All cameras from the simplest to the highest of high tech share some basic features.
Lens. The lens is made up of layers of glass which are each shaped to focus incoming light onto a surface used to expose the image.
Light sensitive medium. In digital cameras this is a sensor – which comes in a variety of types but all basically change light into an electrical signal. In film cameras, the exposure takes place on, you guessed it, film.
A variably sized hole call the aperture. Located in the lens, the aperture control is a series of blades which changes the amount of light passing through lens. The aperture’s basic unit of measurement for how much light is getting through is the “ƒ Stop.” A whole Stop change in aperture lets in either half as much light or twice as much light. On your lens (or in the view finder, or maybe on an LCD menu on your camera) you typically see numbers like ƒ1.8, ƒ2.8, ƒ4, ƒ5.6, ƒ8, ƒ11, ƒ16, and ƒ22. These are whole Stops which, as previously explained, lets in twice as much or half as much light compared to the Stop beside it.
(It should be noted, f1.8 is actually 1/3 of a stop more than f2 which is the actual full stop difference from f2.8 – however more lenes go to f1.8 than f2 as the maximum aperture.)
A shutter which limits how much time light is allowed to enter your light-tight box. The measurement for the shutter is the “shutter speed,” also known as Stops, which is measured in fractions of a second like 1/30th, 1/60th, 1/125th, 1/250th, 1/500th and so on. You can see a little easier how each might vary the exposure by either half as much light, or twice as much. Exposure times can also vary from 1/8000th of a second to several seconds. Some systems can use up to hours of exposure
When hand holding the camera, its important to make sure the shot is not blurry from camera shake. You should have the shutter set to the “same number” as you lens length. For example, if using a 50mm lens, you want a shutter speed of at least 1/60th of a second. If you’re using a 135mm lens, 1/125th is okay, but 1/250th would be better. I’ve found with digital, because most have a multiplier effect (the sensor is smaller than 35mm film, and effectively make the lens 50 per cent longer) you need to set the shutter accordingly. If using a 50mm lens on a digital SLR, I set the shutter to the half stop of 1/90th or faster.
If you don’t have enough light for the exposure I recommend a sturdy tripod. If you have a questionable speed, you can try bracing yourself against a post, tree, or other stationary object. I never stop from taking the shot even when I’m doubtful, you never know – you might get a great shot anyways.
Light Sensitivity also known as ISO – The actual written standard for ‘measurement of sensitivity to light’ is ISO 5800:2001 (in case you wanted to know.)
One of the ways to think about light sensitivity is that if – in bright daylight with the sun behind you – you set your aperture to f16 you can set both your ISO and shutter speed to ‘about’ 100 (actually 1/100th of a second for the shutter.) And if you set the camera to ISO 400 you can use 1/400 of a second. With old film cameras you had to go to the nearest similar shutter speed – 1/125 and 1/500 in this example. These settings will give you a very close to proper exposure.
Low ISO gives you the best quality in terms of noise or graininess, and that high ISO gives you more latitude for higher shutter speeds. It’s a compromise. With experience and practice you get to know which way and how much you can push either of those settings.
A light tight box. Holding the lens, shutter and exposure medium, the body of the camera keeps light out. On most cameras, the body also holds electronics to control the aperture and shutter.
The meter will help you determine the exposure you need. This is not something you can use on all cameras – particularly very old SLR’s and most point-and-shoot style cameras. The meter may be part of the camera’s system, but not have any visible meter for the photographer to use. However, most serious cameras do have a display for the meter so you can determine your exposure.
The most important part of the camera is the six inches BEHIND the viewfinder (assuming you use the viewfinder, if you normally look at the LCD on the back of your digital camera that would change to about 18 inches.)
A note about Stops. On modern cameras, there are numbers for additional fractions of a Stop, which can be either 1/2 Stops or 1/3rd Stops. This makes learning your stops a little more complicated but the principal still works.
Almost everything else on modern cameras is a way to control the focus of the lens, the aperture or the shutter speed. On digital cameras there is one last control which is to set the colour temperature. This will be explained later in another lesson.
If you’re using a modern digital SLR, or a film SLR with a lot of automation on it, I highly recommend you read your camera’s manual closely to find out how to do basic control of: setting the camera to manual exposure, setting the lens aperture, and setting the shutter speed. These three areas are important for getting the most out of these lessons.
If you are using a pocket camera or point-and-shoot style camera, you can set these features on some but not all cameras of this type. If not, you can skip the exposure control lessons and just do the composition lessons.
METERS AND LIGHT
Getting a good exposure generally depends on understanding light and using a meter to measure the light in a scene.
Reflected light and incident light meters
Metering reflected light is exactly what it sounds like – you’re measuring the light bouncing off of the subject. Incident light is measuring the hitting the subject (before it bounces back to the camera.)
A meter helps to determine both the aperture and shutter speed. In some cases, the meter gives you a digital read out of the appropriate aperture at a given shutter speed. Some meters – especially older ones – uses a needle which you match to either a line or a second needle. Its a good idea to either get the sales person who sells you the camera or hand held meter to show you how to get the most out of it or can read the manual that comes with the meter or camera.
A camera’s internal meter always measures reflected light. In most cameras, this works very well for almost all the scenes most of us shoot. The problem comes when shooting a dark on dark subject or light on light subject. This is covered in other lessons, but the essential idea is that the meter thinks the whole world is 18 per cent grey. So, if you’re shooting a black cat on a dark chair, the meter will think it should be a lot lighter than that and will overexpose the image. Conversely, if you’re shooting snow on an overcast day, the meter will try to darken it to grey and it will underexpose the subject – even more than the usual grey of the day. Or an egg on a white table will come out muddy grays.
Understanding that, you can usually change the exposure to be more realistic.
Or, you can get a handheld meter which measures the light hitting the subject (incident light) and it doesn’t matter if the subject is white, grey, black, red or any other colour.
On most new style hand held meters, there is a white dome covering the sensor which is used for measuring incident light.
As a rule, the best way to measure incident light is to stand beside the subject and point the white dome towards the camera. This gives a good overall exposure. You can can also point the meter towards the light (or brightest light if there’s multiple light sources) to absolutely keep from over exposing the scene. This is especially good when doing a portrait. However, if the brightest light is coming from overhead and you’re shooting a portrait, point the meter at the camera or you’ll get deep dark shadows in the eye sockets which will make your subjects look like they have raccoon eyes.
If the subject is too far away to easily stand beside, you can find a spot with similar light to that hitting the subject, and measure the light the same way.
Another type of meter is the “spot meter” which can be hand held or built into many higher end cameras and is useful for more distant scenes you can’t just walk up to and use an incident meter. This measures reflected light, but only in a very small area – typically 1 to 3 degrees which is a small spot in an overall scene. The handheld meters tend to be the tighter 1 degree measurement. With a spot meter, you can determine the brightest point in a distant scene, as well as the darkest. Then, you can average the exposure between the two and hope to keep the highlights and shadows, or you can decide one is more important than the other. Those are choices you have to make yourself.
Many modern handheld meters include the ability to measure the light put out by a flash system – whether small portable flashes or big studio style flashes. Most photographers use light meters using incident light. Because flashes are very short exposure, the important part is the aperture. In most situations, especially using studio flashes, any other light – such as lamps, etc – will be so under exposed you won’t see the light in the picture.You can, however, also measure any ambient light and adjust the shutter speed to make any background light the same exposure as the flash or slightly under.
DIGITAL CAMERA HISTOGRAMS & EXPOSURE
Once you see the histogram, you can either adjust your aperture and/or shutter speed, or the exposure compensation to bring the histogram into line. (Again, refer to your user’s manual to find out how to do this if you don’t already know.) The right side of the histogram chart is the “highlight” side. The left side is the “shadow” side.
To make sure you have as much highlight detail as possible, the histogram bars should be as close to the right side (highlight side) of the histogram as possible without blocking up like this overexposed image:
If the image is underexposed like the image below, it can be rescued by lightening it in your editing program, but generally will gain noise (similar to grain in film photography.)
Which brings us to the concept of “Expose To The Right”
With digital cameras, many photographers are using an exposure method called “Expose to the right” or ETTR.
In the “Using the Histogram on digital cameras” section, you would have learned about keeping the histogram centered and not “blocking up” on either side.
With ETTR you would keep the histogram as far to the right as it can get without blocking up. This makes the image as bright as possible without going too far.
One of the effects of having too low an exposure on digital cameras is that it creates noise (random pixels) – especially in the shadow areas.
To use the ETTR method, make sure there is no gap to the right side of the histogram and that it is not “piled up” on the right.
What is the right exposure?
Not to make this complicated, but exposure is a choice you have to make. The exposure you choose determines how the image looks. But, we’ll start with a basic understanding and work up from there.
Exposure consists of five factors:
- how much light is in front of you – which can be changed by adding lights or flash,
- how sensitive the film is to light – called ISO (remember, I use the word “film” to refer to whatever medium used for capturing the image, whether it is the Digital Camera’s sensor or actually film,)
- the amount of light going through a lens – called the aperture,
- how long the film is exposed – called the shutter speed.
- what you want the image to look like, especially when light is beside or behind the subject.
If you’re camera does not have a built in meter – its really old. But, that’s okay. You’ll just have to buy a hand held meter. If you have an SLR or advanced point and shoot digital camera, spend some time with the manual to find out how to bring up the “Histogram” which graphically shows the amount of light in an exposure.
A Tip : – set your ISO to 100, set your camera to ƒ16 and the shutter to 1/125th of a second. (Some digital cameras are limited to ISO 200 – which means you have to cut your exposure by one stop, i.e. use 1/250th instead of 1/125th of a second) With this setting, take your camera out during a sunny day, put the sun behind you and shoot anything – you’ll have a well exposed image. This is called the “Sunny 16” rule.
To make life interesting, and your photography more creative, you can change the setting and still have the same exposure. These are equivalent exposures: Try going to ƒ11 at 1/250th of a second. Push it a little further at ƒ8 at 1/500th of a second. These are all the same exposure because the same total amount of light is hitting the film.
Of course, you’re not always going to shoot with the sun behind you on a sunny day. For other situations you need to be able to find out your exposure with a meter. This can be in your camera or hand held.
Looking at any scene, your meter will give you a suggestion as to what exposure to use. Most of the time this is fairly accurate.
Using your meter, take a reading off of something with mixed tones in shade on a sunny day – you’ll find the exposure is two or three stops slower than the “Sunny 16.”
A final note – A meter is very handy for getting your exposure, but it does have a limitation. As said earlier, the meter thinks the world is 18 per cent grey. Most of the world is kind of like 18 per cent grey, but not all of it.
Look at what you’re shooting. If its black (or very dark), your meter will try to make it grey – and make the exposure too light. Conversely, if you’re subject is white, the meter will try to make it darker – or 18 per cent grey.
High key and low key photos which will help you handle more extreme situations.
Note: Be aware that some digital cameras have exposure compensation built in to prevent overexposure. If exposure is too bright the highlights could be “blown out” and detail lost in the brightest parts of the image. By artificially “darkening” the image, the camera makers try to make sure the exposures aren’t too bright. This doesn’t affect all cameras but it does seem to be the case for some. That means that the exposure needed in lessons 2, 3 and 4 may be slightly higher than suggested in the lessons. You might use the “expose to the right” method.
A high-key photo is basically white on white. This style of photography conveys a feeling of lightness and clarity. Typically what happens is the camera wants to make the white of the photo – without dark areas to ‘balance’ the exposure – too dark. So your white’s become gray. You may have seen this particularly when shooting a snowy field on a gray day. However, exposing for high key is fairly easy.
With an in camera meter, you can measure the light hitting a white area, and open up two stops – such as changing the aperture from ƒ11 to ƒ5.6.
Put a large piece of white paper or white fabric on a table beside a large north facing window, place a white object such as a Styrofoam cup or egg in the middle.
Take a picture with the exposure that the in-camera meter suggests. You may have to use a tripod to keep the camera still if the shutter speed is too slow.
Next, meter off a white area and open up 1 and 1/3 or 2 stops – as described at the top of the this page. Compare the images.
This can work well for other scenarios where exposure is a tricky thing – like weddings where the bride is wearing white and the groom is in black. Quite often, the dress winds up blown out with no detail in the dress. By metering off the dress and opening up two stops you can prevent this from happening.
You can also use a hand held meter to measure the light hitting the subject, which will be more accurate than the in-camera meter.
Note: Be aware that some digital cameras have exposure compensation built in to prevent overexposure. If exposure is too bright the highlights could be “blown out” and detail lost int the brightest parts of the image. By artificially “darkening” the image, the camera makers try to make sure the exposures aren’t too bright. This doesn’t affect all cameras but it does seem to be the case for some. That means that the exposure needed in lessons 2, 3 and 4 may be slightly higher than suggested in the lessons. You might use the “expose to the right” method.
This is the opposite of the previous lesson. A low key photo is pretty much black on black, or at least very dark on dark. This kind of photo can create a sense of intimacy, foreboding, sadness, and / or heaviness. You might have a face or object rimmed with light in a silhouette, but dark on the side towards the camera and dark background.
The problem with shooting dark on dark is that the camera will try to lighten the image up making the picture look washed out and grey.
For this shot you’ll need a really dark cloth, preferably black, and an object that is dark or has some dark tones in it. You could shoot a portrait of a dark haired person in dark clothing against a black or dark background for a low-key portrait.
Note: Shooting an object or person that is very light or white against black has a different effect and is not really considered “low key”, although it can be striking image anyways.
A Tip: First, shoot the image with what you camera says is the right exposure. Very few in-camera meters will render this scene accurately. Now, take a meter reading on something dark/black that has the light hitting it and close the aperture two stops (i.e. if it is ƒ1.8 you’ll want to go to ƒ4.)
Depth of field – also sometimes known as depth of focus (although that does has a different technical meaning – some people use that term) – is an area many photographers feel some confusion over.
By changing the aperture in the lens, you can make the resulting picture have more of the picture in focus from near to far, or you can limit the picture’s focus on one place.
At ƒ1.8, the focus point will be much more defined with things in front of and behind the subject becoming softer looking the further from the subject they are. This is a very nice way to bring attention to the subject.
At ƒ22, the focus will seem to be sharp from very close to the camera to pretty much infinity. This is great for giving a sense of the place you shot the image, or for including many people in the image and keeping everyone clearly in focus.
However, there are limits to how that will appear in the final image.
Exercise: Find a subject/object that is still or will be in one place for a couple of minutes. Stand about 2 feet from the subject and focus on it. Set your ƒstop to 1.8 (or a close as possible to that based on the light) and set the shutter speed to get a proper exposure according to your meter. You can set the camera to Exposure Priority (AV mode) and let the camera set the shutter speed automatically. You should be using 50 mm lens or a zoom lens set to about 50 mm.
Now set your ƒstop to 16 and change the shutter as needed.
Step back to about 10 feet from your subject and re do the above settings – first at ƒ1.8 then at ƒ16.
To really push this exercise, try all the above steps with different lenses or at different lengths if you have a zoom lens – i.e.. try it at 35 mm and at 200mm, or whatever your zoom lens range is.
PS – a related subject is Bokeh which is a taken from a Japanese word ‘boke’ which roughly means blur or haze. When a photographer says an image has ‘good bokeh’ he means the out of focus areas have a smooth quality. Different lens and camera combination have different qualities of bokeh.
You’ve probably seen those pictures of a race car or bike rider where the subject is in fairly sharp focus but the background is blurry with streaks denoting speed. Perhaps you’ve seen a waterfall that looks like flowing silk. Or you seen a picture with someone totally frozen in place during an athletic moment.
These are a result of creatively using the shutter on the camera. High shutter speeds, such as 1/500th, 1/1000th, 1/2000th or higher (remember these are fractions of a second) create a stopped motion.
Alternatively, slow shutter speeds such as 1/15th, 1/4, or even whole seconds, creates a sense of motion through blurring of some part of the picture.
One of the issues is quite often if the shutter speed is too slow, an image can be blurry from “motion blur” which can detract from an image if the effect isn’t intentional.
Exercise: This is best done on a lightly clouded day that isn’t too dark or too bright. Find a friend with a bicycle or who likes to run. Go to an open area and set up your position. Have your friend ride or run past you many many times. You’ll need to do lots of exposures to get the shots.
First set your shutter speed as high as you can for the light – hopefully around 1/500 to 1/2000 – with the aperture as open as you can set (i.e. ƒ1.8).
As your friend moves past you, keep him or her in the viewfinder, turning yourself at the waist to constantly point your camera at your friend. Take lots of pictures for several passes. This is known as “panning.” You might want to try a couple of passes without tripping the shutter and practicing keeping your friend in the viewfinder as he or she goes past you.
Now, set your shutter speed as low as you can – I’d suggest around 1/30, remembering to set the aperture as high as you can for the light. Repeat the above panning motion to keep your friend in the viewfinder. Take lots more pictures, remembering to keep turning yourself at the waist as your friend goes by.
PS – to keep your images acceptably sharp, the rule-of-thumb is to keep your shutter speed at least the same as your focal length – ie a 50 mm lens should be used with a shutter speed of 1/50 of a second or faster. However, I find with most digital cameras you want to add another 50 % to that – so you want to shoot at 1/80 or faster (The one third of a stop equivalent of 1/75).
For sharp pictures a tripod is a very handy tool to free up your choice of shutter speeds.
Alternatively, you can hand hold a camera to surprisingly extended times with good technique: place the bottom of the camera body in your left hand and support its weight with that hand, then tuck your left elbow basically into your lower left rib cage. Finally hold the viewfinder close to your eye and use your right hand to trigger the shutter and further stabilize the camera. Breath in and let your breath out slowly while squeezing the shutter.
NOTE: most zoom lenses do not go down to f1.8 which is a general issue with those lenses. Just try and get as close as you can.
RULE OF THIRDS
The most used lesson in artistic composition is the rule of thirds. While there are lots of ways to compose pictures, this short cut always makes an image more interesting than most where the subject is dead center. If you’re shooting a close up of a person’s face or other object, putting it in the center is the thing to do. But, if you have a picture with a person in the center and lots of scenery around him or her – well, it could be improved.
A nice dynamic method of composing a photo is to have a diagonal line running through the photo, more or less from corner to corner. The line could be a street, a fence rail, a road or a shoreline. Anything which creates a line or division in the picture.
Whether the line rises or falls creates different feelings about the photo. Typically, for English speaking people and others with “left to right” direction of writing, if an line descends into the picture from top left to bottom right it appears to be entering the picture. If the line rises from bottom left to top right, it appears to be leaving the picture.
You can use those concepts to create specific feelings in your picture. Such as, a person standing beside a lake shore – if the line descends, it would suggest the person is entering the picture and thus would be, perhaps, happier and more inclusive. If the line is rising it would suggest the person is leaving and is thus more distant and removed.
Diagonal lines in photos can be used for what is called a “leading line” which helps the view be lead through the image in directed manner. Typically you’d have the lines “pointing” at the main subject of your photo – which puts the leading lines into the Negative Space (you’ll come across more about Negative Space in Lesson 11.)
Another dynamic composition tool is to include a “S” curve. As the name suggests, a major element of the composition would be an object such as a stream, path, railing, or other curved object that creates an “S.”
If the S is right facing and starts in the lower left corner and exits the upper right corner – the feeling for most English speaking people is that the picture is moving away from the viewer.
If the “S” is reversed, and starts in the upper left corner coming down to the lower right, the picture seems to be coming towards the viewer. This effect is from, I believe, learning to read left to right.
One way of making sure your composition is strong is to pay attention to the positive and negative spaces.
The primary subject of your photo, a person, building, toy car, whatever, is the “positive space.”
Negative space is everything else. Something you see in a lot of photography is things sticking out of heads, wires across the scene you didn’t see when taking the picture, and so on. This is just from paying so much attention to the subject that photographers forget what is in the background or surrounding the subject.