Fundamentals of Photography presented by Keith Bauer.

Transcription

1 Fundamentals of Photography presented by Keith Bauer

2 Homework Assignment Composition Class will be February 7, 2012 Please provide 2 images by next Tuesday, January 31st Long edge 1024 pixels 72 dpi - Save at a size <= 300K srgb color space If you are sure you know how to prepare the image as attachment to me at kcbauer@juno.com If not: Bring in a CD, or USB drive next week

3 Exposure Triangle ISO Shutter Speed Aperture ISO

4 Shutter Speed

5 Simply controls the duration of the shutter Expressed on the camera as values like 1000, or 125, or 60 Which really mean 1/1000, 1/125, 1/60 Most modern SLR s have a shutter speed range from 30 to 1/4000 or 1/8000 Shutter speed either doubles or halves depending on which way you choose to move Controls motion

6 Aperture

7 A = * R 2 R= 1 So the Area is

8 A = * R 2 R=? What Radius will be required to create an area of 2 R = 2

9 1 1 * 1.4 = * 1.4 = 2 2 * 1.4 = * 1.4 = 4 4 * 1.4 = * 1.4 = 8 8 * 1.4 = * 1.4 = * 1.4 = 22

10 F-Stops or Apertures are a ratio of Focal Length / Size of hole created by the aperture Example: 50mm lens / 25mm hole = f / 2 50mm lens / 3 mm hole = f / 16 Hence: Small holes are represented as large f / stop numbers Large holes are represented as small f / stop numbers

11 Precise Focus is only possible at one distance - A point object will produce a point image Note the variables that affect Depth: Focal Length Subject Distance Aperture Circle of Confusion At any other distance the point will be defocused and produce a blur the shape of the aperture

12 Remember this little jingle in your head Big f / Stop Numbers = Big Depth Little f / Stop Numbers = Little Depth

13 DOF Preview If you have a DOF preview button on your camera This is a great way to see what will be acceptably sharp Remember - you are looking through your lens with it wide open DOF Preview stops down the lens to the selected aperture Let your eyes adjust - f/16 is pretty dark in there!!

14 ISO

15 Full Frame Sensor 1.6x Cropped Sensor

16 ISO - International Organization for Standardarization Doubling the numerical value doubles the sensitivity of the sensor Each camera has a base ISO Typically it is either ISO 100, or ISO 200 The range of ISO that a camera supports varies based on make/ model ISO ISO 6400 or (even 25600)

17 So why not just crank up the ISO Noise or Grain

18 f/2.8 f/4 f/5.6 f/8 f/11 f/16 f/22 f/32 1/30 1/60 1/125 1/250 1/500 1/1000 1/2000 1/4000 A X B Y A X B Y A X B Y A X B Y X B Y C B Y C Z B Y C Z Y C Z

19 There s more than Full Stops 1/2 Stop Increments f/4, f/4.8, f/5.6, f/6.7, f/8 f/9.5, f/11, f/13, f/16, f/19, f/22, etc. 1/30, 1/45, 1/60, 1/90, 1/125, 1/180, 1/250, 1/350, 1/500, etc 1/3 Stop Increments f/4, f/4.5, f/5, f/5.6, f/6.3, f/7.1, f/8, f/9, f/10, f/11, f/13, f/14, f/16 1/30, 1/40, 1/50, 1/60, 1/80, 1/100, 1/125, 1/160, 1/200, 1/250, 1/320, 1/400, 1/500, 1/640, 1/800, 1/1000, etc.

20 Exposure Triangle ISO Shutter Speed Aperture ISO

21 Light Meters

22 Two Types of Light Meters Incident Light Meters These measure the amount of light falling on the subject Very precise if you can place the meter in the same light as the subject

23 Two Types of Light Meters Reflected Light Meters The meter that is in your camera Measure the amount of light reflected from the subject

24 What s the Standard Reflected Light meters assume 18% of the light is reflected Hence they assume 82% of the light is absorbed or not reflected back to the meter That works fine in many situations North Blue Sky, Green Grass, Neutral gray card But... What happens if the subject doesn t reflect 18% of the light

25 Exposure Compensation Your mechanism to override the suggested metering value You can alter the suggestion in 1/2 or 1/3 stop increments Positive Exposure compensation adds light to the exposure Negative Exposure compensation subtracts light from the exposure

26 When to use it Extremes Predominately White or Black subjects Wedding dresses, snow Black Tuxedos,

27 Other Situations Many other situations You must be aware of what is in the viewfinder and what the meter is allowed to see

28 Metering Patterns Evaluative or Pattern or Matrix Partial Spot Center Weighted

29 Exposure Bracketing Taking Multiple exposures at varied exposure settings Example: 3 stop sequence at -2, 0, +2 Darker than suggested, At Suggested, Brighter than suggested Can be done automatically in your camera Most cameras will do a 3 stop bracket. Some will do 5, 7, or 9 shot brackets with increments of 1/3, 1/2, full or multiple full stops

30 Exposure Modes Program Mode (P) Camera controls Shutter Speed, Aperture and in some cases the ISO used to capture the image

31 Exposure Modes Aperture Priority (A or Av) YOU decide what aperture you want to use, and the camera selects the shutter speed that creates the correct exposure based on the ISO setting that you ve selected

32 Exposure Modes Shutter Priority (S or Tv) YOU decide what shutter speed you want to use, and the camera selects the aperture that creates the correct exposure based on the ISO setting that you ve selected

33 Exposure Modes Manual (M) YOU decide what shutter speed AND aperture you want to use to create the correct exposure based on the ISO setting that you ve selected

34 Flash

35 Flash Sync Speed The Sync speed is the fastest shutter speed on your camera when both the front and rear curtains of the shutter are completely open This typically somewhere around 1/200 or 1/250 At any shutter speed faster than the sync speed, the shutter is really a moving slit to expose the sensor

36 Standard Flash Sync Time 1st Curtain Exposed Sensor Single Flash Burst 2nd Curtain

37 High Speed Flash Sync Time Exposed Sensor 1st Curtain Strobes Flash Bursts 2nd Curtain

38 Front & Rear Curtain Sync Front Curtain Sync fires the flash as soon as the front curtain is completely open Rear Curtain Sync fires the flash just before the rear curtain begins to close

39 2 Components of a Flash Image Flash Ambient Aperture affects the amount of Flash that contributes to the exposure Shutter affects the amount of Ambient that contributes to the exposure

40 Fill Flash vs Flash as Main Light Fill Flash Intended too fill shadows with some light Not overpowering Should not be noticeable Usually requires negative Flash Compensation Can help control dynamic range of an image Flash As Main Light Flash becomes the only light source - i.e. Ambient contributes zero

41 Balancing Ambient and Flash 100% All Ambient - No flash 0% Flash Contribution to Exposure Balanced Fill Flash Ambient Contribution to Exposure 0% All Flash - No Ambient (Flash as Main Light) 100%

42 Lenses

43 What are all those Numbers Canon Zoom Telephoto EF mm f/2.8l IS USM Autofocus Lens Canon Zoom Telephoto EF mm f/4l IS USM Autofocus Lens Canon Zoom Telephoto EF mm f/4-5.6 IS Image Stabilizer USM Autofocus Lens $2100 $1281 $ Filter 77mm Filter 67mm Filter 58mm

44 Lens Perspective The perspective of the image changes based on the focal length of the lens camera to subject distance 300mm The longer the lens, the more compression occurs in the image Wide angle lenses seem to push subjects away 150mm 50mm 20mm

45 Filters

46 Circular Polarizer

47 UV Haze

48 Neutral Density

49 Graduated Neutral Density

50 Tripods and Heads

51 Tripods My advice Buy the best tripod you can afford

52 Arca Swiss Style Mount Ball Heads

53 Gimbal Mounts Wimberly 4th Generation Design Mongoose Kirk King Cobra...