Those glowing nebula photos get accused of being 'fake color' — and the accusation misses what's actually happening. The pictures are real data, honestly translated from light your eyes were never built to see.
Every telescope shoots in black and white
Professional telescope cameras don't capture color at all. They record grayscale images through filters — one exposure through a red filter, one through green, one through blue — and combining those exposures rebuilds the color, the same trick color photography has used since the 1860s. When the filters match what your eye would see, the result is close to what you'd witness through a porthole, just far brighter, because the telescope's bucket collected light for hours instead of your eye's fraction of a second.
The translator's choices
Astronomers often filter tighter than red-green-blue: narrowband filters that isolate single wavelengths emitted by specific atoms — hydrogen, oxygen, sulfur. Assigning each its own display color turns an image into a chemical map, where you can literally see which gas is where in a nebula. The famous Pillars of Creation images use exactly this. The colors are assigned, but they aren't invented: each one traces a real, measured signal. It's less like painting and more like translating — the grammar changes, the meaning doesn't.
Seeing light that has no color
Your eyes register wavelengths from about 380 to 700 nanometers — one octave of an electromagnetic keyboard that runs for dozens. Webb observes infrared out to 28.5 microns, forty times redder than the reddest red you can perceive; Chandra catches X-rays from million-degree gas around black holes. Light at those wavelengths doesn't have a 'true color' — no color your eyes could report is any truer than another. Shifting it into the visible isn't deception; it's the only way a human can look at it at all. The alternative to translated color isn't honest color. It's a blank page.
How to read a space image honestly
The right question isn't 'is this real?' but 'what am I looking at?' — and the caption always tells you. Observatories publish which instrument and filters made each image, and whether the palette is natural, representative, or a chemical map. That's the same deal this site makes with every number on every page: nothing invented, everything labeled. The universe doesn't need embellishing. It needs translating — carefully, and on the record.