensor to the incoming light, and closes immediately. This will “freeze” the subject, even if it is in motion.
  When using a slow shutter speed, on the other hand, the shutter remains open for a longer period of time. During all that time, the light keeps coming in through the lens, so if either the camera or the subject move, there will be a smearing effect, creating blur. The slower the shutter speed and the faster the movement (of the camera or the subject), the higher the likelihood of blur.
  Try this:  put your camera on a tripod or on a steady surface, and shoot another person who stands still. Use a shutter speed of ~1/30 of a second or slower. Next, shoot the same person, only now ask him to move quickly during the shot. You’ll see that in the first picture your subject is sharp, while in the second he/she is blurred/smeared.

Let’s summarize:

• The aperture controls the amount of light that reaches the sensor, but it also controls the depth of field. Close the aperture (set it to a large f-number, such as f22) and you’ll get more sharpness of objects that are in front and behind the subject; open the aperture (set it to a small f-number, such as f2.8) and you’ll get less sharpness of objects that are in front and behind the subject.
    
• The shutter controls the time during which light from the lens is allowed to reach the sensor, but it also controls the sharpness of moving objects. Use a high shutter speed (such as 1/1000 of a second) and you’ll get everything sharp (“frozen”); Use a slow shutter speed (e.g. 1/15 of a second) and moving objects will appear blurred.

What is the practical use of all of this?

When you take pictures of people (portraits), you’re likely to want to put your subject in focus, but blur the background by using a wide open aperture. This produces very pleasing results and guarantees that the background won’t be a distraction (as it would be if it were as sharp as your subject). Here’s an example of a portrait with blurred background:

In contrast, when you take a picture of a scenery, you’d often want to get everything sharp, near as well as far, by using a relatively closed aperture.

Similarly, if you’re shooting a sports event and you want to get everything sharp, you’d go for the fastest shutter speed possible (depending on your camera’s capabilities and the brightness of the scene). On the other hand, if you’re shooting a dance performance and you want to accentuate the movement and add some drama, you’d want to consider using a slow shutter speed to create an intentional motion blur.

So, if you’re shooting a relatively static subject and you’re mostly interested in controlling the depth of field, set your camera to aperture-priority mode (usually denoted by an “A” on the mode dial), choose the smallest f-number, and let the camera adjust the shutter speed accordingly. If, on the other hand, you’re shooting a moving subject (e.g. a sports event), and all you care about is to get everything sharp, set your camera to shutter-priority mode (usually denoted by an “S” on the mode dial), choose a high shutter speed, and let the camera adjust the aperture accordingly.

Did you find this tutorial helpful? Please drop me a note and let me know.

P.S: I know.. if you managed to read it all the way through, it didn’t really take 10 minutes, did it?..  :-(

The most important photography tip ever!

Sometimes, when I get tired of taking pictures, I would give my camera to a friend and ask them to take some pictures of me, for a change. When I then look on the PC at the photos my friends took, I often see the same thing:  the person in the photo is completely blurred, while the background is sharp.

Why does it happen? My camera is set to focus on a point, which is in the center of the frame. When the subject of the photo is in the center, the camera would get the focus right. However, when the subject is off-center, or when there is more than a single subject (like two people standing side by side), the camera would focus on what’s exactly in the middle of the frame, which, in this case, would be the background.

So, the most basic rule when taking pictures is this:  First, choose the subject you want to be in focus (i.e. sharp). Then, move the camera so that this subject is in the center of the frame. Now click the shutter release button hafway down, so that the camera focuses on the subject but does not yet take the picture. Now hold the button half-pressed and move the camera so that the subject’s position within the frame is where you want it to be. Now click the button all the way down.  Or, in short – point to the subject and half-click to focus (keep the button half-pressed) –> recompose your shot –> click to take the picture.

Tips for shooting in low-light conditions

Most cameras, especially the point-and-shoot ones, perform miserably in low-light conditions (e.g indoors) when they cannot use the flash. When I was recently asked how to take better photos in low-light situations with no flash, I’ve decided to first explain a little about the basics of exposure, and then suggest possible solutions.

First, you need to know that for every scene there is a certain amount of light that needs to reach the sensor (the electronic part in the camera that is the equivalent of a film) to create “the perfect exposure”. When the amount of light that reaches the sensor is lower than that optimal amount you’ll get an under-exposed photo (i.e. too dark), and when the amount of light is higher you’ll get an over-exposed photo (i.e. too bright).

Good exposure

Too dark (under-exposure)

Too bright (over-exposure)

The amount of light that reaches the sensor is a function of 3 things:

1. The shutter speed
2. The size of the aperture (known as the “f-number”)
3. The sensitivity of the sensor (ISO)

Thus, when you’re inside a dimly lit place and you cannot use a flash, you’ll want to do any or all of the following:

1. Use a slow shutter speed (because the longer the shutter is open, the more light will reach the sensor).
2. Open the aperture to the max (i.e. use the lowest possible f-number).
3. Increase the sensitivity of the sensor to the max (i.e. set the camera to the highest ISO number that it supports).

Now here’s the thing – both the aperture and the ISO sensitivity are limited. They both have a maximum, and once it is reached there’s nothing more you can do. The shutter speed, however, is practically unlimited – you can set it to open as fast as 1/2000 of a second, or you can leave it open for minutes or even hours (remember that the longer the shutter remains open, the more light will reach the sensor).

The problem is that low shutter speeds are very sensitive to motion. If the speed drops below ~1/60 of a second (this varies with different parameters) every little camera shake is likely to result in a blurry photo, even if your subject is motionless. If your subject is in motion, you’ll need an even faster shutter speed to “freeze” the movement and get a sharp picture.

So, what can you do? Here are some practical suggestions:

1) Set the camera to “Aperture-priority” mode. Most cameras have it, and it is denoted by an “A” on the mode dial (or wherever it is on your camera). Once you’re in “A” mode, set your aperture to the lowest f-number possible. The camera will adjust the shutter speed accordingly so you won’t have to worry about it.

2. Set the ISO number to its highest possible value (i.e. ISO 800, ISO 1600, etc). Take into account that there’s a price to pay for doing this – the higher the ISO number, the more “noise” (graininess) you’ll have in the picture!

3. Try to get as close to your subject as possible, so that you don’t have to use the zoom. Using the zoom reduces the amount of light that reaches the sensor even more, and also forces the camera to use a tighter aperture (i.e. it automatically raises the f-number).

4. If you’re planning to buy a new camera, you’ll want one with a larger sensor (the larger the sensor, the more light it “collects”, and the less noise you get when you set the sensitivity to a high ISO number). The problem is that the bigger the sensor, the bigger (and more expensive) is the camera. Still, if size and price are not your primary considerations, you’ll definitely want to get a dSLR (digital SLR). An example of an entry-level dSLR is the Canon Digital Rebel XTi or the Nikon D80.

5. You can sometimes use a technique called “panning” to shoot a moving subject. It means that you follow your subject with the camera, and press the shutter release button while continuing to move (pan) the camera in the direction of your subject’s movement. It works only when your subject is moving in a straight line that is perpendicular to the camera, so it’s not very useful, but if it succeeds it can produce some beautiful results.

6. Use a tripod. It won’t help if your subject is moving, but it would prevent camera shake.

7. Finally, and perhaps most important, it’s not always desirable to use the fastest shutter speed possible and freeze your subject’s movement. Such photos often lack a sense of movement and might be boring. Some degree of motion blur can actually be beautiful – it accentuates the movement and adds drama.

Good luck, and I hope this helps.