One of the most common questions we get on the Speedmaster concerns the Speedmaster Reduced (reference 3510.50). What is the difference between the Speedmaster Professional and this “Reduced” version? If you’re a veteran Speedy enthusiast, this won’t be news to you, but as it keeps popping up, we must answer the call. Especially with the popularity of the Speedmaster today, the demand for the Reduced has increased. Let us help make you aware of the critical differences.


Image source: LOVE AND FUN PRODUCTION UG (via Chrono24).

Moonwatch versus Reduced

This discontinued Speedmaster is often mistaken for the popular Speedmaster Professional Moonwatch. If you are not that deeply into Speedmasters and just like the look of the black no-date dial with three registers at 3, 6, and 9 o’clock, it is easy to mistake the Reduced for a Moonwatch.

Speedmaster Moonwatch vs Reduced

Omega Speedmaster 3510.50

The Omega Speedmaster Reduced is a very nice watch. However, like the Dark Side of the Moon or the Speedmaster ’57, it is not a Moonwatch. And that is despite the fact that even Omega used to label some of these models as such. Thankfully, that’s not the case anymore.

In the comparison pictures in this article, you can find the Speedmaster Professional Moonwatch on a NATO strap and the Speedmaster Reduced on a stainless steel bracelet. The most obvious differences are, of course, the size of the watch and the “Professional” printing that can only be found on the Moonwatch. Below, you can also see the Speedmaster Professional Moonwatch on a bracelet.

A Speedmaster Professional Moonwatch

Their appearances are similar, but when you look at them side by side, you will find some important differences between the two.


First of all, the sizes of the watches differ. While the Speedmaster Professional measures 42mm in diameter, the Speedy Reduced is smaller at just 38.5mm. The Omega website states 39mm, but watch brands often round up or down.

Speedmaster Moonwatch vs Speedmaster Reduced

Movement — Automatic versus Manual

The movement is also quite different. This explains the difference in the dial layout as well. As you can see in the pictures, the sub-dials are quite far away from the center on the Speedy Reduced, while the sub-dials on the Moonwatch are closer to the center pinion. The Speedmaster Reduced also has the “Automatic” wording on its dial and features the minutes in Arabic numerals at each hour marker. Below is an image of the hand-wound movement inside the current Speedmaster Professional, caliber 3861.

Speedmaster Professional with caliber 3861

The Speedmaster Professional movement is a hand-wound Lemania-based chronograph, either caliber 321, 861/863, 1861/1863, or 3861 (depending on the age of the watch). The Speedy Reduced has an automatic movement based on the no-date ETA 2890-A2, also known as the Omega caliber 3220. Mounted to the dial side of the base movement is a Dubois-Dépraz 2020 chronograph module.

Caliber 3220 (picture via

A piggyback movement with a lot of jewels

The add-on module also explains this movement’s high 47-jewel count. These so-called “piggyback movements” are easy to identify by looking at the watch from the side. The winding crown and chronograph pushers are not aligned. The crown is positioned a bit lower, as shown in the picture below.

Speedmaster Reduced vs Speedmaster Moonwatch

Don’t be fooled (but it is a great watch)

In the end, there is absolutely nothing wrong with an Omega Speedmaster Reduced. If you prefer automatic movements, have a small wrist, or just have a tighter budget, the Speedy Reduced 3510.50 can be the way to go. However, if you’re looking specifically for a Moonwatch, don’t be fooled by classifieds or ads on websites that use the word “Moonwatch” in combination with the Speedmaster Reduced 3510.50. Sometimes, the price is very interesting on these pre-owned Speedy Reduced models. If you don’t do your homework properly, you can easily be deceived or misled by the seller. So, not a bad word about the Speedmaster Reduced from our side, but make sure you end up with what you want.

The Speedmaster Reduced we featured in this Wrist Game Or Crying Shame article. Image source: LOVE AND FUN PRODUCTION UG (via Chrono24).

Price of the Omega Speedmaster Reduced

Unfortunately, the Speedmaster Reduced isn’t as big of a bargain as it was a few years ago. These days, the Omega Speedmaster Reduced starts at around €2,500. If you want the box and papers included, be prepared to pay more. And while there are loads of excellent Speedy Reduced examples coming out of Japan, be mindful of additional import duties charged on top of the sale price. Another interesting thing is that some very nice variations of the Speedmaster Reduced are worth checking out. A pre-owned Moonwatch (311., 3570.50, 3590.50 or 145.0022, etc.) will be more expensive, starting at around €4,500 for one in nice condition.

Moonwatch Master Chronometer

The current Omega Speedmaster Professional Moonwatch Master Chronometer

But if you want the real deal…

Note that the current Speedmaster Professional (here’s an article on how it became the Moonwatch) goes by the reference 310. Earlier references are 311., 3570.50, 3590.50, 145.022, 145.012, 105.012, 105.003, 105.002, CK2998 and CK2915. Some limited or special editions occasionally have a slightly different reference number, so be mindful of that. You will find an overview of all these Moonwatch references in this article.

You can find all of our Speedy Tuesday articles here.

This article was first published on June 25th, 2013. It has been updated with new pictures, prices, and information.