A time delay integration (TDI) sensor (22) comprises a sequence of cells (42, 44, 42, 44) numbered 1 to N. The TDI sensor is configured for transferring a charge from the cell numbered 1 via the cells numbered 2 to N−1 to the cell numbered N. Each cell (42; 44) in the sequence of cells is either sensitive or insensitive in the sense that when the TDI sensor (22) is evenly illuminated by light (46) having a first spectrum, the intensity of the light (46) incident on any of the insensitive cells (44) is at most 90% of the intensity of the light (46) incident on any of the sensitive cells (42). The sequence of cells (42, 44, 42, 44) comprises, in this order: a first sensitive cell (42), at least one insensitive cell (44), and a second sensitive cell (42). An imaging system comprising a TDI sensor and a method of imaging an object are also disclosed.