It was a picture of his wife, Margaret Tompsett. The Cromemco Cyclops, a digital camera developed as a commercial product and interfaced to a microcomputer, was featured in the February 1975 issue of Popular Electronics magazine. It used MOS technology for its image sensor. An important development in digital image compression technology was the discrete cosine transform (DCT), a lossy compression technique first proposed by Nasir Ahmed while he was working at the Kansas State University in 1972. DCT compression is used in the JPEG image standard, which was introduced by the Joint Photographic Experts Group in 1992. JPEG compresses images down to much smaller file sizes, and has become the most widely used image file format. The JPEG standard was largely responsible for popularizing digital photography. The first self-contained (portable) digital camera was created in 1975 by Steven Sasson of Eastman Kodak. Sasson's camera used CCD image sensor chips developed by Fairchild Semiconductor in 1973. The camera weighed 8 pounds (3.6 kg), recorded black-and-white images to a cassette tape, had a resolution of 0.01 megapixels (10,000 pixels), and took 23 seconds to capture its first image in December 1975. The prototype camera was a technical exercise, not intended for production. While it was not until 1981 that the first consumer camera was produced by Sony, the groundwork for digital imaging and photography had been laid. The first digital single-lens reflex (DSLR) camera was the Nikon SVC prototype demonstrated in 1986, followed by the commercial Nikon QV-1000C released in 1988. The first widely commercially available digital camera was the 1990 Dycam Model 1; it also sold as the Logitech Fotoman. It used a CCD image sensor, stored pictures digitally, and connected directly to a computer for downloading images. Originally offered to professional photographers for a hefty price, by the mid-to-late 1990s, due to technology advancements, digital cameras were commonly available to the general public. The advent of digital photography also gave way to cultural changes in the field of photography. Unlike film photography, dark rooms and hazardous chemicals were no longer required for the post-production of an image – images could now be processed and enhanced from a personal computer. This allowed photographers to be more creative with their processing and editing techniques. As the field became more popular, digital photography and photographers diversified. Digital photography expanded the field of photography from a small, somewhat elite circle to one that