Photography Basic By Henry C. Ng, APSA, EPSA. Topics Basic Photography theory Image sharpness Basic...

Photography BasicPhotography Basic

ByBy

Henry C. Ng, Henry C. Ng, APSA, EPSAAPSA, EPSA

TopicsTopics

Basic Photography theoryBasic Photography theory

Image sharpnessImage sharpness

Basic camera functionsBasic camera functions

Digital PhotographyDigital Photography

Basic compositionBasic composition

Basic photography theoryBasic photography theory

Right amount of light

ISO Shutter speedf-stop

ISO speedISO speed

How fast it can absorb lightHow fast it can absorb light

ISO 100 ISO 1600

•Higher resolution/quality

• Absorb light faster

•Lower resolution/quality

• Absorb light faster

f-stopf-stop

The circular area that open from the lensThe 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 FieldDepth of Field

The distance from the front to the back of the The distance from the front to the back of the focused subject that remaining sharp focused subject that remaining sharp

Depends on :Depends on : f-stop and f-stop and the lens focus lengththe lens focus length

Depth of field (f-Stop)Depth of field (f-Stop)

The distance from the front to the back of The distance from the front to the back of the focused subject that remaining sharp.the focused subject that remaining sharp.

f1.4 f11 f22f5.6

Depth of field distance

Depth of field (Lens Focus Length)Depth of field (Lens Focus Length)

Wide angle Lens12mm – 20mm

Normal Lens50mm – 55mm

Telephoto Lens135mm – above

Longer depth of field Shorter depth of field

Depth of Field DistanceDepth of Field Distance

Focus length

F2.8

ApertureD = 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 = 0.112 mm

Image sharpnessImage sharpness

Depth of fieldDepth of field

Lens sharpnessLens 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 functionsCamera Basic functions

Shooting modesShooting 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 Others

SportSportPortraitPortraitSunny daySunny dayCloudy day, etc.Cloudy day, etc.

Picture-taking work flowPicture-taking work flowSet ISO to the lowest (why – highest image Set ISO to the lowest (why – highest image quality)quality)Select the lens focus lengthSelect the lens focus lengthSet Tv or AvSet Tv or Av Using Av – if camera is on a tripodUsing Av – if camera is on a tripod

the biggest depth of field f-stop if want very sharpthe biggest depth of field f-stop if want very sharpThe largest f-stop if want short depth of fieldThe largest f-stop if want short depth of field

Using Tv mode – if hand heldUsing Tv mode – if hand heldStop motion – the fast enough shutter speed (just a little Stop motion – the fast enough shutter speed (just a little higher than the 1/ longest focus length of the lens used)higher than the 1/ longest focus length of the lens used)Blurring – using slow speed.Blurring – using slow speed.

Test – if not enough light Test – if not enough light set the ISO higher set the ISO higher

Exposure BracketingExposure Bracketing

Why ?Why ?

Sometimes, the light meter may not be Sometimes, the light meter may not be able to measure the light exactly in the able to measure the light exactly in the scene. Therefore, to make sure that we scene. Therefore, to make sure that we can have a good exposure picture, we can have a good exposure picture, we bracket the exposures.bracket the exposures.

Can be done in f-stop or shutter speed.Can be done in f-stop or shutter speed.

Digital photographyDigital photography

What are the major differences ?What are the major differences ?

Not much, instead of capturing the image Not much, instead of capturing the image light on film, it capture the light from the light on film, it capture the light from the image and record it in digital numbers.image and record it in digital numbers.

The differences are so little, but using it is The differences are so little, but using it is a lot different.a lot different.

Digital photographyDigital photography

Lens factoringLens factoring

35 mm film/ full frame CCD APC CCD

35 mm film Digital CCD

effective focus length = focus length x factor

Digital image file formatDigital image file format

JEPGJEPG

TIF or TIFFTIF or TIFF

RawRaw

Etc.Etc.

HistogramHistogramWhat it means: the number of pixels in the picture What it means: the number of pixels in the picture that has the same tone valuethat has the same tone value

White (254, 254, 254)

Black (0, 0, 0)

直方圖直方圖 (histogram) (histogram) 用途用途What it means: the number of pixels in the picture that has the same What it means: the number of pixels in the picture that has the same tone valuetone value

White 254

Black 0

215 215 215

135

135 135135

215

35

35

215

直方圖直方圖 (histogram) (histogram) 用途用途What it means: the number of pixels in the picture that has the same What it means: the number of pixels in the picture that has the same tone valuetone value

White 254

Black 0

215 215 215

135

135 135135

215

35

35

215

直方圖直方圖 (histogram) (histogram) 用途用途What it means: the number of pixels in the What it means: the number of pixels in the picture that has the same tone valuepicture that has the same tone value

White 254

Black 0

直方圖直方圖 (histogram) (histogram) 用途用途What it means: the number of pixels in the picture What it means: the number of pixels in the picture that has the same tone valuethat has the same tone value

White (254, 254, 254)

Black (0, 0, 0)

Red Channel

Green Channel

Blue Channel

Combine Channel

直方圖直方圖 (histogram) (histogram) 用途用途

By looking the histogram, we can find out whether the By looking the histogram, we can find out whether the image information is fully captured.image information is fully captured.

If there is clipping, that means some of the image If there is clipping, that means some of the image information was not captured.information was not captured.

圖像光位暗層位

The use of histogram infoThe use of histogram info

By looking the histogram, we can find out By looking the histogram, we can find out whether the image information is fully whether the image information is fully captured.captured.

If there is clipping, that means some of the If there is clipping, that means some of the image information was not captured.image information was not captured.

Basic Composition RuleBasic Composition Rule

Rule of third

Basic Composition RuleBasic Composition Rule

Rule of third

Basic Composition RuleBasic Composition Rule

Rule of third

Basic Composition RuleBasic Composition Rule

Rule of third

Locations that most attracting human attention

Beautiful sceneNice subjects placementsBut still lacking something

Many times we may not able to make that perfect composition

Fill the empty areaMuch tighter compositionand making the picture standout

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

Image LightingImage Lighting

Front light (image appears Front light (image appears flat)flat)

Side light Side light

Back lightBack light