The lens used for the sensor sensitivity tests was a Nikon Rayfact 105 mm f4.5 UV macro lens with appropriate lens mount adapter (the lens adapter did not contain any additional optics). The multispectral and monochrome conversions were carried out by Llewellyn Data Processing LLC, Carlstadt, NJ, USA. The relative contributions of the CFA and microlenses to the observed sensitivity are also discussed.Ĭanon EOS 5DS R UV–Vis–IR monochrome conversion with the CFA/microlenses and internal IR filter stack removed, and sensor cover glass replaced with a Schott WG280 window. Images in the UV and IR are also included here to demonstrate the observed sensitivity results. Enhanced UV sensitivity for the monochrome converted cameras was quantified by using a newly defined method, using narrow band-pass optical filters. Sensitivity was assessed between 300 and 800 nm for a variety of test cameras with traditional sensor designs and backside illuminated (BSI) sensors. This article describes how the sensitivity of a range of monochrome converted digital cameras compares to both standard and multispectral converted (UV–Visible–IR) cameras. These extra steps can be especially important factors if the photographer is interested in imaging in the regions beyond visible light, such as the ultraviolet (UV) and infrared (IR), and for multispectral imaging using band-pass optical filters or tightly defined light sources. If a monochrome image is the desired end result, the processing first to create a color image, and then to remove all that color information again, would seem to be overly complex, and could impact the quality of the final image. However, it should be remembered that the sensors themselves are originally monochrome, and the processes applied to them during manufacturing enable color images to be generated, typically through the use of a Bayer or color filter array (CFA) or by relying on the depth of penetration of different wavelengths of light within the sensor. Most consumer cameras use color sensors and include a way of creating monochrome images within the camera software, or the users can convert their color images to monochrome later, using a wide range of software packages. However as digital-camera manufacturers have continued to push the boundaries with sensor design, and increasing pixel count and dynamic range, outside of the machine vision and scientific camera areas, relatively few have created cameras with dedicated monochrome sensors. In the early 1990s, with the first consumer-orientated digital camera, the Kodak DCS 100, a monochrome camera option appeared alongside a color version. The first photographs were, of course, monochrome, but by the beginning of the 20th century, commercial processes for creating color photographs were starting to be developed. “Do you prefer to shoot in color or monochrome?” Few questions in photography can prompt discussion the way the one of whether color or monochrome is your preferred approach to imaging does.
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