Similar lens-free "computational photography" techniques have been described for super-resolution microscopy (see below). In conventional imaging, lenses resol

Similar lens-free "computational photography" techniques have been described for super-resolution microscopy (see below). In conventional imaging, lenses resolve a sharp image of the target onto the sensor by focusing just the light emitted by the target within the lens' "focal plane" (a volume in front of the lens determined by the width of its aperture and the wavelength of the light passing through it) while blurring light from everywhere else into background noise. One can think of this system as amplifying certain information (the light from the focal plane) while filtering out other information (the light from everywhere else) from the total input light. In other words, the images formed by lenses are lossy by design. This isn't practically a problem at macroscales, but at microscales the focal plane becomes extremely thin (micron-scale), oftentimes 1/100th as thick as the sample being imaged. To image large cells, for instance, a microscopist might be forced to capture tens or hundreds of images of the sample from different focal lengths (a "z-stack"), then deconvolve them to generate an image in which most/all of the sample is in focus. Anyway, I think these new techniques are interesting because they fundamentally attempt to capture more of the "information" present in the incident light. The lens does not capture an "image" that can be directly visualized, but rather a more full representation of the wave-field of all the incident light. Generating a conventional image from the raw data requires sophisticated additional processing. The Ozcan lab has published some really neat (and eminently DIYable) work in this area: "Lensfree On-chip Tomographic Microscopy Employing Multi-angle Illumination and Pixel Super-resolution", Serhan O. Isikman, Waheb Bishara, and Aydogan Ozcan. J Vis Exp. 2012; (66): 4161. doi: 10.3791/4161. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3487288/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3487288/ "Existing 3D optical imagers generally have relatively bulky and complex architectures, limiting the availability of these equipments to advanced laboratories, and impeding their integration with lab-on-a-chip platforms and microfluidic chips. To provide an alternative tomographic microscope, we recently developed lensfree optical tomography (LOT) as a high-throughput, compact and cost-effective optical tomography modality. 7 LOT discards the use of lenses and bulky optical components, and instead relies on multi-angle illumination and digital computation to achieve depth-resolved imaging of micro-objects over a large imaging volume. LOT can image biological specimen at a spatial resolution of <1 μm x <1 μm x <3 μm in the x, y and z dimensions, respectively, over a large imaging volume of 15-100 mm3, and can be particularly useful for lab-on-a-chip platforms." Also see http://spie.org/newsroom/technical-articles-archive/3979-multi-angle-illumination-with-pixel-super-resolution-enables-lensfree-on-chip-tomography?ArticleID=x84293 http://spie.org/newsroom/technical-articles-archive/3979-mul...