Learning Outcomes. The Exposure Triangle. Revision - Aperture 23/09/2014. Basics and Application. At the end of this tutorial you will be able to:

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1 Waterford Camera Club Tutorials Damien Jackson Learning Outcomes At the end of this tutorial you will be able to: The Basics and Application Discuss the elements of the exposure triangle namely aperture, shutter and ISO Describe the effects of changes to these elements on the final photograph Discuss how these elements can be balanced to achieve the desired effect for the photograph Apply a number of settings to your camera in a practical situation and achieved the desired effect Aperture refers to the size of the opening in the lens that allows light through to hit the sensor and make a photograph The size of these openings are referred to as f stops 1

2 Aperture Range is particular to a lense Good lenses will often have a maximum of f2.8 throughout the entire zoom of the lense Kit or less expensive lenses might start at f4 or f5.6 at the near end and could end up at f6.3 when zoomed Aperture also has a part to play in Depth of Field (DOF) which is the elements of the photograph that are in focus and those not Large aperture openings (low f numbers) create shallow DOF Small aperture openings (high f numbers) create deep DOF Shallow Deep 2

3 Shallow Deep Aperture size on DSLRs is controlled via a dial on the camera or through a menu on the rear LCD Nikon Aperture control Cannon Aperture control Shutter speed refers to the duration which the shutters (or doors) within the camera open for to allow light to hit the sensor Shutters generally consist of a front and rear door which work together 3

4 The duration for which the shutters stay open effects the motion within a photograph The motion can either be frozen (High shutter speed or creatively allow some movement (low shutter speed) However, high and low are relative to the subject! E.G. A person walking v s a motorbike at 100kph Fast Shutter Speed Slow Shutter Speed Shutter speed is controlled by a dial on the camera body It can be seen on the rear LCD screen or when looking through the viewfinder at the bottom of the screen or higher end camera have a small window on top of the camera body 4

5 ISO- Revision ISO is the sensitivity of the sensor to light It is possible to adjust this sensitivity so that the exposure value for an image can be greatly enhanced without changing shutter speed or aperture size ISO- Revision Task: Look up at the lights on the ceiling When I turn off the lights, see how at first you can see very little but your eyes ISO adjust after a few seconds and you can see again E.g. going into the cinema on a bright day up the ISO Coming back out into the sun reduce the ISO 5

6 ISO- Revision However, this magic ISO sensitivity comes with a caveat! Setting the ISO too high may result in a lot of noise grainy images Example see how it looks ok at small size but noise appears when zooming in ISO Revision The key getting the image you want is the creative balancing of the 3 elements of Aperture, Shutter Speed, ISO Which leads us to the and its application! noise Getting the correct exposure for the type of image you want is a balancing act Sometimes it s very easy, sometimes difficult and often requires a compromise! Instead of thinking of it as an Exposure Triangle, think about and Exposure Pie Chart! 6

7 Exposure Pie Chart ISO 100 Exposure Pie Task In groups of 3, please discuss the approximate elements required for the following scenarios that you are trying to capture 1/250 Shutter Aperture ISO F 8 Scenarios A poppy that s blowing in the wind on a bright sunny day that you want to keep sharp and isolate from the background A waterfall on a dull day that you want to smooth the water A motorbike racer coming towards you at 120kph on a dull dreary day that you want pin sharp and isolated from the background A seascape at sunset that you want sharp from front to back and smooth water A poppy that s blowing in the wind on a bright sunny day that you want to keep sharp and isolate from the background Shutter 1/500 or faster Aperture f 2.8 or as low as possible ISO depending on shutter speed 7

8 A waterfall on a dull day that you want to smooth the water A motorbike racer coming towards you at 120kph on a dull dreary day that you want pin sharp and isolated from the background Shutter 2 seconds or slower Aperture f 16 if possible or smaller if required to get 2 seconds ISO 100 Shutter 1/1000th -1/1250th Aperture f 2.8 if possible or as near as possible ISO possibly r more depending on how dull it is A seascape at sunset that you want sharp from front to back and smooth water Shutter 3 to 30 second plus with use of an ND Filter Aperture f16 if possible or f18 - f22 if needed ISO 100 -Conclusion High shutter speeds for freezing sports and action may require high ISO leading to noise that s your compromise! Low apertures good for shallow DOF BUT you also need the subject away from the background and even better you are far away with a zoom lense High apertures not necessarily needed for landscapes particularly if you have no immediate foreground F10, ISO 100, 163 seconds Sample 1 Sample 2 f 4, 1/13th second, ISO 400 handheld pressed against a pole Have a go and learn, it costs nothing! 8

9 -Conclusion You need practice in the field to enhance your knowledge Eventually, you will get a feel for the light and the situation and will have an idea what settings to start with You may be wrong, adjust accordingly! Visualise what you are trying to achieve and think about the 3 element settings -Conclusion If fast shutter speed is not needed, keep ISO to minimum If you need a slow shutter speed and it s too bright even at the smallest aperture, you need an ND filter Landscapes don t always need f16 or higher Homework!!! Latest submission date: Thursday 5pm, 2 nd Oct to damien@djackson-images.com Your mission! One landscape image to include smooth flowing water One sharp action image in poor light One image with a sharp person/object and shallow depth of field All accompanied by a rationale (explanation) of why you used the setting you used to capture these images Please keep images to 1mb or less 9