Digital Photography Part 3 Creative control

Péter Tarján2 What are creative controls? The key factors that decide how a composition will look: focusing white balance shutter speed aperture focal length Cameras can set these automatically (except focal length), but learning how to use them manually helps in getting great pictures.

Péter Tarján3 Shutter speed Shutter speed is one of the 2 factors that determine exposure. Shutter speed is the time interval during which the shutter is open and the sensor is getting light. For every full stop, the amount of light on the sensor is (about) doubled/halved. Reasons to set shutter speed manually: avoid camera shake freeze movement blur movement panning increase/reduce depth of field The standard shutter speeds: …1/30 sec 4 sec1/60 sec 2 sec1/125 sec 1 sec1/250 sec 1/2 sec1/500 sec 1/4 sec1/1000 sec 1/8 sec1/2000 sec 1/15 sec…

Péter Tarján4 Effect of shutter speed

Péter Tarján5 Steady shooting When shutter speed is low, camera shake may blur the image. Its effect can be greatly reduced by holding the camera correctly. Hold the camera firmly with both hands. Stand with your feet slightly apart. Hold your elbows close to your body. Squeeze the shutter button gently. Get additional support from knees, walls, ledges… Experiment what works for you. More good tips here: the-camera-with-your-hands/3k0expg5xjecw/2#

Péter Tarján6 Freezing movement For freezing movement, you need a fast shutter speed. But how fast? It depends on how fast the subject is moving across the frame – not the actual speed! Distance to the subject also counts. Subjects moving towards or away from the camera need slower shutter speed than those moving across the frame. Also: for close subjects, you can use a flash – it almost always freezes the movement. SubjectSpeedDistanceefl across Direction of motion toward diagonal car80 km/h30 m100 mm1/1000 sec 1/250 sec1/500 sec train160 km/h50 m35 mm1/500 sec1/125 sec1/250 sec jogger10 km/h5 m100 mm1/750 sec1/180 sec1/300 sec jet plane800 km/h2000 m400 mm1/500 sec1/125 sec1/250 sec

Péter Tarján7 Effect of freezing movement

Péter Tarján8 Blurred movement Fast shutter speeds sometimes fail to convey the dynamism of a moving subject: a speeding car may look just like a parked one. Choosing a slow shutter speed blurs the movement, which may work better. Shutter speed shouldn’t be just slighly slow (blur without the artistic effect) or too slow (image may be unrecognizable). Rule of thumb: 4 stops slower shutter than what you would use for freezing the action. Panning : tracking a subject with the camera, using slow shutter speed, causing the subject to remain sharp and background to blur. Technique: hold the camera steady with two hands swing your shoulders from your waist, without moving your feet leave more space in front of the moving subject than behind follow the subject across and press the shutter button smoothly take lots of shots to get a few that work

Péter Tarján9 Blurring

Péter Tarján10 Extended exposures In low light, exposures of more than 1 second may be needed. Some tips: Support the camera. If the camera is supported, you are free to choose any shutter speed. Choose shutter speed/aperture to suit your needs. Choose the lowest ISO setting to minimize noise. Use self-timer/shutter release cable/remote control to fire the camera. Avoid the widest aperture settings to maximize image quality. If you can’t get a slow enough shutter speed, use a neutral density filter. Low-light shots tend to be overexposed by the camera; correct for that or use manual exposure. Camera supports whatever you find beanbag unipod (monopod) tripod (pan-tilt head, ball-and- socket head) telescopic legs center column handle head (with camera platform and quick- release shoe) crank

Péter Tarján11 Effect of extended exposures

Péter Tarján12 Depth of field In principle only objects at a given distance from the lens are sharp – everything closer or further away are blurred to varying degrees. The blur is invisible for a given range of distances around the focusing distance, so everything within that range looks sharp. This range is called the Depth of Field (DoF). Depth of Field depends on a number of factors. Factors determining DoF: aperture: the smaller the aperture (higher f-stops), the more the DoF. focusing distance (subject distance): the farther away the focus is, the more the DoF. focal length (zoom setting): the shorter the focal length (=wide angle) the more the DoF. “circle of confusion”: how big a circle you are willing accept as “point”. Subjective! It also depends on image magnification and how closely it is viewed.

Péter Tarján13 Depth of field: aperture effect 7.4 mm focal length (35 mm efl), focus on red die

Péter Tarján14 Depth of field: focal length effect focus on red die, f/4.0

Péter Tarján15 Depth of field: focusing distance effect efl 65 mm, f/3.2

Péter Tarján16 Depth of field: size matters Is the yellow die sharp? It depends on the magnification and your definition of “sharp”.

Péter Tarján17 Maximizing depth Use the controls together to maximize DoF: use wide lens/zoom setting, close the aperture, get further away from the foreground elements. Multipoint autofocus helps. The through-the-lens (TTL) viewfinder of bridge and SLR cameras may give an idea of DoF.

Péter Tarján18 Minimizing depth Throwing things out of focus is usually much more difficult on digital cameras – SLRs rule here. The main things you can do: use long telephoto use wide aperture get close to subject Why? Keeping parts of the picture blurred can help concentrate on the main subject and can result in more powerful pictures.

Péter Tarján19 More DoF tips DoF in close-up photography is extremely narrow – fight it or use it to your advantage focus DoF<1 cm! Bokeh: out-of-focus background with smoothly blurred highlights when taking pictures of people or animals, always focus on the eyes! We tend to look at them first and blur is the most annoying when in the eyes

Péter Tarján20 Aperture and lens resolution In several picture-taking situation, more than one shutter speed-aperture combination yields a shake-free picture and enough DoF. In that case, you can take one other factor into consideration: lens resolution. Lenses provide their best resolution at their mid-apertures. Wider settings decrease resolvable detail because lenses work better optically near their center than their edges. At small apertures, diffraction on the edges of the aperture itself causes another drop in image quality. Quality decrease due to diffraction is worse for smaller sensors. Thus, SLRs can use narrower apertures (typically f/22) before diffraction becomes significant than zoom compacts (typically f/8) or bridge cameras (f/11). Bottom line: use a mid-aperture setting whenever you can.

Péter Tarján21 Focal length Changing the focal length of the lens by zooming changes the angle of view of the camera. This is a very important compositional tool: useful for cropping when taking the picture allows you to maximize sensor effectiveness changing it together with the subject distance, it gives more flexibility in choosing background allows you to take very different types of shots.

Péter Tarján22 Perspective Perspective is the optical effect that makes distant objects appear smaller than close ones and parallel lines seem to converge. It gives vital clues about depth in the picture. Perspective depends only on the distance! But using different focal lengths can change the picture because telephoto lenses are used from further away – and that changes perspective. same perspective! different perspective

Péter Tarján23 Manipulating the background Whether using wide- angle or telephoto lenses, you can end up with very similar-looking pictures. What can change dramatically when you change focal length (and subject distance) is what is in the background and how it looks (DoF, perspective…).

Péter Tarján24 Wide-angle lenses Wide-angle lenses offer a wider field of view than our eyes. Uses: fit a lot of things into the frame exaggerate foreground create a wide DoF Problem: barrel distortion

Péter Tarján25 Telephoto lenses Telephoto lenses offer a narrower field of view than our eyes. Uses: bring distant objects “closer” “compress” distances between objects create a narrow DoF Problem: heavy, magnifies camera shake