ClarkVision Photography: Astrophoto 1 Gallery

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image orion.35mm.rnclark.c10.09.2013.C45I4598-613_61sec.avg14.g2-bin4x4s.jpg is Copyrighted by Roger N. Clark, www.clarkvision.com

The Constellation Orion

The constellation of Orion is immersed in stars, gas and dust. In the center are the three bright stars making up Orion's belt, and below that, three stars making Orion's sword. The middle star of the sword contains the Great Orion Nebula, M42, a showpiece in small as well as large telescopes. Just below the left star in Orion's belt is the bright emission nebula, IC 434, and superimposed on it is a dark nebula called the Horsehead. The red arc to the left of the sword and belt is Barnard's loop. Above and to the left of Orion's belt is the orange star Betelgeuse, or Alpha Orionis. Many nebulae surround the region. The Milky Way galaxy is on the left edge of the frame, thus, many more stars show than on the right edge of the frame.

Technical. Canon 1D Mark IV 16-megapixel digital camera, Sigma 35 mm f/1.4 lens at f/1.4, ISO 1600. Fourteen 61-second exposures (14.2 minutes) were added along with shorter exposures for the core of the orion nebula: four 10 second exposures, four 5-second exposures, and five 1-second exposures (15.5 minutes total exposure). No dark frame subtraction, no flat fields, no noise reduction. Tracking with an astrotrac. The varied exposure times allowed a 16-stop dynamic range to be recorded.

The Exposure Factors, CEF, CEFA are measures of the relative amounts of light received from a subject. It can be used to fairly compare wildly different lens/telescope apertures and exposure times. For this image:

Modern DSLRs like the 1D Mark IV include on sensor dark current suppression and low fixed pattern noise at ISOs around 1600 and higher, making no need for dark frame subtraction. Modern raw converters correct for light fall-off and also correct for hot/dead/stuck pixels. This makes processing low light images easy: simply align and average.

To learn how to obtain stunning images like this, please visit my Extensive Articles on Photography .


Keywords to this image = astrophoto-1 nebula Messier digital_astro

Image ID: orion.35mm.rnclark.c10.09.2013.C45I4598-613_61sec.avg14.g2-bin4x4s.jpg

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Last updated November 07, 2018