|A "false" HDR exposure of the Milky Way stars reflecting in Oxbox Bend, Grand Teton N.P. ~ © Royce Bair|
(Canon 5D Mark III, Rokinon 24mm f/1.4 @ f/2.0, 13 seconds, ISO 6400)
|Exposure for sky|
Second Exposure Problems: Making a longer exposure second exposure is very time consuming because I usually turn on the camera's "Long Exposure Noise Reduction" feature which also takes a "black" exposure for the same amount of time, compares the two images, and cancels out the hot/noisy pixels in your final image. I gladly take this additional time for the increase in quality; however, images with water will also reflect cloud changes (between the exposures) and star movement in the longer, second exposure. Water automatically magnifies the brightest stars and diminishes the lesser stars. It also has a tendency to make each bright star produce a "long" reflection —similar to the way a rising moon reflects on the water. My longer (4X) second exposure greatly exaggerated those lengthy star reflections, causing them to look weird and out of character. To avoid this, and still get better foreground detail I turned to False HDR: False High Dynamic Range Imaging (sometimes called Fake HDR).
Standard HDR vs. False HDR: In regular HDR imaging, one takes at least three exposures: one at the normal exposure value, one at a +1.0 EV (or higher), and one at a -1.0 EV (or lower). These three images are blended, "fused", or tone-mapped together using HDR software, i.e. Photomatix —with the final image extending the dynamic range of the scene.
In False HDR, one manipulates the original exposure to obtain the other two exposure values. This is best accomplished using the Adobe Camera Raw Converter.
|In the Adobe Camera Raw Converter, use the "Exposure" slider to obtain your 3 Exposure Values|
|Save one image at the neutral or "0.00" EV. Save the second image at the "+1.00" EV, and the|
third image at the "-1.00" EV (16-bit RAW images can be converted to EV's up to +/- 2.00 stops).
|Here are my three converted images: Normal exposure, +1.00 EV, and -1.00 EV.|
These are saved as 16-bit TIF files.