Why are solar flares often difficult to see in ordinary visible light?

Solar flares are often difficult to see in ordinary visible light because the energy release occurs in the Sun's transparent atmosphere, rather than in the photosphere, which is the visible surface that emits most of the light we see from Earth.12

While a solar flare involves a massive release of energy, the photosphere receives relatively little of that energy directly. Consequently, in white light, a flare typically appears only as a few small, faint bright spots, whereas it would be much more prominent if viewed in specific wavelengths, such as the Hα line, where it can appear significantly brighter than the surrounding chromosphere.1