What lure flash does

A shiny surface on its own attracts nobody. What works is change: flash, dark, flash again. Steady shine is read by the fish as part of the background and doesn’t stand out.

Where the frequency comes from

A lure turns to the light first with one side, then the other, and every turn produces a flash. The faster it spins or rolls, the more frequent the flashes — so frequency depends on the retrieve, not on the finish.

Each class has its own

A spinner gives a steady, frequent rhythm because the blade spins continuously. A spoon gives sparse, heavy flashes in time with its roll. A hardbait with a tight action flickers on its sides finely and fast. Three classes, three different rhythms with the same mirror finish.

A pause is part of the rhythm too

When a lure stops, the flashing stops completely. On a suspending hardbait this pause is the longest, and it’s exactly that “flashing — then not” transition that the eye picks up better than a steady retrieve without stops.

Surface shape decides too

A curved plate throws a flash sideways in a narrow beam, a flat one throws it wider and weaker. So two equally shiny metal lures flash differently, and that’s set by geometry, not by the polisher. In metal you can’t pick flash apart from shape — unlike a hardbait, where body and finish are independent.

Sun, cloud and time of day

The light source is the sun or the sky. In overcast weather and at dusk, the flash weakens for every lure at once, and in direct sun a mirror surface gives a sharper contrast than a matte one does. That’s a property of the weather, not of the lure: the finish stays exactly the same, and the signal it gives off changes through the day on its own. So the very same lure looks different in the morning and at midday.

Flash lives only where there’s light

At depths beyond the lit zone, there’s nothing to give off. There a mirror lure and a black one work the same way: nothing to reflect, and all that’s left is a silhouette with vibration. Only a glow pigment carries its own light with it.

When flash gets in the way

In very clear, shallow water a sharp flash is visible from the same distance everything else is — the line, the angler’s shadow. There a matte surface gives less reason to spook the fish, while the same channel still works.

Flash doesn’t replace colour

These are two different channels of the same eye: colour reads up close and in the light, flash is noticeable from afar and shows itself. A mirror lure with no colour works, and a coloured lure with no flash works too — only one of them switches off at a time, never both.