There are multiple types of multi-lens cameras, each which has a different function. The most common four are: Twin lens, stereo, action sequence, and mini-portrait cameras.

But one of the earliest multi-lens cameras (early 1900s) was a multiplying camera, the Royal Mail Photo Stamp Camera, which was a wooden box camera that took plates. There was a three lens model and a 15-lens model (below) that could take direct photos, or copy cabinet portraits.

Royal Mail Photo Stamp Camera

Royal Mail Photo Stamp Camera Advert

Multiplying tintype camera
Twin Lens- These cameras technically have two lenses, but only one “taking lens”, and one “viewing lens”. They are oriented vertically, and the top lens on a twin lens camera is what makes your image visible in the viewfinder (or on the glass in a waist level) so that you can frame and focus, while the bottom lens is the one that actually takes the picture. There are many brands that make twin lens cameras including Yashica, Mamiya, Minolta, and probably the most popular, Rollei. Twin lens cameras are typically medium format, although there is a newer model that takes 35mm film (the Blackbird, Fly Camera- a plastic/”toy” TL).

Medium format twin lens- L: Rolleoflex, R: Minolta Autocord

Shot taken through the viewfinder of a medium format twin lens camera *

35mm twin lens, the Blackbird, Fly Camera
Stereo (3D)- These cameras have been around for a long time and usually have two or three lenses on them. They are set up to take two images that are almost the same, but are slightly off from one another so that when you view the images in a stereo viewer (or sometimes stack them and wear glasses), the result is a 3-dimensional image. They are oriented horizontally, and the cameras with three lenses have two taking lenses, and one viewing/focusing lens. These are not popular cameras for actual use these days, but are great vintage cameras to collect. Stereo cameras have been made in all formats including large format, medium format, 35mm, and subminiature. A few brands that made these cameras are Kodak, Stereo Realist, Coronet, Nimslo, and View-Master. The View-Master cameras took images specifically to be cut and put into View-Master reels (see below).

Illustration of a stereoscope (stereo card viewer)

Stereo cameras- L: Kodak Stereo, R: Stereo Realist, Bottom: View-Master Color Mark II

Film shot with the View-Master Color Mk II *

A View-Master viewer with image reel
Nimslo is one of the more modern stereo camera brands (as is Nishika), which was around in the 1980s. These cameras had four lenses (and took four images), and required your film to be processed in a special way (which is no longer available). The result was a holographic-type print that didn't require a viewer or glasses to see it in 3D.
Nimslo camera

A Nimslo print

Mini Portrait- Also called “Passport Cameras”, these are Polaroid cameras (Fujifilm also made a version though) with two or four lenses that take two (or four) images simultaneously and places them next to each other on the film (often type 100 pull-apart). They were used to take images to be used on passports or other identity cards. One of the fun things about these cameras is that you can cover one lens, take a photo, and then cover the other lens and take a photo to create Polaroid diptychs.

Polaroid Mini-Portrait Camera

Shot taken with a Mini-portrait/Passport camera as it's supposed to be (same image both sides) *

Shot taken with a Mini-portrait/Passport camera, one side at a time *
Action Sequence (Lomography)- Action sequence cameras are the newest of the multi-lens cameras, and fall into the LOMO/plastic camera/toy camera category. These cameras have anywhere from four to nine lenses on them and take multiple images (on one section of 35mm film) in rapid succession. If your subject is moving at a quick enough pace, the camera will capture that movement in the series of images. If not, then you will end up with a print of X of the same images.

A selection of LOMO Action Cameras- Clockwise: SuperSampler, Actionsampler, Pop9, Oktomat