Photography Basic By Henry C. Ng, APSA, EPSA

Topics Basic Photography theory Image sharpness Basic camera functions Digital Photography Basic composition

Basic photography theory Right amount of light ISO Shutter speed f-stop

ISO speed How fast it can absorb light ISO 100 ISO 1600 Higher resolution/quality Absorb light faster Lower resolution/quality Absorb light faster

f-stop The circular area that open from the lens f1.4 f2.8 f3.5 f4.0 f5.6 f8 f11 ::::: f22 f32 Shorter depth of field Let more light in (can take picture in lower light) Longer depth of field Let less light in (need more light to take a picture) Fast Lens Slow Lens

Depth of Field The distance from the front to the back of the focused subject that remaining sharp Depends on : f-stop and f-stop and the lens focus length the lens focus length

Depth of field (f-Stop) The distance from the front to the back of the focused subject that remaining sharp. f1.4 f11f22f5.6 Depth of field distance

Depth of field (Lens Focus Length) Wide angle Lens 12mm – 20mm Normal Lens 50mm – 55mm Telephoto Lens 135mm – above Longer depth of field Shorter depth of field

Depth of Field Distance Focus length F2.8 Aperture D = Focus Length / Aperture 50 mm/ 2.8 Example 1: f2.8 Example 2: f5.6 D= 2.8 / 50 = 0.56 mm 50 mm/ 5.6 D= 5.6 / 50 = mm

Image sharpness Depth of field Lens sharpness f1.4 f2.8 f4.0 f5.6 f8 f11 ::::: f22 f32 Longer Shorter Sharper f1.4 f2.8 f4.0 f5.6 f8 f11 ::::: f22 f32 Total Image Sharpness = f1.4 f2.8 f4.0 f5.6 f8 f11 ::::: f22 f32 Hi Low Less Sharp

Camera Basic functions Shooting modes Aperture priority (Av) Aperture priority (Av) Shutter Speed priority (Tv) Shutter Speed priority (Tv) Program mode (P) Program mode (P) Manual mode (M) Manual mode (M) Others OthersSportPortrait Sunny day Cloudy day, etc.

Picture-taking work flow Set ISO to the lowest (why – highest image quality) Select the lens focus length Set Tv or Av Using Av – if camera is on a tripod Using Av – if camera is on a tripod the biggest depth of field f-stop if want very sharp The largest f-stop if want short depth of field Using Tv mode – if hand held Using Tv mode – if hand held Stop motion – the fast enough shutter speed (just a little higher than the 1/ longest focus length of the lens used) Blurring – using slow speed. Test – if not enough light  set the ISO higher Test – if not enough light  set the ISO higher

Exposure Bracketing Why ? Sometimes, the light meter may not be able to measure the light exactly in the scene. Therefore, to make sure that we can have a good exposure picture, we bracket the exposures. Can be done in f-stop or shutter speed.

Digital photography What are the major differences ? Not much, instead of capturing the image light on film, it capture the light from the image and record it in digital numbers. The differences are so little, but using it is a lot different.

Digital photography Lens factoring 35 mm film/ full frame CCD APC CCD 35 mm film Digital CCD effective focus length = focus length x factor

Digital image file format JEPG TIF or TIFF RawEtc.

Histogram What it means: the number of pixels in the picture that has the same tone value White (254, 254, 254) Black (0, 0, 0)

直方圖 (histogram) 用途 What it means: the number of pixels in the picture that has the same tone value White 254 Black

直方圖 (histogram) 用途 What it means: the number of pixels in the picture that has the same tone value White 254 Black

直方圖 (histogram) 用途 What it means: the number of pixels in the picture that has the same tone value White 254 Black 0

直方圖 (histogram) 用途 What it means: the number of pixels in the picture that has the same tone value White (254, 254, 254) Black (0, 0, 0) Red Channel Green Channel Blue Channel Combine Channel

直方圖 (histogram) 用途 By looking the histogram, we can find out whether the image information is fully captured. If there is clipping, that means some of the image information was not captured. 圖像光位暗層位

The use of histogram info By looking the histogram, we can find out whether the image information is fully captured. If there is clipping, that means some of the image information was not captured.

Basic Composition Rule Rule of third

Basic Composition Rule Rule of third

Basic Composition Rule Rule of third

Basic Composition Rule Rule of third Locations that most attracting human attention

Beautiful scene Nice subjects placements But still lacking something Many times we may not able to make that perfect composition

Fill the empty area Much tighter composition and making the picture standout

-Back lighted -Subjects stood out -No empty space - perfect composition

Image Lighting Front light (image appears flat) Side light Back light