Photograhy for Noob’s
- What is a “stop”?
A stop in photography term is the measurement of light (measured in EV). +1 stop means that the light is double from the current value. Similarly, -1 stop means half of the light entering your camera. Of course you can have 1/3 stops or 1/2 stops.
- What are the common ISO values for a film?
ISO is the measure of the sensitivity of the film, and the common ISOs are: 50, 100, 200, 400, 800, 1600, 3200, and 6400. Each of these is 1 stop away from the next, e.g. ISO200 is double the sensitivity of ISO100. There are other ISO films/settings available in between.
- What is a shutter?
Shutter in most SLRs is film plane shutter and it is the blade in front of the film plane that controls the amount of light hitting the film. It is normally closed and opens briefly when you press the shutter release button to expose the film. Another type of shutter is diaphragm shutter and it is usually mounted on the lens. A 3rd type of shutter is electronic shutter used in some digicams.
- What are the common stops for shutter speed?
Common shutter speed goes like this: 30”, 15”, 8”, 4”, 2”, 1”, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000, 2000, 4000. Each of these is 1 stop away from the next. Notice that they roughly double the value from the next, as when we double the time, double among of light will enter the camera.
- What is an aperture?
Aperture is the diaphragm located in the lens for controlling the amount of light entering the lens. Aperture sizes are stated as (focal length)/(f-stop value), e.g. f/8, meaning the area of the opening is the current focal length of your lens divided by 8. Notice that at a given f-stop, e.g. f/8, the aperture opening is smaller for wide angle when compare to telephoto. Since we are talking about area, when it doubles it is multiply by square root of 2 of the previous one. Hence it goes from 1 to 1.4 to 2 to 2.8, etc. (see below).
- What are the common stops for aperture (f-stop)?
Common aperture goes like this: f/1 (widest), f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32 (narrowest). Again, each is 1 stop away from the next. An easy way to memorize them is that they multiply in pairs. ( 1-2-4 , 1.4-2.8-5.6)
- How do we calculate stops?
Assuming the light entering the camera remains constant, we can play around with the value of the ISO, shutter speed and aperture value while maintaining the same exposure.
Ex 1: Assuming ISO 100 is constant. f/8 at 1/250s is equivalent to f/11 at 1/125s. Why? When we set the aperture from f/8 to f/11, we are reducing the light by 1 stop (half the amount of light now enters the camera). So to maintain the same exposure, we need to increase 1 stop from the shutter speed, hence 1/250 to 1/125 (time now is double, so we have double the light).
Ex 2: Assuming shutter speed is fixed at 1/250 and initially ISO is 100. Aperture is f/5.6. If we change the aperture to f/11, what is the ISO value we need to maintain constant exposure? Since from f/5.6 to f/11 are -2 stops, we need +2 stops from ISO, hence we need ISO 400.
- How do shutter speed and aperture affect a picture?
High shutter speed is used to freeze a motion while slow shutter speed is used to create “motion blur”. Smaller aperture has a greater depth of field (DOF) and larger aperture a shallow DOF. Shallow DOF is useful for subject isolation. 3 factors that affect DOF are: aperture size, focal length, and object to camera distance. Wider aperture size (smaller f-stop number), longer focal length, and shorter object to camera distance all decrease DOF, resulting in a blurer background.
- How can I reduce camera shake?
A few things you can do. Fist of all, learn the correct shutter release squeezing technique. The way to do it is to lightly tap on the shutter release button to achieve autofocus. Once everything is in order, lightly squeeze the button all the way down. Second, pay attention to the shutter speed. As a rule of thumb, the minimum shutter speed is 1/focal length, so e.g. you are at 200mm, the shutter speed should be above 1/250s. If not, you’d better find something stable to support your camera (e.g. top of car, railing, lamp post) or use a tripod. Thirdly, tug your elbows in to form a triangle to support the camera. If you are using an SLR, use your forehead to support the camera too.
- Why is my digicam having deeper DOF at the same focal length and f-stop when compare to an SLR?
Anybody like to answer this? Since the sensor size digicam is much smaller then the standard 35mm size on the SLR, its lens has a shorter “equivalent focal length” then the SLR’s. Remember from above, the aperture size is (focal length)/(f-stop value)? Now at f/8, the actual aperture size on the digicam is much smaller then that on the SLR, resulting a deeper DOF.
- What is the relationship between focal length and perspective?
When we zoom from wider angle to telephoto, if we tried to maintain the same subject size, the background will appear to be further away from the subject at wide angle and closer at telephoto. This is called perspective compression and is also a useful technique for subject isolation.
- What other techniques are available for subject isolation?
Some other effective ways for subject isolation is by using contrast and/or color difference between the main subject and the surrounding/background.
- What are program, aperture priority, shutter priority, and manual mode?
In program mode, the camera sets both the aperture and shutter speed according to the exposure value measured by the meter. In aperture priority mode, you set the aperture you want, and the camera selects the shutter speed according to the metering. In shutter priority mode, you select the shutter speed while the camera sets the aperture. In manual mode, you control both shutter speed and aperture. Note that the meter does not come into play in manual mode (except for indication), hence exposure compensation has no effect in this mode.
- What are the different metering modes?
In matrix (evaluative) metering, the camera uses multiple segments of sensors divided across the frame to measure the scene and decides the best exposure value based on the data pre-stored in the camera’s firmware. In center-weighted metering, the measurement is based primarily on a center circle in the viewfinder (how big is the circle depends on your camera). Spot metering determines the exposure by concentrating on a small area at the chosen metering spot.
- When to use each mode?
Matrix metering is generally the easiest and most commonly used. However, in tricky lighting situation, the camera can be fooled (e.g. backlight or snow condition). In this case you can use the spot meter to help you achieve the proper exposure. Center weighted mode is used when your subject is large and you want to use the average of the entire object for exposure.
- What is mid-tone and what is its relation with the meter?
Mid-tone is 18% gray when we go from black to white. Our eyes see things in logarithm manner, so middle gray is at 18%. Mid tone is not limited to gray, and can be red, green, blue, or other colors, as long as it is at 18% value. How does this relate to the meter? All meters measure the exposure and give the result in 18% gray. This means that if you use spot meter and white piece of paper, the paper will appear gray in your pic. Matrix metering will try to correct it by referring to the data stored in the camera. So how do we use spot meter? You can get the exposure value of a given lighting condition by taking measurement off an 18% gray card. Or, you can learn to compensate by experience (e.g. pure white is about +2 stops then mid tone, while pure black is –2 stops).
- When is spot metering useful?
One example where spot metering comes in handy is when you have backlit situation. In this case, the light source is behind the subject (e.g. a model), so what you do is spot meter off the model’s face. You then compensate the exposure depending on the skin tone of the model.
- What is bracketing?
When you turn on bracketing, the camera will take 3 consecutive pictures: the normal one, one with a lower exposure compensation and one with a higher compensation. E.g. if you set the bracketing value to 1/3EV, the shots will be taken with –1/3EV compensation, normal, and +1/3EV compensation. This is done when the photographer isn’t quite sure of the actual exposure value, and kiasu a bit doesn’t hurt. J
- Why are some people turning on the flash in broad daylight?
What they are doing is called “fill flash”. In very strong sunlight under sunny day, the subject’s (e.g. a model) face is unevenly lit. To have a more natural look, fill flash is used. In auto fill flash mode the camera will automatically determine the correct amount of flash to fire to properly expose both the subject and the background. Another way of doing this is by using one or more reflectors.
- When should I not use the flash?
When taking night scenes! Your flash won’t be powerful enough to light up the whole building/mountain especially when they are so far away! Use a tripod instead. Only use the flash when taking foreground objects that are within your flash range (see 21 and 23 below).
- What is “guide number”?
Given a focal length and an ISO, guide number of a flash = subject distance * f-stop. The higher the guide number, the more powerful your flash is and the further away it can shoot. For example, for a flash of GN = 12 (at ISO 100, m, 50mm), it means that using a 50mm lens and an ISO 100 film, at f/4 your flash can reach a distance of 12/4 = 3m away.
- What is flash sync speed?
When the flash fire, it only fires for a very short moment. For camera with film plane shutter, the shutter actually opens and closes by 2 blades. The 1st blade opens up the film plane and the 2nd one closes it. So there exists a time when the 1st blade just finish passing the plane when 2nd one just start to close up. This is the flash sync speed of the camera. Any shutter speed higher then this would mean that the 2nd blade closes in before the 1st one leaves the plane. This resulted in a slit narrower then the original film plane, and if the flash fires momentarily, it will only illuminate part of the film exposed by the slit. Different camera has different flash sync speed. Diaphragm and electronic shutters do not exhibit this limitation.
- What is slow sync mode?
In this flash mode, the camera continues to open the shutter after firing the flash to illuminate your main subject, so that the darker background can be captured. E.g. you can use this mode at night to shoot people with a night scene, without which the background would appear dark. To use this mode, you must set up a tripod.
- What is rear sync mode?
In this flash mode, the camera fires the flash at the end of the exposure of the slow sync mode. This mode is effective in capturing a subject that moves, resulting the subject leaving a trail of light behind.
Tips for taking better pictures
- What makes a good picture?
A good picture is always produced by a photographer who thinks ahead of what he/she wanted to express before pressing the shutter. Think of each picture as an essay to describe something. Ask yourself what do you want to write in the essay. You’ve not succeeded if the viewers look at your picture and never say “wow!”
- What is “rule of thirds”?
When a subject is placed at the center of a frame, it usually looks boring and static. A better way of placing the subject (or anchor points) is to put it (them) at the “thirds”. Looking into your view finder/LCD, try to imagine the frame is divided into 3 equal parts both vertically and horizontally. These dividing lines are the “thirds”. Try it out now.
- Why is it important to keep the horizon level?
The horizon of the earth represents the ground, and we are used to seeing them, well, horizontal. Imagine a picture with the sea horizon slanting one side. Won’t you naturally expect the water would pour out of the picture? J
- Can the above rules be broken?
Of course you can, rules are meant to be broken! Once you mastered these rules properly, you can break them to achieve more creative form of photography. In other words, a subject doesn’t always need to be at the 3rd! Try to use your imagination, be creative, and experiment.
- How to make effective use of space in the picture?
The amount of space placing in the picture is normally related to personal taste and what the photographer would like to express. For a landscape picture, placing the horizon at the upper 3rd (resulting more space below the horizon) brings a sense of distance, while placing it at the lower 3rd would show the spaciousness of the sky. For a person/subject that is moving, you would probably want him/it to move into the frame, so you leave more space in front of him/it. If you do it the other way, the person would look like he is trying to walk out from your picture.
- What is framing?
Framing is another method to bring attention to your subject. You enclose the subject with some surrounding objects. Please ask the instructor to demonstrate. J
- How would lines and S-curves affect the photo?
S-curves and lines that exist in nature or man made buildings can be used to lead the eyes to your subject. A photo with an s-curve normally looks more graceful.
- What is anchoring?
Anchoring refers to insertion of point of interests into your picture to hold the picture together. E.g. you are shooting a seaside sunset. The picture would be rather plain if it is just the sun, the sky and the sea. Now if you include one or 2 seagulls or silhouette of a couple into the picture, they become the anchors and make the scene more interesting.
- What is layering in landscape photography?
Layering is a technique used in landscape photography to divide the picture into 3 parts: foreground, center and background. This injects a sense of dimension into the otherwise rather empty picture, and leads the viewers’ eye.
- Why is subject isolation important?
Each photo is supposed to have one and only one subject/topic. The topic can either be an object, a person, an expression, a relationship, a feeling, or a view that you, the photographer, would like to tell your audiences, the viewers. By picking out the subject that you want to photograph and isolating it from the surrounding, you are focusing the viewers’ attention to what you want to express. Any other objects in the photo that is not part of your topic or at least complement your main subject are just distraction and shouldn’t be there. If they do complement the subject, they should not overpower it.
- Why is lighting important?
When god created light, there came along the shadows. A good mix of light and shadows can usually add a lot mood to a picture. Different lighting will give different feel and impact. A few of the different lighting: spot light, high/low key light, backlight, moody light, and colorful light. Use them effectively to create beautiful pictures. (Please ask the instructor to illustrate).
- Any other composition tips?
If possible, try shooting a subject from different angles. Eye level is usually the most common but unimpressive angle. Try an angle higher then the eyes by climbing on top of something (e.g. going to the 2nd floor of a building) or a lower angle close to the ground. Look around the subject to find a clean background so you can better isolate the subject. Choose an angle that minimizes the distractions. Move your feet, walk around.
Simple is great. Simple is better. Try to keep your picture simple and uncluttered A common mistake made by most newbies (myself included) is to try to include too many things in your picture. As mentioned above, try to isolate your subject, remove all the irrelevant stuffs and include only those that support your subject/topic.
- How to take fireworks?
Use lower ISO so that you can open up your shutter longer. Find yourself a good position, set up the camera on the tripod, and use a shutter release string and bulb mode. If possible, anticipate when the next firework will shoot, and open the shutter before that so that you’ll catch the “tail”. Use f-stop of f/11 or f/16, and approximate exposure time of 2-5 secs.
- How to make “silky water” out of the river/waterfall?
Depends on how “silky” you want the water, use a shutter speed that is slow enough for your taste. You can experiment by starting from 1/30s and longer. Remember to use a tripod. In sunny days you might have trouble achieving low shutter speed – in this case, an ND (neutral density) filter will help. NDx2 will reduce a stop, NDx4 2 stops, and NDx8 3 stops. They can be stacked.
- How to shoot the “streaks of lights” on city streets?
Again, the trick is using long exposure. Set your camera to shutter priority mode and choose a shutter speed that is “long enough” to make the streaks of your liking. Take care to check the aperture value such that it is not out of your camera capability. Put your camera on a tripod, and release the shutter when the traffic is moving. You can either use a shuttle release string or the timer, but with the timer capturing the right moment can be tricky. Experiment and shoot until you are satisfied.
- How to proceed from here?
Take more photos! Think before you shoot, and when you are not shooting, look at other people’s photos. If you like them, ask yourself why is it good. If not, ask yourself why not? Learn the good and bad points about them, and do the same for your own photos.
Recommended books for reading:
- John Shaw’s Nature Photography Field Guide
- John Shaw’s Closeups in Nature
That’s all. Good luck and happy shooting.
And thanks for coming.