When purchasing a 120, 220, or 135 Film Back for the Bronica ETR System, it is important to be able to determine which generation of component you are being offered. This knowledge will allow you to select a newer component, with less chance of failure, and greater ease of use.
Before continuing, please make sure you are familiar with the various components of Bronica ETR System film backs.
The following features can be used to distinguish between different generations of film backs, and their various sub-components.
Opening Mechanism (frame)
The opening mechanism is located at the top front of the film back, and is used to open the film back frame, providing access to the insert for loading film.
| Generation | Description |
|---|---|
| ETR | Single release button, arrow shaped with 6-sides. Push button towards center of back to open. |
| ETRS | Single release button, rectangular shaped, with safety lock under the release button. These backs can be fiddly to operate – push the safety lock towards the camera body, then push the release button towards the center of the film back. |
| ETRS Mk-II | Dual release buttons, with long arrow icon. Squeeze both buttons towards center of back at same time to open. |
| ETRSi | Dual release buttons, with encircled arrow icon. Squeeze both buttons towards center of back at same time to open. |
Film Winder (insert)
Located on the lower right side of 120 and 220 film backs, the winding handle is used to advance the film during loading. Note that the 135 film backs also have a winding handle in this location, however the design of this handle did not change across the various generations.
| Generation | Description |
|---|---|
| ETR, ETRS | Half-moon shaped winding handle (prone to breaking if not properly closed). |
| ETRS Mk-II | Thumbwheel winding crank. |
| ETRSi | Folding crank handle. |
Dark Slide
The dark slide is used to protect the film from light when the back is not attached to the camera body.
| Generation | Description |
|---|---|
| ETR, ETRS, ETRS Mk-II | Black colored handle, no locking mechanism (slide can be removed when the film back is not attached to the body). |
| ETRSi | Grey colored handle, with locking mechanism preventing the dark slide from being removed when the back is not attached to the camera. |
Serial Number (frame)
The serial number is shown on the top side of the back, between the opening tabs (or to the right of the single opening tab on ETR and ETRS generation backs).
| Generation | Description |
|---|---|
| ETR | “M52” followed by 4 digits. |
| ETRS | 120 backs: “M52” followed by 5 digits. 220 backs: “M53” followed by 5 digits. 135 backs: “M52” followed by 6 digits. |
| ETRS Mk-II | “81” followed by 5 digits. |
| ETRSi | “83” followed by 5 digits. |