Head-to-Head Comparison

Updated September 5, 2026

Orient Sun & Moon vs Zenith Chronomaster El Primero Open Power Reserve (18k rose gold)

Orient's dress watch meets Zenith's chronograph

Quick Verdict

The Orient Sun & Moon ($250–$500) offers Orient In-House Automatic (Hacking, Hand-Winding) precision in the tier below the Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) ($10,000–$25,000). The Sun & Moon measures 41.5mm and is rated 50m (5 ATM). The Chronomaster El Primero Open Power Reserve (18k rose gold) counters with Swiss Made craftsmanship and 100m (10 ATM) water resistance. Both are exceptional watches for their respective tiers.

View the dossier ZenithChronomaster El Primero Open Power Reserve (18k rose gold)$10,000–$25,000 Check price

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Orient

Sun & Moon

$250–$500

View the dossier Full Review

Zenith

Chronomaster El Primero Open Power Reserve (18k rose gold)

$10,000–$25,000

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Specifications Compared

Feature	Orient Sun & Moon	Zenith Chronomaster El Primero Open Power Reserve (18k rose gold)
Price	$250–$500	$10,000–$25,000
Case Size	41.5mm	42mm
Movement	Automatic Caliber F6B24	Automatic chronograph, Zenith El Primero 4021
Caliber Type	Orient In-House Automatic (Hacking, Hand-Winding)	El Primero 4021, 36,000 vph (5 Hz), column wheel, automatic
Power Reserve	40 Hours	About 50 hours, with indicator
Water Resistance	50m (5 ATM)	100m (10 ATM)
Crystal	Mineral Glass	Sapphire Crystal, sapphire exhibition caseback
Case Material	Stainless Steel	18k rose gold
Origin	Made in Japan	Swiss Made

Category-by-Category Analysis

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Design & Aesthetics

Edge: Draw

Orient's design language vs Zenith's approach

The Orient Sun & Moon features a Stainless Steel case at 41.5mm with Mineral Glass protection. The Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) offers 18k rose gold construction at 42mm with Sapphire Crystal, sapphire exhibition caseback. Both represent their brand's distinct design philosophy and heritage.

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Movement & Performance

Edge: Zenith

Automatic Caliber F6B24 vs Automatic chronograph, Zenith El Primero 4021

The Sun & Moon runs the Automatic Caliber F6B24 (Orient In-House Automatic (Hacking, Hand-Winding), 40 Hours power reserve) at 21,600 vph (3 Hz) frequency. The Chronomaster El Primero Open Power Reserve (18k rose gold) uses the Automatic chronograph, Zenith El Primero 4021 (El Primero 4021, 36,000 vph (5 Hz), column wheel, automatic, About 50 hours, with indicator reserve) at standard. The Chronomaster El Primero Open Power Reserve (18k rose gold) offers a longer power reserve.

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Wearability & Fit

Edge: Orient

41.5mm vs 42mm — different wrist presence

At 41.5mm, the Sun & Moon wears more compactly on smaller wrists compared to the Chronomaster El Primero Open Power Reserve (18k rose gold) at 42mm. Water resistance differs: 50m (5 ATM) vs 100m (10 ATM).

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Value & Cost of Ownership

Edge: Orient

Orient sits in the lower tier

The Orient Sun & Moon sits at $250–$500 and the Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) at $10,000–$25,000. On the specs that outlast any price: the Sun & Moon uses Mineral Glass with 40 Hours, against Sapphire Crystal, sapphire exhibition caseback and About 50 hours, with indicator on the Chronomaster El Primero Open Power Reserve (18k rose gold). Service intervals are typically 5-7 years for both.

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Water Resistance

Edge: Zenith

50m (5 ATM) vs 100m (10 ATM)

The Sun & Moon is rated to 50m (5 ATM) while the Chronomaster El Primero Open Power Reserve (18k rose gold) handles 100m (10 ATM). The Chronomaster El Primero Open Power Reserve (18k rose gold) offers superior water resistance.

Our Verdict

Orient

Sun & Moon

Choose the Orient Sun & Moon if you prioritize Orient In-House Automatic (Hacking, Hand-Winding) engineering, Made in Japan craftsmanship, and 50m (5 ATM) water resistance. At $250–$500, it delivers Automatic Caliber F6B24 with 40 Hours power reserve.

View the dossier

Zenith

Chronomaster El Primero Open Power Reserve (18k rose gold)

Choose the Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) if you value El Primero 4021, 36,000 vph (5 Hz), column wheel, automatic technology, Swiss Made heritage, and 42mm proportions. At $10,000–$25,000, the Automatic chronograph, Zenith El Primero 4021 with About 50 hours, with indicator power reserve makes it a compelling choice.

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The Bottom Line

The Orient Sun & Moon and Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) represent two distinct approaches to fine watchmaking — the Orient bringing Made in Japan tradition while Zenith delivers Swiss Made engineering.

Frequently Asked Questions

For water, the Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) is rated 100 m against 50 m, which is the difference between swimming and diving on one side and splashes on the other. On price, the Orient Sun & Moon sits a band lower ($250–$500 against $10,000–$25,000), so it is the cheaper way into the category. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.

The Orient Sun & Moon offers better upfront value, sitting a tier lower at $250–$500. However, the Zenith Chronomaster El Primero Open Power Reserve (18k rose gold) may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The Sun & Moon at 41.5mm with 50m (5 ATM) water resistance handles everyday situations. The Chronomaster El Primero Open Power Reserve (18k rose gold) at 42mm with 100m (10 ATM) is similarly capable. The Sun & Moon uses Mineral Glass while the Chronomaster El Primero Open Power Reserve (18k rose gold) uses Sapphire Crystal, sapphire exhibition caseback. Sapphire resists scratches noticeably better than mineral glass.

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How This Page Was Made

Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.