Week 2

Review Homework Assignments

Review Last Session

It’s not that simple…

T 1/125 1/160 1/200 1/250 1/320 1/400 1/500

A 4.0 4.5 5.0 5.6 6.3 7.1 8.0

ISO 100 125 160 200 250 360 400

Modern cameras have 1/2 or 1/3 stops for shutter speed, aperture and sometimes ISO.

Get familiar with what your camera does and remember the “full” stops.

Camera View Finder

• (Almost) the same picture as the sensor will see

• Focus Point(s)

• A lot of data

View Finder Frame Accuracy

• Canon EOS 60D: 96%

• Canon EOS Rebel T2i: 95%

• Nikon D40: 98%

Nikon D40 Viewfinder

http://www.imaging-resource.com/CAMDB/print_page.php?directory=ND40&page=viewfinder&model_name=Nikon%20D40

Canon EOS 60D

Canon Rebel T2i is similar, but does not have a battery indicator.

Other Displays• Exposure Info (shutter, aperture, ISO)

• Exposure/Focus Lock

• Exposure Compensation

• Electronic Level (some cameras)

• Image review

• Histogram

• Other Status Information (drive mode, flash, ...)

An Experiment

Determine Correct Exposure

• Camera Meter

• What does it measure?

18% Gray

Scenarios

• Take a picture of a white rabbit in snow

• Take a picture of a black cat on black velvet

• What do we get?

Rabbit or Cat?

Exposure Compensation

• When taking pictures in extreme lighting conditions of extreme brightness levels

• For snow, over-expose by 1.5 to 2 stops

• Use the exposure compensation function of your camera

Histogram

• To judge the right exposure

• Need to compensate for extreme situations (e.g. snow or very dark situation)

• http://www.kenrockwell.com/tech/histograms.htm

I don’t have a 18% gray card!

Yes, you do!

The Palm Trick

Measure the palm of your hand so that the light that hits the scene also hits your palm.

Then “open up” one stop (e.g. go from aperture 8 to 5.6, or from 1/500s to1/250s)

MeteringExposure: Shutter speed, aperture, ISO

The camera’s meter will take the selected ISO into account, an external meter needs to be configured correctly.

Metering will result in a combination of exposure settings.

Any equivalent exposure can be used.

Metering Modes

• Evaluative or Matrix Metering

• Center-weighted average Metering

• Spot (or partial spot)

How to Meter?

• Group photo with light coming from the font

• Beach scene with backlight

• Portrait

• Landscape

Handheld Meters

• Reflected Light

• Incident

Cheaper Alternative

http://www.esdevices.com/products/luxi

Assignment

Find  different  scenes  that  require  different  metering  modes.  Take  three  pictures  for  each  scene  using  all  three  metering  modes.  Take  a  fourth  picture  using  your  “built-­‐in”  gray  card  to  determine  the  correct  exposure