EXPOSURE Light and the Camera

Transcription

1 EXPOSURE Light and the Camera

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9 EXPOSURE

10 OVER EXPOSURE = TOO MUCH LIGHT is hitting the sensor

11 UNDER EXPOSURE = NOT ENOUGH LIGHT is hitting the sensor

12 Exposure (the amount of light hitting the sensor) is determined by the relationship between three things: APERTURE SHUTTER SPEED ISO

13 APERTURE SHUTTER SPEED ISO Aperture Shutter Speed Use your camera s exposure meter as you change your settings to check whether you re achieving a proper exposure for your lighting conditions. ISO Exposure Meter

14 APERTURE

15 APERTURE (F-STOP) and EXPOSURE Aperture means opening. F-stop = the size of your aperture. The bigger the number, the smaller the aperture, the less light passes through and hits the sensor.

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17 APERTURE (F-STOP) and DEPTH OF FIELD Another feature of aperture is that it controls Depth of Field (DoF) = How much of your scene is in focus / how big is your focus range

18 * * If we are changing aperture, why is this image consistent in exposure?

19 APERTURE (F-STOP) and DEPTH OF FIELD Shallow depth of field; wide aperture or narrow (and high f-number or low)?

20 APERTURE (F-STOP) and DEPTH OF FIELD Deep depth of field (wide or narrow aperture?)

21 APERTURE (F-STOP) - REVIEW Aperture means opening Controls the amount of light hitting the sensor Fire hose vs garden hose Measured in f-stops Smaller f-number = larger aperture, larger hole fire hose!, more light hitting the sensor (and vice versa) Aperture controls Depth of Field

22 SHUTTER SPEED

23 SHUTTER SPEED and EXPOSURE The length of time the sensor is exposed to light Measured in fractions of a second: 1/10, 1/500, 1 The longer the shutter is open, the more light will pass through to hit the sensor Low light situations will require the shutter to be open for longer than high light situations

24 SHUTTER SPEED and CAPTURING MOTION

25 SHUTTER SPEED and CAPTURING MOTION

26 SHUTTER SPEED and CAPTURING MOTION

27 SHUTTER SPEED and CAPTURING MOTION Inside a Camera at 10,000fps - The Slow Mo Guys CmjeCchGRQo

28 SHUTTER SPEED and CAPTURING MOTION Fast or slow shutter speed?

29 SHUTTER SPEED and CAPTURING MOTION What about this one?

30 SHUTTER SPEED and CAPTURING MOTION...this one?

31 SHUTTER SPEED and CAPTURING MOTION...this one?

32 SHUTTER SPEED and CAPTURING MOTION (the problem with shutter speed) The whole image is blurry. Why?

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34 SHUTTER SPEED Controls how long light can come through the aperture to hit the sensor Measured as fractions of a second (eg. 1/250, so 1/1000 is much shorter than 1/10) The longer the shutter is open, the more light will hit the sensor, the more TIME you are recording; the more TIME you are combining into one image, the more blur you ll have Blur can come from MOTION OF THE SUBJECT or MOTION OF THE CAMERA (camera shake) Shutter speeds longer than 1/60 of a second will be subject to camera shake; use a tripod!

35 ISO

36 ISO ISO = the sensitivity of the sensor Low light > High ISO ISO and film a roll of film has a particular ISO; you are stuck with that ISO until you change your roll of film SO set your ISO according to the lighting situation you are in (you usually won t need to change it while you re shooting in the same general area) You can raise the ISO when you find you don t have enough light to get a proper exposure. But be careful...

37 Noise.

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39 You can only open the aperture so far! A tripod will allow you to use a longer shutter speed w/o camera shake, so you can use a lower ISO

40 ISO ISO = the sensitivity of the sensor (low number = low sensitivity, vice versa) USE THE LOWEST ISO YOU CAN GET AWAY WITH. For a sunny day, you can use a very low ISO, like 100 For a cloudy day, you re more likely to use somewhere around 400 For evening and indoor scene, 800 INCREASING YOUR ISO will increase NOISE and unintentional SATURATION (loss of data; data = detail) Use a tripod whenever you can instead of hiking up your ISO

41 WHITE BALANCE

42 WHITE BALANCE Different sources of light have different colors, or temperatures Our camera processes this differently than our eyes; this can give a color cast on our images We have to set a white balance: we are checking against a neutral gray to make sure there is no color there (replicating how we saw the scene originally) Can use AWB (auto white balance), one of the built-in modes, or can set a custom white balance This is something that s easy to do in post in Lightroom!

43 WHITE BALANCE - GRAY CARD We can create a custom white balance using a Gray Card Take a photo with a neutral gray in it to use your camera s custom white balance feature Need to take a new gray card shot for each new lighting scenario