上圖是蘋果公司 OS X El Capitan 共 51 幅桌布中的其中一幅，本來只是普通的風景照片，但攝影師 Omi Manav Choudhary 就發現，並到 Reddit 上分享，原來它是唯一沒有刪去 EXIF 的照片，引起了網友們的好奇心，到底照片是怎樣拍的呢？

根據顯示出來的 EXIF，照片是由 Sungjin Ahn 以 Canon 5D Mark III 配 17-40mm f/4L 鏡頭，於 2013 年 8 月 6 日大概 9pm 拍攝，手動模式設定 ISO 1600、快門速度 30 秒、光圈 f/4、焦距 17mm。

(照片放到 LR 裏顯示的內容)

不單如此，更有網友 hrrrrsn 表示從 metadata 中發現到 editing notes，可以一窺照片是怎樣後製︰

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.

如有興趣了解更多，可以按此瀏覽更多 EXIF 資料，及按此下載原圖。

Source: Reddit via PetaPixel