Complication guide
Chronograph: how the complication works
A chronograph is a watch with a built-in stopwatch, started, stopped and reset by pushers while the watch keeps telling the time.
A chronograph adds a stopwatch to a normal watch. The main hands keep time as always, while a separate set of hands, driven through a clutch and a column wheel or a cam, can be started and stopped to measure an interval and then zeroed.
The mechanism makes a chronograph movement thicker and more complex than a plain time-and-date caliber, which is why a chronograph rarely drops straight into a case built for a simple three-hand movement. The Valjoux 7750 in particular has a distinctive layout with the sub-dials at 6, 9 and 12, and is one of the most widely used automatic chronograph calibers.
Related complications and calibers
Automatic windingAn automatic, or self-winding, movement winds its own mainspring from
Date and day-dateA date complication shows the calendar date through an aperture; a day
GMT and second time zoneA GMT watch shows a second time zone on an extra hand that circles the
MoonphaseA moonphase complication shows the current phase of the moon through a
ETA Valjoux 7750caliber and drop-in group
Sellita SW510caliber and drop-in group
All complications and typesBrowse every guide