Star Trail Photography

Because the Earth rotates, the stars are not at fixed locations in the sky.  The stars appear to move, more or less toward the west.  To photograph the tracks the stars make across the sky a camera is pointed to the heavens from a fixed location with a long exposure.

The stars appear to rotate around both the north and south poles in the sky.  Generally one can only see one of these rotations.

Stars very near the poles appear almost stationary in the sky, while stars closer to the equatorial plane move quite fast.  All stars move about 15 degrees per hour in right ascension (horizontally), but do not move in declination (vertically).

Star trail photos are often spectacular.  The major problem creating these exposures is that it takes a long time (several hours) to create a single image.

Above:  A 3 hour exposure that captured a number of airliners (horizontal lines) in addition to the stars.

To create these images one only needs a camera with lens that can perform time exposures on 'B' or 'Bulb' mode.  With my Canon Rebel T2i I use the Manual setting on the dial and then choose 'Bulb.'  

One also needs a tripod and a cable release or lockable shutter release.

Above:  In this long exposure created at Arches National Park some vehicles were captured in the image as well.  These lights (under the arch) could be painstakingly removed with photoshop or left as they are they add to the artistic nature of the shot.

NIGHT PHOTOGRAPHY

Above:  The Sénanque Abbey in Provence, France in a long, night

exposure that revealed the Milky Way and a sky full of stars.

LONG EXPOSURE PHOTOGRAPHY TIPS

SLOW SYNC MODE

The most basic night shot that is attempted (and screwed up) is a person in the foreground with a nightscape behind.  They want a shot of a person on the balcony with the Las Vegas strip in the background, for example.  Most photographers will use the flash, which blacks out the background.  The simple solution to this problem is "slow sync mode."  The camera automatically makes a long exposure, metering for the background light, but also uses the flash.

Above:  Stars, the setting sun, and a country road in a 30 second exposure.

STAY OPEN ALL NIGHT

Even cheap point-and-shoot cameras can be used for time exposures, but the shutter speed is often capped at 30 seconds.  Longer exposures require a digital S.L.R. camera which can stay open until you run out of battery.  S.L.R. refers to a single-lens reflex camera that typically uses a mirror and prism system that permits the photographer to view through the lens and hence see exactly what will be captured, as opposed to viewfinder camera where the image could be significantly different from what one sees through the viewfinder.

KEEP IT STEADY

Regardless of the camera one uses, it is necessary to use a tripod.  When buying a tripod consider weight, size and portability.  Choose an aluminum, metal alloy, or carbon fiber tripod over a plastic one as the plastic ones will break quicker.  I have a very heavy metal tripod that I use regularly. . . but at times I don't feel like carrying it around because of its weight.  A good tripod costs between $200 and $600.

EXPERIMENT

Above all one has to be prepared to experiment because there are so many variables and few written guides for the long-exposure photographer.  You could read the manual that comes with your camera but  the manuals are generally written by someone who does not have a command of the English language and writes in technical jargon that is foreign to most amateur photographers.

HOT & STORMY FLORIDA

The potential exists for the most dangerous severe storm outbreak of the season this weekend across the Deep South from southeastern Louisiana to the coastal Carolinas.

Thunderstorms will likely fire across the western Gulf Coast from southern and eastern Texas into Louisiana tomorrow as a storm system now situated over northwestern Mexico gathers strength in the Gulf of Mexico.

The early risk from the developing storm is blinding downpours and the potential for flash flooding.  This will be welcome news to many locations across the Florida panhandle which is suffering from a years-long drought.  The severe weather accompanying the rain will not be welcome.

All of the ingredients come together for a severe storm outbreak on Saturday as the storm system pushes across the central Gulf states.  Thunderstorms are forecast to gather into dangerous clusters on Saturday.  The thunderstorms in the clusters could produce damaging wind gusts greater than 70 mph, large hail, tornadoes, and flooding downpours.

Some individual storms will develop outside of the clusters, and these storms will have the greatest risk of spawning tornadoes.  New Orleans, Biloxi, Mobile, Pensacola, Ft. Walton Beach, Panama City, and Tallahassee are among the cities lying in the path of the greatest threat for severe storms.

On Sunday, severe thunderstorms will rattle the coastal Carolina and coastal Georgia with some thunderstorms stretching back into north-central Florida.  North of those storms a drenching rain will expand across the Southeast.

BUDWEISER SHOOTOUT

Its race weeks in Daytona and the forecasters are saying that the severe weather should not affect the first big race of the series, the Budweiser Shootout, Saturday night.

There's a chance for a shower or thunderstorm during the day on Saturday but as has been the case all winter we're likely too far south to receive any beneficial rains from this system. . . nor race-canceling rains (however one wants to look at it).

Slightly cooler temperatures (and clearer skies) are forecast for next week.  After the storms pass to our north our temperatures should drop roughly 10° F (from the mid-80°s to the mid-70°s).

The Budweiser Shootout is the last major race before the highly anticipated Daytona 500 on Sunday, Feb. 26.  Cloudy but warm temperatures are currently forecast for the 26th.  14 day forecasts are highly unreliable. . .but it has been warm and partly cloudy most of the winter so it is safe to assume that pattern will continue.