The Seagull 4B is a two-lens reflex camera. The medium format camera was built by Shanghai Camera Factory. It is the successor of the Seagull 4A. There are some submodels of the 4B with slightly different features.
The lens of the Seagull 4B cannot be changed. The lens has a maximum aperture of f3.5 and the focal length is 75 mm. It therefore bears the designation “HAIOU SA-85”. The lens is focused manually with a wheel on the side and with through the shaft finder. The Seagull 4B does not have an autofocus. The closest focusing distance is 1 meter for this lens.
Exposure is not metered by the camera. Exposure time and aperture can be selected manually. The medium format camera has a Bulb mode. In Bulb setting, the remains open as long as the photographer keeps the shutter button pressed. The use of a flash is possible via the PC flash socket.
Films for the Seagull 4B
What kind of films does the Seagull 4B need? It needs medium format films. These are still easy to get today and are still being developed.
Possible films for the Seagull 4B are the Kodak Portra 160* for color photos and the Ilford HP5* for B&W images. The development of the color film is the C-41 process. The C-41 process is performed by almost all photo labs.
The medium format camera exposes a format of 6 x 6. With an insert find also shots in the format 6 x 4.5 format possible. The film is rewound in the camera manually with a wheel and with the help of the numbers, which can be seen through a red window on the back.
The medium format camera has a built-in self-timer. In addition, there is a connection for a cable release and a thread for a tripod. The medium format camera is mechanical and can take photos without batteries.
You can still buy the Seagull 4B in used condition. Depending on the state of preservation, the cost of the medium format camera varies.
Technical datasheet
| Attribute | Specification |
|---|---|
| Type of Camera | Twin-lens reflex camera |
| Film format | 120 |
| Film transport | Manual |
| Picture format | 60 mm x 60 mm, 60 mm x 45 mm |
| Focal length | 75 mm |
| Widest aperture | f/3.5 |
| Minimum focus distance | 100 cm / 3.28 ft |
| Focus | Manual |
| Viewfinder | Waist-level finder |
| Exposure times | 1/300 second to 1 second, Bulb |
| Bulb mode | Yes |
| Date imprinting | No |
| Built-in flash | No |
| Tripod mount | Yes |
| Cable release thread | Yes |
| Self-timer | Yes |
| Power supply | Not necessary |
| Company name of the brand | Shanghai Camera Factory |
| Country of production | China |
| Estimated value / Used price | 108,43 Euro Estimate based on used prices of 17 offers (possibly with different scope of delivery and/or condition). As of June 15, 2026 |
| Average used price in the year 2023 | 172,17 Euro (186.17 US-Dollar) |
| Average used price in the year 2024 | 139,73 Euro (150.45 US-Dollar) |
| Average used price in the year 2025 | 121,86 Euro (130.97 US-Dollar) |
FAQ about the Seagull 4B
Is the Seagull 4B a digital or film camera?
The Seagull 4B is a film camera. It uses 120 roll film, a type of medium format film, to capture images. This means you'll need to have your film developed after shooting.
How do I focus the lens on this twin-lens reflex camera?
The Seagull 4B's lens focuses manually. You adjust the focus using a ring on the side of the lens, while viewing the image through the viewfinder. It doesn't have autofocus.
Does the camera measure the exposure automatically?
No, the Seagull 4B doesn't have a built-in light meter. You need to set the aperture and shutter speed manually based on your lighting conditions.
What kind of film does this medium format camera use?
The Seagull 4B uses 120 roll film, which is a medium format film. Both color and black and white films are available, making it fairly easy to find film.
Can I use a flash with the camera?
Yes, the Seagull 4B has a PC flash sync terminal, allowing you to connect and use an external flash. This allows for flash photography.