When the far surface is dark, glossy, angled or absent, and outdoors in bright light where the returning spot competes with sunlight. A rigid pale or retro-reflective plate returns far more signal, restoring range and accuracy. It is often the difference between an unreliable reading and no reading at all.

No - they only make the laser spot easier to see, which helps you aim in daylight. The measurement itself is unaffected. They are genuinely useful for long outdoor shots where the spot is otherwise invisible, but they should not be expected to change the reading.

To remove hand shake, which matters increasingly with distance because a small angular error becomes a large linear one at range. It is effectively required for accurate indirect height measurement, where the instrument's own tilt forms part of the calculation and any movement corrupts the result.

Placing the measurement reference point where the instrument body will not fit - into an internal corner, over an edge, or into a recess. They work with the meter's reference-point setting, and a mismatch between the adapter used and the setting selected offsets every reading by a fixed amount.

Tripod threads are largely standard, so mounting hardware often crosses brands. Target plates are generally universal. Corner and extension adapters, and anything that changes the reference point, are usually instrument-specific because the offset has to match what the meter expects.

Keeping the lens and detector windows clean, since dust and fingerprints scatter both the outgoing and returning beam and quietly reduce range; protecting it from drops, which can shift the internal alignment; and replacing batteries before they are flat, as low power affects range before it affects the display.

Measure a known distance - a calibrated tape run, or a fixed reference marked on site - at several ranges and compare. Discrepancy that grows with distance suggests an alignment problem; a constant offset usually means the reference-point setting or an adapter, which is far more common and easily corrected.