Silicon ChipDigital Cameras Come of Age - March 2014 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: Cruise ships are technical marvels
  4. Feature: Digital Cameras Come of Age by Barrie Smith
  5. Feature: Retro Round-Up: Nostalgic Radio Is Back! by Kevin Poulter
  6. Subscriptions
  7. Project: Arduino-Based GSM Remote Monitoring Station by Nicholas Vinen
  8. Project: Precision 10V DC Reference For Checking DMMs by Jim Rowe
  9. Review: Cadex C7400ER-C Battery Analyser by Nicholas Vinen
  10. Project: Burp Charger For NiMH & Nicad Batteries by John Clarke
  11. Product Showcase
  12. Project: 230V/10A Speed Controller For Universal Motors, Pt.2 by John Clarke
  13. Book Store
  14. Feature: A Look Back At Ferrite Core Memory: Bits You Can See by Brian Armstrong
  15. Vintage Radio: The 1956 Sony Gendis TR-72 transistor radio by Dr Hugo Holden
  16. Order Form
  17. Notes & Errata
  18. Market Centre
  19. Advertising Index
  20. Outer Back Cover

This is only a preview of the March 2014 issue of Silicon Chip.

You can view 46 of the 112 pages in the full issue, including the advertisments.

For full access, purchase the issue for $10.00 or subscribe for access to the latest issues.

Items relevant to "Arduino-Based GSM Remote Monitoring Station":
  • Arduino software for the GPRS Remote Monitoring Station (Free)
  • Arduino GPRS Remote Monitoring panel artwork (PDF download) (Free)
Items relevant to "Precision 10V DC Reference For Checking DMMs":
  • Precision 10V DC Reference Mk2 PCB [04104141] (AUD $5.00)
  • Precision 10V DC Reference Mk2 PCB pattern (PDF download) [04104141] (Free)
  • Precision 10V DC Reference Mk2 panel artwork (PDF download) (Free)
Items relevant to "Burp Charger For NiMH & Nicad Batteries":
  • NiMH/Nicad Burp Charger PCB [14103141] (AUD $15.00)
  • PIC16F88-I/P programmed for the NiMH/Nicad Burp Charger [1410314A.HEX] (Programmed Microcontroller, AUD $15.00)
  • Complementary pair of logic-level Mosfets (CSD18534KCS/SPP15P10PL-H) (Component, AUD $7.50)
  • Firmware (ASM and HEX) files for the NiMH/Nicad Burp Charger [1410314A.HEX] (Software, Free)
  • NiMH/Nicad Burp Charger PCB pattern (PDF download) [14103141] (Free)
  • NiMH/Nicad Burp Charger panel artwork (PDF download) (Free)
Items relevant to "230V/10A Speed Controller For Universal Motors, Pt.2":
  • 230V/10A Universal Motor Speed Controller PCB [10102141] (AUD $10.00)
  • 230V/10A Universal Motor Speed Controller prototype PCB [10102141] (AUD $2.50)
  • PIC16F88-I/P programmed for the 230V/10A Universal Motor Speed Controller [1010214A.HEX] (Programmed Microcontroller, AUD $15.00)
  • Parts for the 10A 230VAC Universal Motor Speed Controller (Component, AUD $45.00)
  • Firmware (ASM and HEX) files for the 230V/10A Universal Motor Speed Controller [1010214A.HEX] (Software, Free)
  • 10A/230VAC Universal Motor Speed Controller PCB pattern (PDF download) [10102141] (Free)
  • 10A/230VAC Universal Motor Speed Controller panel artwork (PDF download) (Free)
Articles in this series:
  • 230V/10A Speed Controller For Universal Motors, Pt.1 (February 2014)
  • 230V/10A Speed Controller For Universal Motors, Pt.1 (February 2014)
  • 230V/10A Speed Controller For Universal Motors, Pt.2 (March 2014)
  • 230V/10A Speed Controller For Universal Motors, Pt.2 (March 2014)

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Digital Cameras Come of Age For many people, especially those under 20 years of age, a digital camera has been the only way to take a photo. Compared with the 188-year history of photography, the rapid progress of digital cameras has been truly been remarkable and one can only wonder, now, how we put up with the hassles and horrors of silver halide photography. by Barrie Smith The first digital camera, developed by Steven Sasson (pictured) and Gareth Lloyd of Kodak was used to take a B&W image of Kodak lab technician Joy Marshall in December 1975. It weighed 4kg, took a 100 x 100 pixel image and took 23 seconds to write the image to cassette (top right) – and the same time to read it back! 12  Silicon Chip siliconchip.com.au I ’d been writing about cameras of the film variety for years, then began to delve into digital cameras specifically about 20 years ago. So the original title of this story was 20 Years of Digital Photography. Oops! In scraping only the top few layers of dust off my files I began to realise my early involvement with pixel pictures went back a good deal further than 20 years. But then I woke up to the fact that digital photography far preceded my own involvement and level of curiosity. The Dycam was the first totally integrated computer-oriented point and shoot digital camera to arrive in Australia. Where did it start? According to Wikipedia, the first digital image was produced in 1920 by the “Bartlane” cable picture transmission system, a method developed by British inventors, Harry G. Bartholomew and Maynard D. McFarlane. The process consisted of ‘a series of negatives on zinc places that were exposed for varying lengths of time, thus producing varying densities.’ The Bartlane cable picture transmission system generated at both its transmitter and its receiver end a punched data card or tape that was recreated as an image. 1951 saw the first video images recorded to magnetic tape, as analog signals. By 1956 Ampex had launched the revolutionary video tape recorder (VTR) and the American public saw the first TV program rebroadcast from tape on November 30, 1956. The first flyby spacecraft image of Mars was taken from Mariner 4 on July 15, 1965 with a camera system that used a video camera tube whose images were processed by a digitiser, rather than a mosaic of solid-state sensor elements. We cannot strictly call it a digital camera but it did produce a digital image that was stored on tape, for later slow transmission back to earth. NASA also used computers to enhance these images. Texas Instruments patented a film-less electronic camera in 1972 — a first. However it was the invention of the charge-coupled device, or CCD, in 1969 that really propelled the digital capture and storage of photographic images. In 1973 Fairchild Instruments delivered the first commercial capture opportunity with a 100 x 100 pixel CCD earlier developed by Bell Labs. This was taken up by Steven Sasson, an electrical engineer at Kodak who, with associate Gareth A Lloyd, produced the first working digital camera in 1975. The device used an analog-to-digital converter ‘stolen from a digital voltmeter application’ plus a Kodak Super-8 movie camera lens. The digital data was recorded onto a portable digital cassette instrumentation recorder. Taking its first picture (in B&W) December 1975, Sasson’s camera weighed nearly four kilograms and carried only 0.01 million pixels of memory leading to a 100 x 100 pixel image. This image took 23 seconds to record onto the cassette and another 23 seconds to read off a playback unit onto a TV. At the time Sasson predicted that digital cameras would be viable in 15-20 years. Good guess: Kodak launched its first commercially available camera in 1994 — 19 years after Steve’s invention. A video interview with Steven Sasson is well worth watching. Go to www.youtube.com/watch?v=wfnpVRiiwnM In 1981 Sony released the Sony Mavica electronic still camera — the first commercial electronic camera. Images were recorded onto a mini disc and then placed in a video reader connected to a TV monitor or colour printer. Even though it started the digital camera revolution, this early Mavica is not a true digital camera. It was a video camera that took video 570x490 pixel freeze-frames. By 1986 Kodak scientists had invented the world’s first sensor capable of recording 1.4 million pixels. It could produce a 12.5x17.5cm digital photo-quality print. In 1987, Kodak released seven products for recording, storing, manipulating, transmitting and printing electronic still video images. 1991 saw Kodak release the first professional digital camera system – the DCS100, built from a basic Nikon F3 SLR camera body and a 1.3MP Kodak CCD camera back. Dycam The 1981 Sony Mavica, the first commercially available electronic still camera – actually a video camera that took 570 x 490 pixel freezeframes. siliconchip.com.au In early 1992, I had a close look at the unusual Dycam (aka Logitech Fotoman), which I described as the ‘first totally integrated (hardware and software) computer oriented “point and shoot” digital camera to arrive in Australia.’ Neither still, nor video camera, hand-shaped and a using a hybrid of both technologies, it looked like neither. It took 320 x 240 pixel B&W images (PICT or TIFF), 32 of which would fill the camera’s 7.5MB of DRAM. The 8mm lens was fixed focus, imaging to a 1/3rd inch CCD packed with 90,240 pixels. March 2014  13 The first Apple QuickTake 100 camera was fitted with an f/2.8, 8mm lens and could take eight 640x480 images. The 32 images would remain in memory, without a battery recharge, for about one day! One oddity: because the CCD captured the images with off-square pixels it was necessary to rescale the pictures by increasing the vertical proportion by 18%. Price: $1705. QuickTake The arrival of Apple’s binocular-shaped QuickTake 100 camera (built by Kodak) in May 1994, was a landmark. At the time of my review I described it as having ‘some pluses and some minuses: no film to load, no wait for processing and — if your images are to end up inside a computer — no scanning. On the minus side, the camera had a maximum capacity of eight shots (at top resolution), no focus or exposure controls and possesses the most rudimentary flash system. But it did have an internal flash! If you’re curious, the manual can still be downloaded from http://manuals.info.apple.com/MANUALS/0/MA690/ en_US/0306161AQT100UG.pdf The first QuickTake, model 100, was fitted with an f2.8/8mm lens, equivalent to 50mm in 35mm SLR-speak. It could take eight 640x480 images, written to one megabyte of EPROM flash memory in the camera’s QuickTake format, then externally converted to PICT or TIFF format. No space saving format such as JPEG in those days! Cost: A$995. The Casio QV-10, released in 1995, was the first digital camera with a built in LCD monitor, and is credited with at least kick-starting the whole digital camera revolution. My comment on the picture quality of this camera was: ‘Colour quality … surprisingly good, well saturated and, provided your exposure was within the ball park, a little judicial fiddling with Photoshop … could reward you with excellent results.’ This was followed a few months later by the Kodak DC40 in 1995, the Casio QV-10 (first with an LCD screen), and Sony’s first Cyber-Shot camera in 1996. Retail stationery company Kinkos and Microsoft both collaborated with Kodak to create digital image-making software workstations and kiosks which allowed customers to produce CDs and prints. Hewlett-Packard was the first company to make colour inkjet printers that handled the output of digital images. While Kinkos has gone the way of the dodo, surprisingly these retail printing outlets are still extremely popular at outlets such as Officeworks and Big W as mums and dads sit at the easy to use workstations and pump out 10x15cm prints at 9 and 15 cents respectively. Perhaps this popularity is not so surprising when you compare the alternative to printing your 10x15cm snaps as printer manufacturers such as HP, Canon and Epson continue with their rapacious pricing policies of ink cartridges, let alone the cost of self- Above: Kodak’s DC40, released in 1995, while at right is a more recent Kodak camera from 2003, the EasyShare DX6490, with the (then) enormous zoom range of 10x. 14  Silicon Chip siliconchip.com.au purchased printing paper. Progress At this point digital cameras were still relatively primitive. What was needed for the technology to really take off was an increase in resolution, a rise in image quality, smarter and faster internal processing, more sophisticated storage methods, better lenses with a longer zoom range. All of this happened over the next decade and we’re still progressing. From this distance it is truly amazing that the early digicams, such as the first QuickTake and the Dycam 1 caused so much excitement, especially if you consider their image resolution as measured in pixels. The usual rule-of-thumb to determine final print dimensions is to divide an image’s resolution by 300 (inches) or 118 (cms). So, the QuickTake’s 640x480 pixel images could produce a print 2.13 x 1.6 inches or 5.42 x 4.1cm in size. In recent years, with a ‘decent’ quality digital image, the 300/118 factor has been found to be ‘stretchable’ to 200/79 (inches/cms) My first printer capable of working with digital images was a C Itoh ImageWriter dot matrix model, marketed by Apple. It weighed a ton, cost a motza and produced atrocious prints. This printer was better suited to text output and even then its quality compared badly to today’s inkjet models, which appeared in the 1980s and made by such companies as Canon, Epson, HP and Lexmark. Today, the quality of 21st century prints made by photo quality printers — both inkjet and dye sublimation methods as well as some colour laser printers — is truly remarkable and easily rivals the best made by traditional photographic methods. In camera sensors, today’s digital cameras use a CCD or (increasingly) a CMOS image sensor. CCD and CMOS sensors convert light into electrons. While there are numerous differences between the two sensors, they both read the value of each cell, or pixel, in the image. The more pixels in the sensor, the more detail it can capture and deliver larger output in the way of an acceptable print. Or so you would think: in recent years consumers have been persuaded to assess comparable digicams by comparing the Canon’s PowerShot SX50 HS has an exceptional wide/ telephoto zoom, as seen below. megapixel count of each. But those clever camera makers have shrunk the size of each pixel, so now a $200 camera can have a sensor with the same pixel count as a $2000 digital SLR (DSLR) … but the latter’s sensor will be larger, so the pixels are larger and less likely to produce artefacts such as noise. Another difference between sensors is dynamic range with (naturally) less expensive cameras usually delivering lower range. Early cameras relied on limited internal memory but, as demand for increased resolution rose, so did the need for a better method of storage. Enter the flash memory card To my mind this is an incredibly clever device which first saw application in digital photography in the form of the CompactFlash card, quickly followed by SmartMedia (both of which are now largely superseded), Sony’s Memory Stick (in all its variations) and most recently the MultiMedia Card and SD card (and variations). In most cases, the MMC Canon’s recent PowerShot SX50 HS with a 50x zoom has a 35 SLR equivalent of 24mm to 1200mm in range. These views of Narrabeen Lagoon demonstrate its capabilities – the telephoto shot on the right is of the area marked by the red rectangle on the wide-angle shot at left. Can’t see it? Look closer! You needed to bear in mind that, as the manual states, ‘using the tele end of the zoom will see you face off atmospheric haze.’ siliconchip.com.au March 2014  15 This to scale (but not to size) image shows the evolution of flash cards over the years. The CompactFlash and SmartMedia cards (at left) have been largely superseded; even the still very popular SD (and MMC) cards have given way to very much smaller SD variants, driven by their popularity in mobile phones and tablets. The tall blue card is the original Sony MemoryStick; it too has been largely replaced by Sony’s Memory Stick PRO Duo and M2. At right is Fuji’s proprietary XD card which proved quite unpopular as (like the Sony) it fitted little else and most computers didn’t sport XD card readers. and SD cards are interchangeable if they are of the same physical format. Incidentally, some incantations of SD cards especially have different names, dependent on the manufacturer – for example SD and T cards. Aside from Sony with its proprietary Memory Stick cards, two companies (Fujifilm and Olympus), saw a market opportunity and launched the xD-Picture Card, usable by only these company’s cameras. By 2010 the card was obsolete due to its inability to match the write/read speed of CompactFlash and SD cards as well as the enormous takeup of the latter (especially the miniature versions) by mobile phones. The market battle at the consumer level today is between cameras offering not only high ‘pixel populations’ but also extensive zoom specifications. I well remember an early Kodak camera, the EasyShare DX6490, which had (to me) the enormous zoom range of 10x and sold for $1099. Called ‘maxi zooms’, these digicams with enormous zooms had enormous appeal and the category was topped by Canon’s PowerShot SX50 HS that boasted a 50x zoom that ran from a 35 SLR equivalent of 24mm to 1200mm in range. I say ‘was’ because news has just come through that Panasonic now have a Lumix DMC-FZ70 with 60x zoom and a 16 megapixel sensor! But all is not rosy in maxi zooms of this range: move from the maximum wide angle to the tele end and the maximum aperture of f2.8 quickly shrinks to f6.3! That’s fine for brightly-lit (ie, sunny!) scenes but not good indoors or at night. Top level DSLRs like Canon’s EOS Mark 5 III, Sony NEX-7 and Nikon’s D4 model are used in TV drama and feature film production to capture the action that ends up on the giant movie screen. 16  Silicon Chip My review of the Canon camera at the time pointed out that, while the image quality was ‘above average’, you needed to bear in mind that, ‘using the tele end of the zoom will see you face off atmospheric haze. The shot of the bridge shot at full tele and shown here was 1.8km away. To use it: ‘hard to deal with, you need some patience, a decent tripod and suitable subject matter to use it satisfactorily … if you plan to do any amount of long lens shooting, go get yourself a decent tripod; try out the camera in the store before you buy and avoid wobbly legs!’ My full review is at: http://digital-photography-school. com/canon-powershot-sx50-hs-review Today most cameras will capture and write image files in JPG (usually referred to as JPEG) or RAW formats. With JPEG it’s a balancing act between compression, processing speeds, memory capacity… and of course, image size: at the highest compression level the image size in bytes can often be reduced dramatically. A compression factor of 10:1 can often have little effect on the picture quality. An image of minimal detail will compress to a smaller file in bytes than an identically sized image of maximum detail. For example, images with large areas of sky will suffer less and compress to a smaller size in megabytes. A crowd of faces will tolerate less compression and lead to a larger file size. JPEG is also unsuited to multiple edits and saves – some image quality will usually be lost each time a picture is decompressed and recompressed. A rule-of-thumb is 5-10% each time. The ideal approach is to save the ‘master’ JPEG immediately after it is downloaded from the camera and Facing off the DSLRs in movie work are the more traditional, purpose-designed video camera/recorders such as the Arri Alexa. siliconchip.com.au Need to get rid of halogen ceiling lamps?? FORGET HALOGEN GLOBE REPLACEMENTS THIS IS THE BETTER WAY! 4" & 6" Down Lights Sony’s NEX-3NL “prosumer” 16MP camera – as small and light as a point-n-shoot but with interchangeable lenses – said to have the best image quality of any compact camera. work with copies for subsequent image processing. The RAW format is increasingly seen on even mid-range fixed lens digicams and is regarded by many experts as the ideal way to deal with digital camera images, as a RAW image is written to memory from minimally processed data transferred from the image sensor. However, unprocessed these files are not printable nor editable with most software. RAW images need to be converted to other formats (TIFF, JPEG etc) to undergo subsequent transformation or output. Some cameras, such as those made by Nikon, Sony and others use a proprietary format and may require translation to a Photoshop-readable RAW format. JPEG/RAW Pros and Cons JPEG files are smaller (often significantly so); they usually have sufficient quality for most purposes; they’re quicker to shoot (camera processing is quicker). A JPEG image is 8-bit (256 brightness levels). RAW files holds the maximum amount of data about the image, later retrievable; white balance has not been set and can be determined later; most RAW files are captured with 16-bit information (65,536 brightness levels). DSLR vs Compact Another question that faces the amateur with ambitions to make an impression on the photographic world: is the DSLR the better way to go? I frequently like to quote my maxim: it’s the driver, not the car! An extreme comparison is to see fabulous images captured by a top pro with a consumer level, fixed lens camera, while over on the other side of the picture you will see, very frequently, really poor images taken by a raw amateur, using a DSLR and top quality lens package whose total purchase price could easily have bought a small Asian sedan! These days, “consumer level” cameras are impressive and some models have impressive specs – far more than the average user will need in most circumstances. But if you’re really serious about digital photography (and you know your stuff!) nothing beats a professional model. And don’t forget, between the two extremes there really are some outstanding buys around – quite high spec models at prices we could only dream about just a few years ago. Why pay SC more than you need to? siliconchip.com.au As reviewed SILICON CH IP Feb 2013 $AVE $$$$ IN POWER BILLS! LED HIGHBAYS To replace those power-hungry mercury high-bays in factories, warehouses, As reviewed etc. SILICON CH IP Feb 2014 Powered by CREE LEDs LED FLOOD LIGHTS For external/internal use replacing hot & inefficient QI and mercury floodlighting. Very bright, cover a very wide area! March 2014  17