Review: Longines Master Collection Moonphase L2.673


The outer box of the Longines Master Collection Moonphase

Long before I actually bought the Longines Master Collection Moonphase, I spent a many hours shopping around to see what would finish up the first “trio” of watches in my collection. My first watch, the Tag Heuer Aquaracer was more of a “beater” watch that I could wear casually and when outdoors. My second watch, the Maurice Lacroix Masterpiece Cinq Aiguilles, was the definition of a classy formal watch, with a simple face and black leather band. To round out the trio, I wanted something casual but also appropriate in semi-formal occasions. I also wanted a timepiece with a more complex face given the simple (but beautiful) faces on my first two watches.

Beautiful wooden box inside the outer box

The Longines Master Collection Moonphase fit those criteria perfectly. At $2,245, it was the most I’ve paid for a watch (almost as much as my previous two combined), but the more I looked around at comparables, the more I realized how much of a steal this watch was. It even came with a moonphase complication (among many other functions), something I’ve wanted on a watch since I first laid eyes on it. It also helped that Longines was a reputable and reliable brand (owned by the Swatch Group in its “high range” category of brands), although this also meant that I couldn’t get it for much less than retail; I paid only 32% off at an online grey market retailer compared to the ridiculous 74% off I got on my Maurice Lacroix. However, as you’ll see in this review, I’m more than happy with this timepiece and think it’s a great value.

Note: I will refer to the Longines Master Collection Moonphase as the LMCM for the rest of the post since it’s a lot shorter and makes writing about it much easier.


The beautiful front face of the LMCM

Despite the complexity of the LMCM’s dial, it still manages to look classy and not overly complicated or like it’s trying too hard. The barleycorn texture on the silver dial adds a sense of classic luxury to the watch, while on the other hand the Arabic numerals on all of the functions speak to more of a modern look. All eight (!) hands are blue steel, although none of them have any luminescence for viewing in the dark. This makes sense in my opinion; with a watch with such a complex face, it’d be very difficult to make out in the dark without the seeing the markers in the background.

There are several other notable features on the face of the LMCM. The moonphase function is beautiful with a golden moon on a blue-background disc that is highlighted by golden stars throughout. At the 3 o’clock position is the Longines logo that fits perfectly with the barleycorn texture. Lastly, the date indicator around the outer rim is shown by a crescent-tipped hand that selects the number of the date.

The back is transparent, showing the L678 movement

The back of the watch is nearly as complicated as the front. While the alligator leather band is colored a dark brown in the front, the back shows more of a lighter “tan” color that is etched with the Longines logo. The transparent back allows a full view of the complex L678 movement and is a snap-on back, which is the unfortunately main reason behind the LMCM’s low water resistance rating. The movement window is surrounded by text (perhaps a little too much) on the stainless steel case: “The Longines Master Collection” on the top and “stainless steel” + water resistance on the bottom.


This instruction book is thicker than this picture shows and contains instructions for every Longines watch

I thought it was a nice touch for Longines to include all of its watches’ instructions in one manual the box, and it was interesting to see that the LMCM was by far the most complex watch in the collection (see below). First, all of the “normal” watch functions are pretty straightforward for an automatic watch. The crown — with a pull/push mechanism — allows manual winding of the watch in the neutral position. In the second position, the LMCM is stopped and this allows precise setting of the minute hand. In terms of function, the minute and hour hands move in a standard way, while the time-keeping seconds hand is actually the small seconds hand at the 9 o’clock position, since the LMCM is a chronograph.

The instruction guide for the LMCM is on the last page and is by far the most complicated

What really makes the LMCM shine are the extra complications on the face of the watch. First, the 24 hour indicator is indicated by the larger hand in the 9 o’clock window, and this is tied to the main hour hand (cannot be manually adjusted) to indicate AM/PM. The date is shown by the long crescent-tipped hand, with markers around the outer rim. This is adjusted by turning the crown backwards in the first position, and adjusting this also adjust the month indicator accordingly on the right of the 12 o’clock window. Unfortunately, the LMCM does not have a perpetual or annual calendar, so manual adjustment of the date is required on months with fewer than 31 days, or five times a year.

Next to the month indicator is the day-of-week indicator, which is actually adjusted by a depressed button on the outer rim of the case at the 10 o’clock position by a tool that Longines provides (see picture below). At the 6 o’clock position is the moonphase indicator, which is also adjusted in the first position, except by turning the crown forwards. The moonphase is driven by a 59-tooth gear (so there are two full moons per full rotation of the disc), which is the most standard gear size that allows the moonphase have an error of +1 day per ~31 months. Lastly, the chronograph is pretty traditional, with the seconds hand as the main seconds hand, a 30-min indicator at 12 o’clock, and a 12-hour indicator at 6 o’clock on top of the moonphase. It’s operated by two push buttons on each side of the crown, with the “reset” button locked when the chronograph is running (no flyback function).


The L678 is gorgeously decorated

The Longines Calibre L678 movement is a modified ETA Valjoux 7751, which is a typical chronograph + moonphase movement used in the automatic watch industry. The movement vibrates at a standard 28,800 per hour with a 42-54 hour power reserve, depending on which website you ask. Since I have it on a watch winder, I have not tested this power reserve, but I’m sure it also varies depending on whether you are using the chronograph while the watch is running. On watch winders, the L678 movement is optimally set at 800 turns per day in the CW direction.

The LMCM’s movement is artfully decorated, as seen in the above photo. There are a plethora of gold-plated rotors and gears while a large portion of the surface is decorated in perlage. The half circle rotor is etched with a high quality Côtes de Genève, and the Longines logo is actually cut out from it, allowing you to see what’s underneath as the rotor moves around.


As I mentioned in the intro, the LMCM is an absolute steal at its price. This is apparent since if you do a search on automatic watches from reputable brands that have both a chronograph and a moonphase complication, you’ll come up with nothing that’s lower in price. The closest competitor is the Baume et Mercier Clifton Chronograph at $3,395 (nearly 50% more), which has the same ETA Valjoux 7751 movement. In my opinion, the Clifton’s colors are more bland than the LMCM’s and the 43mm case is a little large for me. Next is the Montblanc Heritage Chronometrie Chronograph at $4,995, and with that price tag you’ll get a heavily in-house modified Sellita SW500 movement with an annual calendar function (only have to adjust date at the end of February). The subdials are also set up differently on the Montblanc compared to the LMCM, especially with the moonphase on a dial rather than a disc display. Lastly, for a whopping $6,499, you can get the Zenith El Primero 410 Complete Calendar Moonphase. While it doesn’t have the annual calendar of the lower-priced Montblanc, the El Primero comes with Zenith’s world-renowned El Primero 410 in-house movement, a 31-jewel mechanical marvel that vibrates at 36,000 per hour (10 per second).


The LMCM was surprisingly easy to set up for the first time

Setting up the LMCM was actually much easier than expected. The single-page instruction manual was perfectly clear and it’s pretty incredible that Longines was able to fit the vast majority of the function adjustments on just two crown positions. To set up the moonphase, I found the most recent full moon and adjusted the disc forward while counting the days. For example, if today is 3/7/2018, then the last full moon was 3/2/2018. I would set the moonphase disc such that the moon is perfectly centered on the display, and then adjust it five days forward.

For me, the triple safety clasp on the LMCM’s watch strap actually took more getting used to than the watch itself. It’s actually a two step process to close the clasp, since both sides hook into the push button clasp. However, my hand is large enough that I have to unclasp both sides in order to put on the watch, so I imagine for those who have a higher wrist-to-hand size ratio, it may be possible to leave the “smaller” side always clasped to make the process easier. In terms of ease of use, the chronograph works as expected, although I found the amount of force I had to use to push both the start/stop and reset buttons a little unsettling at first, especially since the buttons feel a little flimsy when you press them down (rather than a nice clean click). In addition, the LMCM is fairly easy to read, with my only two small gripes being that the 12-hour chronograph indicator on top of the moonphase is hard to see since both the hand and the moonphase disc are blue, and that the timekeeping seconds hand on the 9 o’clock subdial is a little small for my taste

In my first month of using this watch, I’ve been getting a consistent +7 seconds/day error on the L678 movement on the LMCM, regardless of whether it’s on my watch winder or on my wrist. Given this precision of this error, I plan to get it adjusted by a watch shop to improve the accuracy. Another quirk I noticed with the movement is that the half-circle rotor moves much more freely than the ones on any of my previous watches (i.e. the circular friction on the rotor is much lower). In fact, if you “shake” the watch in a circular motion, it’s possible to get the rotor to spin a dozen times before it stops. One more note is that I can actually clearly feel the rotation of the rotor when the watch is on my wrist. I’ve been informed that this is known as “wobble” and is common to many movements with uni-directional winding like the ETA Valjoux 7751. The rotor freely spins in the direction that it doesn’t wind in, causing the effect that I’m feeling.


Overall, the Longines Master Collection Moonphase did not disappoint


  • Unbeatable price for an automatic chronograph moonphase watch
  • Strong and reputable Longines brand
  • Classic hybrid (classic and modern) look that works with the complex dial


  • Even at its low relative price to its competitors, $2,245 is a lot to spend on a watch for most people


Manufacturer: Longines
Model: L2.673.4.78.3
Functions: Month, date, day, hour, minute, second, chronograph, moonphase, 24-hour
Movement: Longines Calibre L678, automatic, 28,800 vph, 25 jewels, 48 hour power reserve
Case: Stainless steel case with transparent case back, sapphire crystal, water resistant to 30 meters
Band: Brown alligator leather strap, width = 19 mm, triple safety folding clasp with push-piece opening mechanism
Dial: Silver “barleycorn”, painted Arabic numerals, blue steel hands, pull/push crown, date scale around outer rim, minute markers around inner bezel
Dimensions: Diameter = 40 mm, thickness = 14mm
Variations: Black dial w/silver hands, rose gold case, stainless steel bracelet
Price: $2,245 (purchased), $2,295 (current Jomashop grey market), $3,325 (Retail)

3 thoughts on “Review: Longines Master Collection Moonphase L2.673

  1. Why do all moon-phase watches have a garish blue and yellow colour for the moon part? To me that spoils the overall look of the watch face. I’d be happy if it was just black and silver, or a tasteful grey colour.


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