Tag Archives: infrared

Energy-Efficient Lights Could be Making Light Pollution Worse

Earth’s city lights. Image by Craig Mayhew and Robert Simmon/NASA GSFC.

City lights drive back the night a little more each year, disrupting ecological cycles, and the switch from orange-yellow sodium lights to bluish-white LEDs might be making the problem worse.

Read/listen to my full story at KJZZ’s Arizona Science Desk:
Artificial Light Pollution On The Rise Globally, LEDs Might Be Making It Worse

Dirty photography no more?

Nikon D40 digital SLR camera with visible CCD image sensor
Photo: Kaspar Metz/Wikimedia Commons

If it takes a certain daring – or disregard – to crack the case on your computer and blow it free of dust, then it takes even more gumption to tackle cleaning your digital camera sensor. In this article, I’ll walk you through the basics of sensor cleaning, give you the rundown on which tools you’ll need (and which ones you won’t), show you how to get the gunk off your lenses and throw in some general upkeep tips for good measure.

How should a digital camera be cleaned?

Starlight, star bright, first shot I snap tonight

Infrared photo of Webster's Falls
Photo: Marcus Qwertyus/Wiki Commons

Photography is all about light; it’s right there in the name: photo (“light”) + graph (“means of recording”). So how do you shoot in the gloom between the golden hours? Well, you have a few options. You can pop in a flashbulb. You can try your hand at painting with light – that is, fiddling with f-stops and shutter speeds to let more light in over a longer period. Unfortunately, flashbulbs tend to wash out photos, and setting up longer exposures tends to limit your photographic freedom.

Night-vision cameras and attachments get around these problems, either by amplifying existing light or working with a different kind of ambient “light” – aka infrared radiation, either from body heat (thermal IR) or from an active IR illuminator attached to the camera. Today, infrared and ultraviolet cameras also make useful tools for inspections and field work. But how do they work, and what is their history?

How Night-vision Cameras Work