Saturday, August 29, 2015

Nice Change Background Image photos

Some cool change background image images:

change background image
Image by flurryofsmoke
A tonemapped version of the previous image where the Earthshine appears. The Earthshine is the dark part of the lunar disk that is illuminated by the solar light reflected back by the Earth, whereas the bright crescent is directly illuminated by the Sun.

The image was created and processed as followed:
-I took 130 exposures shot with 5 different exposure times, from 0.1s to 4s;
-I converted the RAW files to linear FITS files with Nebulosity and preprocessed them (subtraction of the camera offset, flat-field correction and subtraction of the sky background);
- I stacked the images in an HDR fashion using the IDL language;
-the crescent, almost 3000 times brighter than the Earthshine, cast a halo of light all over the image, which I had to remove with some sort of deconvolution process. Some residuals of this halo are still there, close to the terminator (separation bewteen the crescent and the Earthshine);
-I tonemapped the luminance channel in Photoshop, while conserving the colors (red- and blue-to-green ratios);
-finally, I changed the color balance so as to make the crescent appear grey in average.

change background image
Image by kaburke10
Used my own original image :
Used autotone and autocontrast tool to make the picture look a little better as a whole. Selected the books, using the quick selection tool then made a "Layer via copy." Did the same thing for the boy in another layer. I sharpened books a lot, added drop shadow, increased brightness and contrast, changed curves.
Blurred the background and made it black and white.
Sharpened the boy, increased exposure, decreased offset. Cropped picture.