If you’ve ever been curious how some of the beautiful desktop wallpaper images in Apple’s OS X operating system were shot, you’re in luck. It seems Apple forgot to scrub the EXIF data from one of the El Capitan wallpapers, giving you a glimpse into how it was shot, and how it was edited.
The slip (if it was a slip) was discovered by New Zealand photographer Omi Manav Choudhary, who shared the news on Reddit. And while there are 49 photos (of 51 total wallpaper options) in El Capitan, Choudhary says this is the only one that still has its EXIF data intact.
According to the EXIF, the image was captured on August 6th, 2013 at almost 9PM using a Canon 5D Mark III and a 17-40mm f/4L lens shot @ 17mm and f/4. The photographer, Sungjin Ahn, was shooting in Manual, at ISO 1600 and a shutter speed of 30 seconds.
Interestingly, if you dig a bit deeper, you’ll also find editing notes. The photo was brought into Photoshop CS6 and it got quite a bit of post-processing love (as have other Apple wallpapers):
Please darken some of the stars that are a bit smaller and darker, so there is a little more difference in the starfield.
Please remove some of the noise in the sky.
Please darken the sky a bit overall, but more so in this brighter area that is circled.
Can we refine this area so it doesn’t look like it was duped from the spot to the left?
Please fill in this area close to the edge with more tree so it doesn’t create awkward negative shapes.
As the stars transition towards the horizon, they should become much less dense. You can see in the original, there are fewer stars towards the bottom.
Less pink in this section of the sky. Please reference the original which is more blue.
Overall, stars can be a touch sharper.
The brightness of the stars should be brightest at the top, and slowing fading out towards the bottom.
We can stand to brighten the largest stars at the top here.