BRONICA ETRSI

Name: Bronica ETRSi
Brand: Bronica

The Bronica ETRSi is a 6×4.5cm medium format single-lens reflex (SLR) camera made by the Japanese manufacturer Zenza Bronica from 1984 to 1995. It is an advanced version of the earlier ETR series, with improved electronics, TTL (Through-The-Lens) flash metering and better reliability. It was a compact, capable modular system for professionals and advanced amateurs who wanted high image quality.

Overview

Bronica released the ETRSi in 1984 as a refinement of the successful ETR and ETRs models. It addressed user feedback and added advances in electronic control. It belongs to Bronica's line of modular medium format SLRs, where film backs, viewfinders and lenses all swap out. The body stayed relatively compact and light next to larger 6×6 or 6×7 systems. The ETRSi was built for the 6×4.5cm format, which gives ten exposures per standard 120 roll film. That balances image size against shooting efficiency, and suited photojournalism, event photography and travel.

The ETRSi kept the core mechanical design of its predecessors and added significant electronic upgrades. The biggest one: it was the first in the ETR series with TTL flash metering. That gives accurate automatic flash exposure with compatible dedicated flash units such as the Bronica Auto Flash ETR, or with external TTL-capable strobes. Studio and on-location photographers who wanted precise flash control without manual calculations took to it. The camera also has a redesigned circuit board and improved battery efficiency, which helped reliability in varied environmental conditions.

In Bronica's lineup, the ETRSi sat in the middle, between the simpler SQ series and the more advanced GS-1. It shared lens compatibility with the earlier ETR models through the Bronica E mount, but its electronic integration was better. It is not a big camera, yet it supported a full suite of professional accessories: multiple focusing screens, interchangeable winders, polarizing prisms and data backs. It came out while Hasselblad, Mamiya and Pentax were competing hard in medium format SLRs, and it stood out on affordability, modularity and ease of use.

Specifications

Specification	Value
Type	Single-Lens Reflex (SLR)
Film Format	6×4.5cm (120 roll film)
Years Produced	1984–1995
Lens Mount	Bronica E Mount
Shutter	Focal-plane cloth shutter; 1 sec to 1/1000 sec, B, X-sync at 1/60 sec
Metering	TTL open-aperture center-weighted metering via CdS cell
Exposure Modes	Manual exposure only; stop-down metering via AE Coupling Pin
Viewfinder	Interchangeable pentaprism and waist-level finders; standard prism with split-image rangefinder and microprism collar
Dimensions	105 mm (W) × 95 mm (H) × 100 mm (D); approx. 790 g (body only, no battery)

Key Features

TTL Flash Metering: First in the ETR line to support through-the-lens flash automation, allowing precise exposure with dedicated flash units.
Modular Design: Fully interchangeable film backs, viewfinders, and focusing screens enable rapid film type switching and customization.
Electronic Shutter Control: Microprocessor-controlled shutter with improved accuracy and consistency across all speeds.
Stop-Down Metering with AE Coupling: Enables accurate exposure with lenses of varying maximum apertures via mechanical linkage.
Compact 6×4.5 Format: Offers 10 exposures per 120 roll film with minimal bulk, ideal for extended shooting sessions.

Historical Context

The ETRSi arrived when medium format was moving from fully mechanical systems to electronically augmented designs. It competed mainly with the Mamiya C330 and Pentax 6×7, and more directly with the Hasselblad 2000FC and later 203FE. Its niche was a cost-effective, modular system with modern electronic features. The 6×4.5cm format is a practical compromise between the square 6×6 frame and larger formats, for photographers who wanted portability without giving up resolution.

Reception was generally positive, especially among wedding photographers, photojournalists and studio shooters who valued the camera's reliability and TTL flash capability. It cost less than Hasselblad systems, which made it a popular choice in rental fleets and educational institutions. By the early 1990s, competition from Mamiya's 645 series, particularly the Mamiya 645AF, began to eat into Bronica's market share. The ETRSi stayed in production until 1995, over a decade longer than the original ETR.

Collectibility & Value

Today the ETRSi is considered a capable and collectible medium format SLR. Analog photography enthusiasts like it, as do people looking for an affordable way into modular medium format. On the secondary market, bodies typically sell for $200 - $400 in working condition. Prices climb significantly with original lenses, film backs, or rare accessories like the Polaroid back or data imprinting unit. Fully functional kits with a prism, waist-level finder and multiple backs can command $600 - $900.

When buying an ETRSi, check the shutter at all speeds, the light seals, and the condition of the mirror and focusing screen. Common problems are degraded foam light traps (replace them to prevent light leaks), sticky shutters from dried lubricants, and battery compartment corrosion (it uses a single 6V 4SR44 or PX28 battery). The electronics are generally reliable, but can fail after exposure to moisture or long-term storage without power. As with all vintage electronics, a professional CLA (Clean, Lubricate, Adjust) is recommended for cameras that have been dormant.

Similar Cameras

Mamiya 645 Super – Comparable 6×4.5cm modular SLR with interchangeable film backs and TTL metering; known for durability and wide lens selection.
Pentax 6×7 – Larger format SLR with exceptional optics; less compact but favored for portrait work.
Hasselblad 203FE – 6×6cm modular system with built-in meter and later TTL flash; significantly more expensive but industry standard.
Bronica SQ-Ai – Bronica’s 6×6cm counterpart with similar electronics and modularity.
Konica Hexar RF – Not a direct competitor, but a high-end medium format alternative with fixed lens and rangefinder design.

Repair & Maintenance

The ETRSi runs on a single 6V 4SR44 or equivalent PX28 battery, which powers the shutter speed control, metering circuit and TTL flash logic. These batteries are still available but can be costly. Some users substitute modern 4LR44 alkaline packs, though voltage regulation may affect meter accuracy. The electronics sit on a replaceable circuit board, which simplifies repairs when faults occur.

Common maintenance issues include shutter blade lubrication degradation, which may cause inconsistent speeds or complete failure at slower settings. The mirror mechanism is generally sturdy but can develop play over time. The film transport system relies on a mechanical linkage that should be inspected for wear, especially in high-use examples. Because the camera is modular, film backs, winders and body all have to be compatible. Older ETR backs are compatible, but proper electrical contact alignment is critical for frame counting and metering. Professional servicing is recommended for shutter calibration and electronic diagnostics, since specialized tools and knowledge are required.