As I was getting ready for bed last evening the Internet started to come alive about the color of a dress. I took one look at the photo, said to my wife "The Internet is being stupid about a dress. It's clearly white and gold," and minutes later I was sound asleep. I woke up this morning to an angry wife, who thought I was a crazy person: she saw it as blue and black without question. (Spoiler Alert: In reality, the dress is blue and black.)
Marital bliss aside, what Tumblr user Swiked posted is, from a technical perspective, a terrible photo. That's what caused raging Twitter debate and household strife across the world. Another image of the same dress, shows that it is dark blue and black.
When I look at the infamous photo, I don't see true white and gold, but that's what I thought the true colors were in reality. It looked like the white balance was off, likely due to a mix of daylight and tungsten lighting, which gave a pure white dress a slightly bluish hue. If you've ever shot photos at a wedding and found that the bride's pure white dress looks a little blue or orange in photos, you've experienced the same thing.
But what was actually going on was a bit more complex. The image is shot in mixed lighting for sure. You can see the strong backlight behind it; from what I can tell it's a mirror, reflecting daylight coming in from the outside. This is mixed with the artificial light that's illuminating the room. Light has different temperatures—daylight tends to be blue (hence, the sky), tungsten lighting is closer to yellow, and fluorescent tubes give off an unearthly green hue. A camera recognizes the type of lighting that's in a scene and attempts to change its response to color to compensate. Shooting in mixed lighting makes that difficult and leads to color shift in images.
But exposure is a big issue as well. A camera examines a scene in order to determine what ISO, aperture, and shutter speed it should use to record a photo. Very basic meters are calibrated to record a scene that's basically gray in terms of luminosity (18 percent gray, if you want to get technical). More advanced meters in digital cameras have scene-recognition functions that deal better with scenes with mixed lighting and a harsh backlight like this, but let's face it—the dress photo wasn't shot with a Nikon D4S, it was likely snapped by a smartphone.
The combination of a very dark subject with a very bright background resulted in this mess of a photo. Highlights are blown out in the background, and the dress is way overexposed. The EXIF data isn't present on the image that was posted to Tumblr, but there's also a good chance that a higher ISO affected the color fidelity; smartphone cameras often struggle with capturing accurate colors when the sensitivity to light is increased.
How could this have been avoided? You don't need a fancy camera to take a picture of a blue and black dress to make it look blue and black. We could have continued to spend our day yesterday concentrating on escaped llamas had the photographer simply avoided the harsh backlight. Even those who see the dress as blue and black will admit that it's much too bright compared with the way that dress looks in real life. If you're in a situation where you can't avoid a backlight, dialing in negative exposure compensation (represented by a +/- icon in your smartphone app, if it's available) will quickly darken or brighten the scene to make the image on the camera's screen better represent what's in front of your eyes.
Want to try and take some photos of the dress yourself and see what kind of results you get? It's available to purchase from Amazon UK. Make sure to check out the customer reviews.