As autofocusing logic, circuitry and mechanisms became better and cheaper, autofocus models seem to have largely supplanted fixed-focus cameras. However, fixed-focus cameras survived in the marketplace for a long time, thanks in part to the improvement of emulsions for fast films and to small, built-in electronic flashguns. As an example, the Fuji Hi! Mickey Mouse camera of 1995 has such a built-in flashgun, an 33mm f/8 lens;[1] the hyperfocal distance for such a lens is about 4.6m and if this is indeed its fixed focus then at f/8 everything from 2.3m to infinity is in focus (at f/16, everything from 1.52m).[2]

OpticalFlatfilter

Fixed-focus cameras typically restrict their widest aperture to f/8 or smaller, to yield adequate depth of field. Depth of field decreases with longer lens focal length, and the focal length of a "standard" lens scales in proportion to the image-format dimensions. So a fixed-focus camera for 35mm film will give greater depth of field than one for 120 film.

Other fixed-focus cameras include those for prison mug-shots. The MPP Prison camera, for example, has a fixed-focus 135mm or 150mm lens for two exposures on 4×5 in. sheet film.[3]

Flatoptics with designer metasurfaces

For centuries, optical instruments remained bulky and expensive. They were produced by refining mechanical parts, usually in glass, that manipulate the light in order to sense, measure, make projections, ...

It’s only recently that there’s an alternative for this traditional approach: nano-optics delves into the toolbox of the semiconductor industry. The idea is to create nanostructures that fulfill optical functions. Examples of such functions are focusing and color splitting – at a wavelength scale and with visible as well as infra-red light.

The cameras built into cheaper mobile phones are fixed focus (although they may add a "macro" switch for two focusing distances rather than one).

At imec, we support the full development of flat optics components such as filters, polarizers and lenses. Based on your requests, we:

Want to integrate nanoscale optical components in your innovative products such as cameras, displays or sensor systems? Imec helps you with the full development process.

Fixed focus is generally only used on the cheapest cameras of any period. Box cameras are often fixed-focus, as are the cheapest toy cameras. The next level of control is two-zone focus, by use of a built-in auxiliary lens (e.g. to give 'portrait' range with better box cameras). Slightly better cameras have zone focusing (a full focus range, but marked only in zones, typically for a single portrait, a group, and a landscape) or scale focusing, with the actual focus distance marked.

A camera with a fixed focus (or "panfocus") lens has no focus control. The focus is preset by the designer, usually at a distance for which depth of field will reach infinity even at the greatest aperture possible with the lens. Such cameras are sometimes labeled with the euphemism "focus free," but this should not be confused with true autofocus.

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Want to dive into this toolbox? Imec is ready to help you with the development and integration of such nano-optics components in its state-of-the art cleanrooms. And we can guide you towards large-scale manufacturing.

The miniaturization of optical components enables their integration into complex systems-on-chip. This opens the door to product innovations in markets such as:

The main advantage of nano-optics? Its compactness compared to traditional macro-optics. Moreover, nano-optics (or flat optics) components are processed using well-established techniques from the microchip industry, such as lithography and thin-film deposition. The result is that manufacturing becomes cheaper and easier to upscale.