Max Exposure per Line calculator
Each row's photon-collection window is bounded above by the time between consecutive line readouts — the row period (1 ÷ line rate). Exposure-budget class: tight.
How this is calculated
A linescan camera reads one row of pixels at every readout event — and the maximum integration time the camera can spend collecting photons for that row is exactly one row period: 1 ÷ line rate.
Pick a line rate, and the max exposure per line reads as 1 ÷ f_line — the per-row ceiling, in microseconds. Higher rates compress the exposure budget linearly: double the line rate and you halve the window. That budget is what dictates how hard you have to light the part.
The idea is simple: a linescan camera reads one row of pixels at each readout, and readouts come at a fixed rate. The gap between them — 1 ÷ line rate — is the longest a row can integrate. Go past it and one row's exposure runs into the next row's readout, mixing photons from two intervals and corrupting the image. In practice you often expose less than the max (to freeze motion or gate a strobe), but this is the hard ceiling.
That budget is the centre of linescan lighting strategy. At the default 50 kHz it lands at 20 μs — the standard production register where a high-flux LED bar gives adequate SNR. It shrinks linearly with line rate: 100 kHz → 10 μs, 200 kHz → 5 μs (where you need halogen or strobe-synced LEDs); slower 1–10 kHz lines open up to 100 μs and beyond, where ordinary LED light is plenty. Below ~2 μs (≥ 500 kHz) single-stage SNR runs out and TDI takes over.