Quick answer
A Datograph Up/Down copy is worth its price only when three things hold up: a chronograph that starts, stops, and flies back cleanly; a big date where both discs snap over together at midnight; and a case that measures close to the original 41 mm across and about 13 mm thick. If any of those three fail, the watch is a decoration, not a copy.
Datograph Up/Down Review: 1:1 Replica Comparison
What the Up/Down name means
The original A. Lange & Sohne Datograph Up/Down carries a power-reserve display on the dial, which is what the Up/Down label refers to. On a copy, that display is the first thing that separates a serious build from a cheap one, because a working reserve indicator needs a real gear train behind it. A painted or frozen needle is a giveaway.
Movement: the part that decides everything
The genuine watch runs a manual-wind column-wheel chronograph with a flyback function and roughly 60 hours of reserve. Copies almost never match that, and most fall into one of two groups: a modified Seagull or similar manual chronograph, or a quartz build hidden behind a decorated plate. Manual chronograph copies cost more and behave better. Quartz builds tick at the subdial and reset with a snap that feels mechanical, so always ask for a running video before you commit.
Case, crystal, and dimensions
The original is 41 mm wide in platinum, which makes it heavy. A steel copy will feel light in the hand, and that weight gap is normal. What is not normal is a case that measures 43 mm or sits 15 mm tall, because the proportions will look wrong on the wrist. Check the lugs, the bevel edges, and the mix of brushed and polished surfaces. The crystal should be sapphire with anti-reflective coating and no milky halo under light.
Dial and big-date checks
Look at the dial printing with a loupe or a phone macro lens. Genuine printing is crisp at the edges, with no bleed and no uneven spacing between the numerals. The big date uses two separate discs, and the joints between them should sit level. On weak copies one disc lags behind the other, or a thin sliver of the next number shows through the window during the day.
Before you start
- A loupe or a phone with a macro mode
- Digital calipers
- A video from the seller showing the chronograph running
- A written return window of at least seven days
Inspection checklist
- Ask for a video that shows the chronograph starting, stopping, and performing a flyback reset.
- Confirm the chronograph seconds hand returns to twelve and stays there.
- Wind the crown fully and watch the power-reserve hand travel across its whole scale.
- Set the time to 11:59 pm and confirm both date discs roll over at the same moment.
- Measure the case across the bezel; expect close to 41 mm.
- Measure the thickness from caseback to crystal top; expect roughly 13 mm.
- Press each pusher and note the travel; both should feel firm and even.
- Inspect the dial print, the hour markers, and the hand finish under magnification.
- Turn the watch over and read the caseback engraving for depth and clean edges.
- Check the strap stitching and the buckle engraving before you accept delivery.
Red flags
- Date discs that change at different times
- A chronograph reset that lands off zero
- A crown that grinds or wobbles when winding
- Printing that bleeds into the dial surface
- A seller who claims a platinum case at a steel price
- Refusal to send a live video of the watch running