Photo detail

Camera Maker Nikon Corporation Camera Model NIKON D90
Aperture f/6.3 Exposure Value 0 EV
Exposure Program Unknown: 0 Exposure Time 1/160 sec
Flash No Flash Focal Length 18 mm
ISO 200 Metering Mode Pattern
Date/Time 2013:09:14 08:33:53 Resolution Unit Inch
X Resolution 240 dots per ResolutionUnit Y Resolution 240 dots per ResolutionUnit
Compression Jpeg Compression Contrast 0
Exposure Mode 0 Saturation 0
Scene Type Directly Photographed Sharpness 0
Subject Distance 2.82 Caption While all the guides show popping a chalk line to mark the locations of the ridges, I quickly realized that lots of slippery chalk on a nice smooth metal surface is not a very good idea!