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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
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