Head-to-Head Comparison

Casio MTP-S120L Solar Field vs Orient Bambino Open Heart

Casio's field watch meets Orient's timepiece

Quick Verdict

The Casio MTP-S120L Solar Field ($100–$150) offers Casio Tough Solar Quartz precision in the tier below the Orient Bambino Open Heart ($250–$500). The MTP-S120L Solar Field measures 44.5mm and is rated 100m (10 ATM). The Bambino Open Heart counters with Japanese Movement craftsmanship and 30m (3 ATM) water resistance. Both are exceptional watches for their respective tiers.

CasioMTP-S120L Solar Field$100–$150 Check price OrientBambino Open Heart$250–$500 Check price

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Casio

MTP-S120L Solar Field

$100–$150

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Orient

Bambino Open Heart

$250–$500

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Specifications Compared

Feature	Casio MTP-S120L Solar Field	Orient Bambino Open Heart
Price	$100–$150	$250–$500
Case Size	44.5mm	40.5mm
Movement	Solar-Powered Quartz	Automatic Caliber F6T22
Caliber Type	Casio Tough Solar Quartz	Orient In-House Automatic, hand-winding and hacking
Power Reserve	Months on a full solar charge; no battery replacement	40 Hours
Water Resistance	100m (10 ATM)	30m (3 ATM)
Crystal	Mineral Crystal	Domed Mineral Crystal
Case Material	Stainless Steel	Stainless Steel
Origin	Casio (Japan)	Japanese Movement

Category-by-Category Analysis

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Design & Aesthetics

Edge: Draw

Casio's design language vs Orient's approach

The Casio MTP-S120L Solar Field features a Stainless Steel case at 44.5mm with Mineral Crystal protection. The Orient Bambino Open Heart offers Stainless Steel construction at 40.5mm with Domed Mineral Crystal. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Orient

Solar-Powered Quartz vs Automatic Caliber F6T22

The MTP-S120L Solar Field runs the Solar-Powered Quartz (Casio Tough Solar Quartz, Months on a full solar charge; no battery replacement power reserve) at standard frequency. The Bambino Open Heart uses the Automatic Caliber F6T22 (Orient In-House Automatic, hand-winding and hacking, 40 Hours reserve) at 21,600 vph (3 Hz). The Bambino Open Heart offers a longer power reserve.

📏

Wearability & Fit

Edge: Orient

44.5mm vs 40.5mm — different wrist presence

At 44.5mm, the MTP-S120L Solar Field has a bolder wrist presence compared to the Bambino Open Heart at 40.5mm. Water resistance differs: 100m (10 ATM) vs 30m (3 ATM).

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Value & Cost of Ownership

Edge: Casio

Casio sits in the lower tier

The Casio MTP-S120L Solar Field sits at $100–$150 and the Orient Bambino Open Heart at $250–$500. On the specs that outlast any price: the MTP-S120L Solar Field uses Mineral Crystal with Months on a full solar charge; no battery replacement, against Domed Mineral Crystal and 40 Hours on the Bambino Open Heart. Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Casio

100m (10 ATM) vs 30m (3 ATM)

The MTP-S120L Solar Field is rated to 100m (10 ATM) while the Bambino Open Heart handles 30m (3 ATM). The MTP-S120L Solar Field is better suited for water activities.

Our Verdict

Casio

MTP-S120L Solar Field

Choose the Casio MTP-S120L Solar Field if you prioritize Casio Tough Solar Quartz engineering, Casio (Japan) craftsmanship, and 100m (10 ATM) water resistance. At $100–$150, it delivers Solar-Powered Quartz with Months on a full solar charge; no battery replacement power reserve.

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Orient

Bambino Open Heart

Choose the Orient Bambino Open Heart if you value Orient In-House Automatic, hand-winding and hacking technology, Japanese Movement heritage, and 40.5mm proportions. At $250–$500, the Automatic Caliber F6T22 with 40 Hours power reserve makes it a compelling choice.

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The Bottom Line

The Casio MTP-S120L Solar Field and Orient Bambino Open Heart represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) tradition while Orient delivers Japanese Movement engineering.

Frequently Asked Questions

Neither is objectively better — they serve different preferences. The Casio MTP-S120L Solar Field ($100–$150) offers Solar-Powered Quartz with Months on a full solar charge; no battery replacement power reserve, while the Orient Bambino Open Heart ($250–$500) features Automatic Caliber F6T22 with 30m (3 ATM) water resistance. Choose based on your priorities: Casio (Japan) craftsmanship vs Japanese Movement engineering.

The Casio MTP-S120L Solar Field offers better upfront value, sitting a tier lower at $100–$150. However, the Orient Bambino Open Heart may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The MTP-S120L Solar Field at 44.5mm with 100m (10 ATM) water resistance handles everyday situations. The Bambino Open Heart at 40.5mm with 30m (3 ATM) is similarly capable. The MTP-S120L Solar Field uses Mineral Crystal while the Bambino Open Heart uses Domed Mineral Crystal.

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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.