Thread: How small can a camera be?

Is it possible to create a bug or camera or video camera which is invisible to the naked eye and which records in good quality. A camera/video camera which is microscopic just like bacteria?

In good quality?
Probably not.

Scientists have built a digital camera inspired by the compound eyes of insects like bees and flies. The camera’s hemispherical array of 180 microlenses gives it a 160 degree field of view and the ability to focus simultaneously on objects at different depths.

Human eyes, and virtually all cameras, use a single lens to focus light onto a light-sensitive tissue or material. That arrangement can produce high-resolution images, but compound eyes offer different advantages. They can provide a more panoramic view, for example, and remarkable depth perception.

The new artificial version, created by by John Rogers and colleagues at the University of Illinois at Urbana-Champaign and described today in Nature, could potentially be developed for use in security cameras or surgical endoscopes.

“The resolution is roughly equivalent to that of a fire ant or a bark beetle,” Rogers wrote in an email to Wired. “With manufacturing systems more like those in industry, and less like the academic, research setups that we are currently using, we feel that it is possible to get to the level of a dragonfly or beyond.”




https://www.google.com/url?sa=i&rct=...09155556077247

LED lights at airports can record video, alert staff to long lines and track behavior deemed suspicious



and this ...


Creating a nano-sized light source by electrostatic trapping of nanoparticles in a nanogap

K Hoshino, K Yamada, K Matsumoto and I Shimoyama
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K Hoshino et al 2006 J. Micromech. Microeng. 16 1285. doi:10.1088/0960-1317/16/7/023
Received 8 December 2005, in final form 13 April 2006. Published 17 May 2006.
2006 IOP Publishing Ltd
Abstract

A MEMS-compatible, simple fabrication technique for a nano-sized light source was developed, and its characteristics were investigated. This technique is a combination of top-down electrode fabrication and bottom-up nanoparticle trapping. As regards this technique, nanoparticles (CdSe/ZnS core-shell nanoparticles) in a solvent were electrostatically trapped in a nanometer-sized gap between two electrodes formed on a p-type silicon on an insulator (SOI) wafer. The width of the nanogap, which was created by electron-beam lithography, was 200 nm. The trapped nanoparticles maintained a bridged form between the electrodes even after the solvent evaporated. Electroluminescence from the nanoparticles in the gap was observed when a voltage was applied to the electrodes. We measured an optical spectrum of the emission to find a peak which corresponds to the bandgap of the nanoparticles. A micro-photoluminescence measurement using a 405 nm laser suggested that the rest of the electrically induced emission was the black body emission of the locally heated nanoparticles. SEM observation showed that the emission area was small, i.e., 60 000 nm2. The nano light source fabricated by our new method is useful for integration with other devices owing to the simplicity of the fabrication method.
http://iopscience.iop.org/0960-1317/...7_16_7_023.pdf


and this...
nanoLight Technologies
The nanoCam™ concept sidesteps the old external lens, allowing the camera to overcome physical-optical limitations to become truly nanosized. This revolutionary technology allows a high definition mega-pixel camera to be flattened to about the width of a human hair.
Introducing The NanoCam™
NanoCam? - An Ultra-Miniature Multi Lens Array 3D Camera

I think that when the size of the optical components become small enough to be comparable to the wavelength of light, then diffraction effects will severely impact on the quality of the image.

Originally Posted by KJW

I think that when the size of the optical components become small enough to be comparable to the wavelength of light, then diffraction effects will severely impact on the quality of the image.

Yes, and I must learn to quit being too brief in my answers.
Airy disk - Wikipedia, the free encyclopedia

There is also a question about how many pixels you can crowd into a small space, however I agree the major problem would be the difraction limiting effect of a micro-sized aperture. It does not matter how dense the pixels are if you are unable to cleanly focus the image.

Even my Zeiss microscopes run into this problem (even with monochromatic light sources) and the apertures are not "invisible to the naked eye" size either.