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Ultra-long exposure with the lot

I was astounded by the array of light trails recorded on the ultra-long exposure image (approximately 12 hour exposure). The photo was taken using the Slow Shutter Cam app on an iPhone 4, starting at approximately 18:00 on 20120518 and ending just after 06:00 on 20120519.


When you set these up to run overnight, you can never tell exactly what is going to be there in the morning. I always have a sense of anticipation and thrill when I head out to conclude the exposure.


The main focus of my efforts with this shot was to deliberately capture the light trail produced by a "satellite flare" event - to see what they look like when captured with an iPhone camera. As suggested by "artcole" (see the comments on , I used the "Heavens Above" website to obtain a prediction of an Iridium satellite flare event visible from my location. The sunlight reflected from the Iridium 45 satellite, one of the 50+ satellites forming the Iridium satellite communications constellation, was predicted to be visible at magnitude at -4 (i.e., a similar intensity to Venus) on an azimuth of 358 degrees and elevation of 21 degrees.


The flare event was captured right on schedule, at the predicted location and brightness - see the short bright trail above the crown of the gum tree towards the right hand side of the image. If you move the cursor over the image above, the location is shown with a note (i.e., a rectangular box with a label).


Despite the presence of scattered clouds during the exposure, a good assortment of star, planet and aircraft light trails were also recorded. The star and planet trails arc smoothly from top right to centre left. The dots are recording the path of aircraft with their flashing landing lights on as they climb away from Canberra Airport (off to the right of this image. I have absolutely no idea what manoeuvres the aircraft or helicopter that produced the tighter continuous light trail arcs was engaged in!


Barton, ACT, Australia.


iPhone 4 - A pair of photographs were taken with an iPhone 4 using the Slow Shutter Cam app (that allows an unlimited "bulb" exposure time in Light Trail mode) using a "Sensitivity" setting of 1. The first was an exposure length of approximately 60 seconds under relatively bright ambient light conditions, followed by an ultra-long exposure of approximately 12 hour length spanning the hours of darkness.

TouchRetouch - Several point-size artifacts in the ultra-long exposure image attenuated.

Photo Power - Automatic lighting correction applied to the ultra-long exposure image.

Blender - The two photographs (taken from the same camera position using a tripod mount) were blended together to add greater definition to the buildings and trees in the foreground, and to add a lighter blue color to the sky region (60:40 blend ratio, default blend mode).

Snapseed - Overall and selective lighting changes applied. Image cropped.

Iris - Image resized to 2592 x 1936 pixels.

Camera+ - Rounded black border added.

PaintShop Pro X4 - Digital camera speckle noise attenuated (60% fine and large scale, 60% blend).


(Filed as 20120519_iPad3 022 SlowShutterCam-TouchRetouch-PhotoPower-Blender-Snapseed-Iris-Camera+-PaintShopProX4-DNR-60006060.JPG)

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Taken on May 19, 2012