These are Mark’s notes of photography U3a course, reproduced here for ready reference.
What are the 3 elements that control exposure?
- ISO/ASA or Film speed
- Lens aperture
- Shutter speed
ISO is the film speed or light sensitivity of the sensor in the camera. Choosing the ISO of the camera depends on the conditions when capturing the image. Bright and sunny outside = 100 ISO or Cloudy weather outside = 400 ISO. Also choosing a lower ISO number decreases the grain/noise in the image. i.e. If you’re doing a long exposure of star trails at night and you expose the image for about 2 hours and you want as little noise as possible, you would chose an ISO of 50 or 100. Common ISO’s are 25, 50, 100, 200, 400, 800, 1600 and 3200.
Aperture is the size of the opening in the diaphragm of the lens; this determines the amount of light passing through the lens. The smaller the number the larger amount of light. The size of the aperture is key in determining the depth of focus / depth of field when capturing the image. For example f 2 lets in maximum amount of light but has a very shallow depth of field, f 22 lets in only a very small amount of light but has a deep depth of field. Common f numbers are 2, 2.8, 4, 5.6, 8, 11, 16, 22 and 32.
Shutter speed is a measured amount of time the shutter allows light onto the film/sensor. Selecting different shutter speeds allows you to change the way an image appears i.e. 1/1000 sec will freeze a football player in midair, 1/125 sec will capture helicopter blades with a little movement in them and longer exposures will make fireworks reveal all their colours and seas turn smooth. Common shutter speeds are 1/1000, 1/500, 1/125, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2 and 1 second.
All three of these elements are measured in Stops, Stops is a term used in photography to describe a doubling or halving of the amount of light. As above with the examples of ISO, Aperture and shutter speeds all these figures are either half or double of the next number i.e. 1 STOP. If I captured an image at 1/125 sec and then an image at 1/60 sec the image captured at 1/60 sec would have 2x the amount of light as the shutter would have been open for twice as long. i.e.
1 stop = 1/2 or x2,
2 stops = 1/4 or x4,
3 stops = 1/8 or x8,
4 stops = 1/16 or x16
Combining these 3 elements in different amounts can change an image dramatically, so experiment with different shutter speed, apertures and ISO’s and you will find some very interesting results.
Most digital camera’s today are based on the old 35mm format, 3:2 ratio or as an example 6000pixels x 4000pixels. Also the standard length of the ‘normal’ lens is 50mm i.e. as what we see. Therefore all lens that are less than 50mm are referred to as ‘Wide Angle’ lens and any over 50mm are referred to as ‘Telephoto Lens’.
Lens also come as fixed or zoom lens, a fixed lens set at one focal length where a zoom lens can move between different lengths i.e. 28-200mm lens. With all lenses there are advantages and disadvantages, a fixed lens is usually of a superior quality where a zoom lens has a bigger range of applications / points of view. So choose carefully.
Remember when capturing an image always give your camera a steady base to shot from, brace yourself, control your breathing or use a tripod / monopod. Remember the rule of thumb for the length of your lens to reduce movement: Always use a faster shutter speed then the length of the lens until you become more proficient i.e. a 200mm lens = 1/250 sec, a 50mm lens = 1/60 sec or higher.
- 2000k – 3000k Sunset, flame, light bulb
- 5000k – 5500k Daylight, electronic flash
- 6000k – 10000k LCD screen, blue sky, example below
Be aware of the different colours of light, you don’t want to use your flash on camera which is (blue) on someone in front of a sunset (Red-Yellow), unless your after that effect. Try experimenting with different ways to mix the different colour temperatures.
Remember if you want to add some extra light to remove or soften shadows you don’t always have to use a flash, use a Scrim / bounce board to reflect some of the same coloured light to make your image pop. Remember Flash / Daylight = blue light, Sunset / light bulb = Red / Yellow and Fluro light = green.
When lighting people:
- Female – Ratio 1:1 or 3:1 – Flat lighting – Feminine
- Male – Ratio 1:3 – 1:9 – Textured – Masculine
- Try backlit, add some light behind them
- Different types of light to try Flash – Scrim – Harsh or Soft light
- Balancing two different light sources / colour temperatures
- Us light to add or subtract texture – Changing the lights angle can reduce or increase texture on the person
In the diagrams you can see that the Main light only hits Side A and the Fill light hits both A & B.
1st picture gives us a Ratio of 2:1. Both the fill and main are the same strength, therefore as A is hit by both sources of light it is doubled compared to B.
2nd picture gives us a ratio of 3:1. The main has twice the strength of light as the Fill, also represented by the Aperture of f 11 and f 8. Side A is hit with 2 from the main and 1 from the fill i.e. 2 + 1 = 3, side B = 1 only giving us a 3:1 ratio.
3 rd picture gives us a ratio of 5:1. The main has four times the strength of light as the Fill, also represented by the Aperture of f 16 and f 8. Side A is hit with 4 from the main and 1 from the fill i.e. 4 + 1 = 5, side B = 1 only, giving us a 3:1 ratio.
Some common rules:
- Rule of thirds
- POV = Point Of View
- Leading Lines
- Curvy lines
- Diagonal lines
- Close up
- Portrait Vs Landscape
- Filling the frame
- Framing using nature
- Leaving space
- Experiment with lighting
- Selective focus
- Blur background
- Cropping in camera
- Shutter Lag – be aware of your camera’s capabilities
- Holding a camera, bracing yourself
- Time Lapse
- Lighting subjects with or without flash
- Tele lens to compress the background
- Wide angle lens to accentuate objects closer in
- Flare – use it or suppress it
- Remember all information in the file is accessible to all
- Information captured is embedded in the file
- Backup all images
- Naming convention – as per handout
- Imbed a copyright on your image or in the metadata
Rule of thumbs
- Fastest lens has the smallest F stop i.e. f2.8
- Shutter speeds to use Vs lens length
- Depth of focus = 1/3 in front and 2/3 behind
- Can you download a camera fix for shutter lag???
How to shoot different subjects
- The moon
- Star trails
*** Remember better photography is learning from your mistakes. It’s similar to science, trial and error becomes science when you record your results****
- All images to be saved in an original folder
- All images you select as final images in separate folder
- Backup all images to an external Hard drive or device
- Name your images in a logical order
Renaming Multiple Files With Windows Explorer
Open Windows Explorer:
- Press the Windows Key with the E key or
- Click – Start, All Programs, Accessories, Windows Explorer
Find your images:
- Locate folder or create folder in which to store your images
Select all files:
- Sort files oldest to newest by date order
- Select all files by using CTRL + A or selecting all with your mouse
When all files are selected press F2
Type in the new name and then press ENTER
- 20150928_MM_Bob’s Birthday Bash
Results will be:
20150928_MM_Bob’s Birthday Bash (1)
20150928_MM_Bob’s Birthday Bash (2)
20150928_MM_Bob’s Birthday Bash (3) etc
There are 5 main camera modes most people use on their cameras. They are AUTO, (P) Program mode, (S) or (Tv) Shutter Priority, (A) or (Av) Aperture Priority and (M) Manual.
AUTO – Recommended for first time users of digital cameras, the camera has control of all settings, so point and shoot.
Program – Very similar to AUTO, the camera optimises the exposure to suit the subject by controlling the shutter, aperture and exposure compensation.
Shutter Priority – The camera is still shooting in an auto mode but you choose the shutter speed you want i.e. a fast shutter speed to freeze action or a slow shutter speed to blur movement.
Aperture Priority – The camera is still shooting in an auto mode but you choose the aperture to suit the depth of focus you require. You might chose a very large f# like f32 if you are capturing close up images and you want the most amount of focus possible or if your shooting a portrait and you only want the eyes in focus you might pick an f# with a shallow depth of field like f2.8, this can also throw backgrounds further out of focus.
Manual – You can pick and choose the shutter speed, aperture and ISO that suits you.
Other AUTO settings on cameras
- Portrait – Usually the camera selects a shallow depth of focus/field and triggers the flash to fire
- Landscape – best using a wide angle lens and the camera will not fire the flash
- Close Up – Camera selects centre of image to focus on, flash will fire, best with a macro/micro lens and tripod
- Sports – Camera will continue focusing while the shutter release button is slightly depressed, high shutter speeds are set, flash will not fire, best with a telephoto lens.
- Night Landscape – Slow shutter speeds automatically selected, best with wide angle lens and tripod, flash will not fire
- Night Portrait – Slow shutter speeds, use a self timer and tripod, wide angle lens and the flash will fire.
Remember prior to taking any images, set your ISO on your camera. 100 for bright areas, 400 for slightly darker areas and 400 – 1600 for unlit areas when use of a flash is required. Most of the auto type settings on your camera will sometimes change the ISO automatically to adjust for different lighting conditions.