The A. Lange & Söhne Datograph

A Deep Dive Into The World’s Best Mechanical Chronograph

If you’ve ever attended a watch collector GTG or spent any time on the various online watch forums you have most definitely heard mention made of the mythical A. Lange & Söhne Datograph, considered by many to be the best mechanical chronograph. Ever.

Introduced in 1999, the Datograph (date + chronograph) was the first, completely new, in-house mechanical chronograph produced in the last quarter of the 20th century, incorporating a fly-back function and precisely jumping minutes counter. It also featured a quick-set outsized date, and two irregularly placed reversed panda sub-dials – an attractive aesthetic that has since become a signature of the model.


You may be wondering to yourself, however, why a reference that’s almost 20 years old is still setting the benchmark for a segment of the luxury watch market that has grown increasingly popular in recent years, with many new competing models introduced.The simple answer is: it’s complicated. Depending on who you speak to, part of the reason relates to the context in which the Datograph entered the watch industry – it was a total game-changer the time.It firmly re-established Ferdinand A. Lange’s vision for German-made mechanical watches that could compete on level terms with the best in the world. At the end of the day, however, the longevity of the Datograph’s dominance comes down to the art of watchmaking itself.

The Datograph combines everything that is the very best of German watchmaking into one wristwatch – it embodies what every purist watchmaker aspires to (it’s a modern-day version of an F.A. Lange or Richard Lange-calibre mechanical watch), presented in impeccable Saxon manufacture tradition, offering unparalleled quality and finishing.

Respect for the Datograph – Redefining the Chronograph segment


"It took more than 150 years before either of Patek Philippe or Vacheron Constantin produced their own in-house manual-winding chronographs, and Audemars Piguet still does not have a strict in-house chronograph"

The Datograph is the wristwatch responsible for establishing the trend towards in-house designed and manufactured chronograph movements. Although comparatively accessible from a price point of view, chronographs are actually one of the most complex movements to manufacture and assemble- surpassing the complexity of tourbillons and even perpetual calendars (and that’s before adding in the Datograph’s flyback, instantaneous jumping minute counter and date complications).

Of vital importance, A. Lange & Söhne followed high horology’s cardinal rule that manually wound chronographs are superior to their automatic counterparts due to their constant power supply and direct transmission of that power to the chronograph function.

Investing in such a calibre, that at the time did not represent a large portion of the market, was simply not the done thing. It took more than 150 years before either of Patek Philippe or Vacheron Constantin produced their own in-house manual-winding chronographs, and Audemars Piguet still does not have a strict in-house chronograph (without tourbillon).

Watch manufacturers relied on outsourced, standardised movements – for example, a year prior to the Datograph’s debut, Patek Philippe released a chronograph, reference 5070, which used a heavily-modified Lemania-based movement.


The important thing to note here, other than the obvious, is that these proven movements were decades old. When the Datograph hit Baselworld in 1999, it was not just the debut of an in-house calibre – it was the first in-house chronograph built from the ground up in 20 years.

Of itself, this was a tremendous achievement for the fledgling company, which just 5 years prior had introduced the first creations of the new A. Lange & Söhne era. That Germany was still in the wake, and political and economic turmoil, of reunification – makes the accomplishment that much more astonishing. Consider, it took Patek Philippe 11 years to respond with its own manually wound chronograph, reference 5170J, to compete in the same price range. The Vacheron Constantin Harmony Chronograph did not arrive until 2015.

However, it’s not just the achievement of producing a new chronograph that set the Datograph apart – it was the complexity and level of craftsmanship of this (serially produced) timepiece. It was the type of chronograph A. Lange & Söhne chose to build, and how they built it, matched with a perfectly balanced dial and case crafted to the uppermost standards possible, that forged the Datograph’s ‘grail’ status. The Datograph demanded respect, placing the German brand from Glashütte firmly among its peers from the elite holy trinity(or big 3) of watchmaking, making many people sit up and take notice in the process.

German Flair


"The multi-level calibre gave an awe-inspiring three-dimensional vista of mechanical components packed together with the sort of precision that allows one to close a heavy bank vault door with the tip of a finger"

The last flourishing of German watchmaking prior to WWII, and the events that led to A. Lange & Söhne’s hiatus, was the dying pocket watch age. The Lange dynasty, starting with Ferdinand A. Lange, had earnt an international reputation for its prized pocket watches. The Datograph’s design drew heavily on this tradition, most notably in the classic column wheel chronograph – which made for a far more complicated movement due to the multi-plain architecture. Mainstream manufacturers tend to avoid this style due to its complexity and increased case thickness, and because (in exposed case backs) many more surfaces and edges are visible and hence require finishing.

All of this, however, played into the vision for the Datograph, which was to create a timepiece that was both a visual and tactile banquet for the senses.

The multi-level calibre gave an awe-inspiring three-dimensional vista of mechanical components packed together with the sort of precision that allows one to close a heavy bank vault door with the tip of a finger – experienced through the ultra-smooth pushers and solid crown and winding mechanism, all of which provided just the right level of feedback when actuated. Where the Datograph really shone though, was in the level of finishing of every one of those components. The finishing on the Datograph is so high it is unrivalled by even most independent watchmakers, and carries the approval of Vallée de Jouxicon, Philippe Dufour.

This attention to detail extended to the rest of the wristwatch’s construction, demonstrating a strong continuity. Before even turning the wristwatch over to view the main event, the A. Lange & Söhne Datograph makes a striking statement from the front that leaves a lasting impression.

The ‘Tuxedo’ of A. Lange & Söhne

Working inwards, the Datograph was born with a black, alligator leather strap (a bracelet was also available)/ a white metal case/ and a glossed black (solid silver) dial, with highlights. Black dial timepieces from A. Lange & Söhne are considered something of a rarity, and the Datograph was the first. The Datograph has always worn its outsized date (a signature of modern German watchmaking) like a bowtie at 12 o’clock. From there, symmetry radiated out in all directions.


The reversed panda sub-dials were lowered to balance with the date windows, the II, VI and X Roman numerals a mirror opposite, and the remaining full bar markers at 1, 5, 7 and 11 o’clock again reflected a perfect symmetry between the upper and lower halves of the dial. Applied hour markers were fashioned from white gold, while a painted white tachymeter scale added another layer of sophistication, and rhodiumed gold hour and minute alpha hands received sufficient Super-LumiNova to make the deal of the Datograph legible at night.

In the typical German way of manufacturing timepieces, nothing was superfluous. The understated tuxedo style of black and white preparing one’s palate for the multi-coloured spectacle that lay beneath.

The Main Event

In-House Manufacture Calibre L951.1

The Calibre L951.1 surpassed mere functional engineering – it was designed to inspire awe. The 12.8mm case thickness was purposefully chosen to allow depth in the movement’s 405-component architecture, which many have referred to as resembling a mini-metropolis – the more you look, the more you find to look at. This multilevel configuration is rivalled only by the movements of the A. Lange & Söhne Double Split and Triple Split – while it could be argued these models outperform their older brother, the Datograph holds its place as the ultimate chronograph in the purist sense.

Engineering-wise, the manual-winding L951.1 employed traditional watchmaking practices, rarely seen (because it’s so hard to do). The shock protected screw balance ran slow at 18,000vph to enhance the power reserve (36 hours). While the larger gears accomplished higher reliability at greater efficiency. The additional fly-back* and precisely jumping minute counter* complications were also technology from the first half of the century, not seen in high-end chronographs.

One deviation from traditional German watchmaking (rare for A. Lange & Söhne) was the absence of a 3/4 plate, which would have obstructed the view. Instead, a composite of plates, made to mimic the 3/4, was buried beneath the main event. Thus, the chronograph and flyback functions are clearly visible in action through the exposed back.

Every part of the L951.1 calibre was hand finished. Each lever bevelled and straight grain polished. The balance cock hand-engraved. Each screw head, the swan’s neck regulator, the plate over the escape wheel, and the caps of each chronograph wheel column black polished. Of the 40 jewels used to reduce mechanical friction to a minimum, four were set in gold chatons (an old pocket watch assembly tradition, again, not easy to do). The bridges and buried composite of plates, adorned with Glashütte ribbing, were of course made from untreated German silver, which only improves with age (gaining a golden patina).

But the attention to detail didn’t stop there.

Details Count

Turn the watch back over and take another look at the sub-dials (which used blued steel hands for clarity) – they too were fashioned from German silver (creating a connection between the dial and movement). The offset reversed panda sub-dials accentuated the dial’s pocket watch character, and gave the Datograph away at a distance, capable of catching an observer’s attention from across the room.

The case back, bezel and lugs were mirror polished, while the middle case was straight grain polished (again echoing the movement). Set within this middle case, the pushers were made of white gold, like the applied hour markers and time hands. The platinum pin buckle matched the case material.

On The Wrist

Finally, we come to how the Datograph actually looks and feels on the wrist. With its perfect proportions and gently sloping lugs, the 39mm case comfortably hugs your wrist (when you’re not taking it off to admire the movement). Constructed from gold or platinum, the extra thickness that housed the ‘beast’ had a nice weight to it but not enough to make it feel cumbersome on the wrist.

A Moment for Reflection

In summary, the Datograph was – and still is- a harmonious symphony of sheer brilliance and unrivalled craftsmanship that cradles the traditional heritage of watchmaking while at the same time pushing the envelope in terms of contemporary innovation.

The wow factor of the Datograph reflects the enormous amount of thought that went into conceiving it, and perhaps – when one considers the backstory of A. Lange & Söhne – therein lies the most overlooked aspect of the Datograph’s success (Walter Lange had until his 60s to think about it conceptually). That pondering created the Datograph, as a debuting piece of innovation, virtually faultless. So, while some have managed the feat of an in-house movement, there’s still nothing that compares outside of the A. Lange & Söhne folds (although Jaeger-LeCoultre, a Richemont Group cousin, has mounted the beginnings of a challenge with the Duomètre à chronographe).

Datograph Auf/ Ab

After an unprecedented production run of 12 years, the Datograph was upgraded to the Datograph Up/ Down, released prior to SIHH 2012. The new version increased the case diameter to 41mm (while maintaining the original’s proportions) and introduced a discrete power reserve indicator at 6 o’clock – quite useful for a manual-winder. A larger mainspring barrel permitted an increased power reserve of 60 hours. In line with the updated Saxonia design aesthetics, the Datograph Up/ Down dropped the remaining Romain numerals (in the upper half of the dial). Outside of these changes, the modern-day Datograph Up/ Down remains quite true to the original.

The larger, sleeker Datograph Up/ Down has a slightly more modern look and feel. It’s available in platinum or pink gold (with a brown strap).


A closing note on the world’s best chronographs

Don’t walk away with the notion that in-house chronographs are automatically superior. It still comes down to the calibre of the calibre. The cottage industry approach, where each company specialises in specific parts of the watch – which F.A. Lange promoted – has its merits. The L951.1 was/ and is an exceptional chronograph. As an in-house movement, it threw down the gauntlet to other watch manufacturers – none of which have yet managed to surpass the pinnacle of the A. Lange & Söhne Datograph.

Watches of Switzerland is the exclusive retailer of A. Lange & Söhne in Australia. View the collection here.

Photos by H.M Wang and A. Lange & Söhne

  1. Precisely jumping minute counter: primarily used in pocket watches, the mechanism records each full revolution of the chronograph seconds hand – making it easier to read elapsed time, when the chronograph is stopped (the precisely jumping minute counter used in the Datograph improved on earlier designs and A. Lange & Söhne was granted a patent for an adjustable operating lever);
  2. Flyback function: originated from early aviation models, allows one to stop/ reset/ and restart the chronograph in a single operation (by pressing and releasing the pusher at 4 o’clock) during rapid successive measurements.