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Digital Still Cameras

Copyright Daniel Rutter 1996. All rights reserved.

 

With models available for less than $1000, people are scooping up digital cameras in droves and taking pictures of anything and everything, entranced by the fact that they can produce an instant image on their computer screen with no film, no processing and little fuss.

Web designers can get a shot of anything onto a page in a couple of minutes. Real estate agents and insurance professionals can save time and money on the plethora of pictures they go through. Professional journalists can grab shots and email them to their publication speedily, and amateur newsletter producers can capture pictures just as easily. The applications for digital still cameras are legion, and the ratio of price to performance is becoming attractive for both amateur and professional users.

In this comparison, we lined up cameras from the cheapest model available anywhere - the Kodak DC20, at less than $500 - to medium-range professional models costing $12,000. To say that there’s something for everyone is overstating the case - digital still cameras are still expensive for what they do. But between these still cameras, cheap high grade video grabbing and Photo CD, it’s hard to find an image acquisition need that isn’t met by recent digital developments.

 

Epson PhotoPC

Epson’s PhotoPC, is a rebadged Sanyo VPC-G1, aimed at the lower end of the market. It lists for $999, and will no doubt be available for less. The PhotoPC sports a conventional focus-free compact camera design, with flash, separate viewfinder almost directly above the 43mm-equivalent lens and a lens protector/cap that snaps aside when you turn the camera on. There’s a flash, which can be set permanently on, permanently off or to auto mode, and the usual ten second timer for those moments when you want a complete stranger to walk off with your unattended camera while you pose with the family.

It has a standard 37mm thread for camcorder lenses or filters, but any changes you make to the camera’s view are not reflected in the separate viewfinder. The lens will focus from 60cm to infinity. There is no macro mode for close-ups. The camera remembers the date and time when each image was taken, but there are no further in-camera labelling functions.

The PhotoPC runs on four AA batteries and comes standard with 1Mb of memory, enough for 32 of its 320 by 240 low resolution pictures or 16 640 by 480 high res shots. The camera we reviewed came with a $570 4Mb memory expansion, which extends its storage to 80 high or 160 low res pictures. A 2Mb expansion module for $340 is also available.

The pictures are squeezed into the limited RAM by means of JFIF (JPEG) compression. The compression is pretty high - 16 images per megabyte is a lot - but for many purposes image quality is more than adequate. A preset compression ratio can’t be expected to deal with all situations, and fine detail can be lost in the JPG compression squares. Viewing the images at 100% magnification, the compression is seldom very notable, but magnified images or shots of unusually "fiddly" subjects like a flowery garden bring out the compression artefacts. Higher magnification or sharpening the image also emphasise the artefacts.

The PhotoPC connects to a PC or Mac via a standard serial cable, and the software supports transfer speeds up to 57600 bits per second. At this speed, it takes under ten seconds to transfer a 640 x 480 image. Only if you own an antique computer incapable of higher serial port speeds will you have to put up with the default 9600 BpS transfer speed.

We evaluated the Windows software, which includes a standalone image transfer and remote operation package from which you can drag and drop pictures to your programs. There’s also TWAIN drivers for Windows and Macintosh, which let any TWAIN-compliant package retrieve images or remotely trigger the camera.

There’s not much to gripe about, considering the PhotoPC’s price. There’s no reason for a digital camera to be "camera shaped", since they don’t have to actually hold a roll of film, but this one is. Digital cameras based on the "Luke Skywalker’s binoculars" model are more comfortable to use than ones shaped like the traditional brick. The PhotoPC uses a green LED next to the viewfinder to tell you when it’s ready to take a picture. In daylight, this LED’s status is impossible to determine and so you have to guess when it’s finished compressing the last picture.

These problems are minor niggles, at best. For the money, the Epson PhotoPC is a good unit. The images have good tone and hue balance, and need only a mild unsharp mask operation to make them suitable for any application that can stand 640 by 480 resolution.

 

Polaroid PDC-2000

Polaroid’s PDC-2000 is a "low-midrange" digital camera. Or perhaps a "very high consumer" one. What do you call a camera with the separate viewfinder and binocularish design of the cheaper digitals and no zoom or manual focusing, but with image quality which at least approaches that of far more expensive digitals?

The PDC-2000’s focus system uses the sonar transponder system seen on Polaroid’s self-developing instant cameras. Instead of moving the lens, the camera moves the CCD to one of 60 positions according to the range to target. Polaroid say this technique improves accuracy; perhaps they’re right. You can deactivate autofocus or lock the focal distance, but there’s no manual focus adjustment.

The standard lens on the Polaroid is an f2.8 11mm, equivalent to a 38mm lens on a 35mm film camera. You can swap it for an optional 17mm lens (equivalent to a 60mm), whereupon you use a box inside the viewfinder to define your scene, instead of the whole view.

This viewfinder, by the way, is not as easy to use as those on cheaper separate-viewfinder digitals. It feels like looking through a telescope - you have to line your eye up well with the finder to see anything at all, and it’s a pain for those who wear glasses. There’s no compensation box for close-ups, so shooting nearby subjects without tethering the camera to your computer and previewing over and over is very annoying.

The PDC-2000’s flash, on the other hand, is good - it automatically selects full, fill or ambient flash mode, and it’s much brighter at full power than the tiny strobes on cheaper models.

The PDC-2000 uses a SCSI interface for image transfer, which is just as well - its 1Mb images would take two and a half minutes each to transfer via a 57,600 BpS serial link. On the down side, this means you’ll need a SCSI card in your IBM compatible (not a problem for Mac users) and plugging and unplugging the camera is awkward, because it’s permanently terminated and must be the last device on the SCSI chain. The manual contains dire warnings that everything in a five mile radius must be turned off before plugging or unplugging a SCSI device, and indeed data corruption can occur if something tries to write to a device when the SCSI chain isn’t correctly terminated, but you may get away with unplugging the camera and reterminating the last device, as long as nothing looks too hard at the SCSI configuration and gets alarmed.

One warning you should take note of, though, is the one that says not to power the PDC-2000 with anything other than nickel cadmium rechargeable cells (it uses four AA size). The camera’s current draw is too high for conventional alkaline or even lithium non-rechargeables to handle - and when plugged into its mains power supply it tries to charge its batteries, which is a very bad thing to try with ordinary cells. The camera’s standard charge rate is slow - six hours for a full charge - and investing in another couple of sets of batteries and/or a fast charger could be a good idea. The batteries are said to last at least 150 shots, but fewer than 100 seems more realistic, especially using the flash.

The CCD in the Polaroid has an unusual design - its resolution is 1600 by 600 pixels, with pixels twice as tall as they are wide. This means that the Polaroid’s maximum output resolution, 1600 by 1200, is interpolated vertically and isn’t actually built out of 1200 vertical pixels of data. The interpolation is visible in images as jaggies where none should be - however the PDC-2000 produces very good images, with great tone balance and reasonable sharpness, but it’s not as good as the resolution figures might imply. On close inspection, mild banding is visible in dark areas of the picture - but you do have to be looking closely.

The model we tested, the PDC-2000/40, has a 40 megabyte internal hard drive to store images. Two other models, the 2000/60 and the 2000/T, have a 60Mb flash RAM drive and no internal storage at all, respectively - the T model is meant for permanent connection to a computer, and the notably more expensive 60 for field work where the 40’s hard drive might not survive.

Unfortunately, Polaroid seem to have fallen between two stools with the PDC-2000. Most users will run a mile at the first mention of the price tag, and the professionals who might go for a camera at this price will be unimpressed that this is a non-standard camera that can’t take 35mm lenses or flashes and has a separate viewfinder, no zoom and no manual control of exposure, aperture or shutter speed. You can screw standard photographic filters onto it, but that ain’t much compensation. The PDC-2000 delivers unquestionably better results than all of the cheaper cameras in this comparison - but it’s priced way out of that market. At half the price, it might do better.

 

Casio QV-10

Casio’s QV-10 is a superficially desirable gadget with lots of impressive features and one serious flaw.

The most impressive thing about the Casio QV-10 is its small size. The main body of the camera’s a little longer and narrower than the palm of the average hand, and on the end is an extra swivelling section that bears the lens.

The second most impressive thing about this camera is the little 1.8 inch LCD display panel on the back, which gives you a stuttery but useable running preview of whatever the lens is pointed at. The swivel lets you point the lens at yourself and see what it’s seeing, or hold the camera over your head and still see the screen.

The third most impressive thing about the Casio is its video output - you can plug in a lead and connect it to anything that accepts composite video. This means you can record your captured images to videotape or quickly preview them on any composite-capable monitor, which includes most TVs. And the Casio stores 96 pictures in its unexpandable 2Mb of memory, which is pretty good for a $1000 unit.

The QV-10 also has a ton of features, which aficionados of little consumer-targeted techno-toys will expect. You can view images sequentially on the LCD screen (or composite monitor), or you can view mosaics of four or nine images for quicker reference and pick the one you want with a highlight bar. The QV-10 is also the only camera in this comparison to which you can actually upload pictures from a computer. There’s very little reason to do this with all of the other cameras, but the QV-10’s video capabilities make it a very, very portable 96 image digital slide show gadget, which you can connect to any display monitor or TV. Naturally, you can arrange the order of the images and the rate at which they are displayed (if you choose an automatic slideshow), and you can also set start and end points in a series of images. You can even get a 2x zoom on any part of an image. You can set the images you want to keep as "protected"; using the Delete All option then kills only the unprotected images. There is, of course, also a 10 second timer mode.

When the lens is pointed backwards it horizontally mirrors what it sees, so the composition of the image looks logical to you, but when the picture is taken the camera records the unmirrored scene, so everything’s the right way round. The Casio doesn’t have a flash, but it works as well as a consumer grade video camera in low light situations, and you can manually adjust its exposure, which compensates for its tendency to overexpose. There are two physical aperture settings - the indoor setting is equivalent to f2, and flicking a switch moves a pinhole piece in front of the lens to choke it back to f8. The fixed focus lens also has a macro mode, which pulls its 60cm regular minimum focal distance down to 14cm at F2, or 28cm and 10cm respectively at f8.

OK, now for the bad stuff. The QV-10’s image quality is, frankly, poor. The software lets you send images to your computer at up to 640 by 480 resolution, but that’s a load of hooey - the camera only actually captures 460 by 280 pixels and just duplicates pixels as needed to make up the numbers.

460 is an acceptable horizontal resolution, but 280 is way too low, and the notable compression artefacts make the results even worse. The Casio’s tone and colour balance aren’t fabulous, but it’s the awful image quality that stands out. Vertical and horizontal lines in pictures look all right, but diagonals exhibit drastic jaggies.

And if you’re thinking the lack of a flash will mean long battery life, though, think again - the LCD panel sucks enough juice to make a set of regular alkalines last for two hours with the camera in its playback mode, or a mere 30 minutes in record mode. Old-fashioned viewfinders, as sported by all of the other cameras in this comparison, don’t need power to work. Fortunately, you can run the QV-10 from a 6 volt plugpack. Unfortunately, one is not included - but it’s a worthwhile extra purchase for $39.95.

The only other serious problem with the QV-10 is that LCD panels are difficult to use in sunlight. It’s useable enough on overcast days, but bright sunlight washes out the panel almost completely. There’s a brightness adjust knob, but it doesn’t help.

With a bit of image twiddling, the QV-10’s pictures are fine for use as small Web page illustrations and in similar computer applications. But if you’re aiming for colour print use you’d better be happy with very, very small pictures. The QV-10 overall is pretty good, except for its resolution, which is very bad. If you’ve got an application that doesn’t need high res, the QV-10 would make a fine field camera. For happy snaps or specialised applications, it gives you a very portable, high capacity camera with very good image management right there in the camera. If only the images themselves were better.

The Casio QV-30 is the bigger brother to the QV-10, and it has a 2.5 inch screen instead of the 10’s 1.8 inch unit. Aside from that, it’s much the same - the QV-30’s resolution is just as bad.

 

Kodak DC20

The Kodak DC20 is very, very small - 31mm by 102mm by 61mm. It is also by far the cheapest camera in this comparison. And, for the money, it’s not bad.

For $560, you unfortunately can’t expect too much. The DC20 has no flash, and can only hold eight high resolution 493 by 373 pixel images or 16 320 by 240 shots in its unexpandable 1Mb of memory. You cannot mix resolutions and the resolution mode can only be changed after erasing all of the pictures. There’s no LCD display; the camera communicates with you via three LEDs and has only three control buttons. The lens is a 47mm-equivalent fixed focus, and works from 50cm to infinity, with no macro mode. There’s no individual image delete option, on the camera or via the PC or Mac software - when you delete images in the camera, you delete all images in the camera, full stop.

Image quality from the DC20 is also not very exciting. Not awful, and not bad considering the price, but certainly not up there with cameras twice the price. The images don’t show any compression artefacts and tone balance is good (no dark whites or light blacks), but the DC20’s colours generally look washed out and it’s prone to badly underexposing dark subjects in front of light backgrounds - there’s no way to adjust the camera’s automatic exposure. In low light, the DC20 tries to make up for its lack of a flash with double exposures, and the results are no better than you’d expect. Apparently a flash accessory’s on the way, but there’s no firm date for its arrival. Other accessories promised are an AC power adaptor and extra snap-on lenses.

Physically, the camera’s small size is matched by very light weight - if you judge your gadgets on grams per dollar the DC20 will score badly. There’s no standard quarter inch tripod screw hole in the bottom (all of the other cameras in this comparison have a tripod mounting hole), so you pretty much have to use the DC20 handheld, and it’s so small and light that it can be tricky to hold it still.

The DC20’s only way of transferring images to a computer is via a TWAIN driver, but it also comes with PhotoEnhancer Special Fun Edition, which works with the TWAIN driver and offers various "consumer" level image enhancement options, which are essentially a load of minimally configurable presets. You can pick from a few levels of options like "sharpen" or "brighten", or choose settings like "outdoors - overcast" or "indoors - fluorescent" and the software tweaks the image appropriately. PhotoEnhancer does more good than harm, but you can get notably better results with "proper" image processing software.

The DC20’s software CD also contains a slideshow program that lets you add captions and music to your displays, but the best bundled program is a special version of Kai’s Power Goo, the entertaining and exceedingly well done image distortion and morphing toy from Metatools, the makers of the enormously successful Kai’s Power Tools series of image processing plug-ins. Goo is minimally useful for pro image processing - although it deserves a place as a sort of "standalone plug-in" - but it’s a bunch of laughs to play with.

Unlike all of the other consumer cameras in this comparison, the DC20 isn’t powered by AA cells. It uses a single K123LA 3V lithium cell, which is quite commonly available and should last well in the flashless camera.

If the DC20’s resolution’s good enough for you, and you can stand taking a maximum of eight high quality pictures at a time, this is the digital camera that’ll put the smallest hole in your bank balance.

 

Chinon ES-3000 and Kodak DC50

The Chinon ES-3000, also available with different software as the Dycam 10C, is an earlier revision of the Kodak DC50. It’s physically almost the same as Kodak’s camera - a white case instead of black - and the similarity continues in most of the features.

Both cameras have the same autofocus 3x power zoom lens, with 7 to 21mm focal length (equivalent 38mm to 114mm in 35mm cameras). A zoom lens is a common enough feature in cheap film cameras, but the Chinon/Kodak pair are the only consumer digital still cameras to offer one.

Both cameras also have the same basic features - auto, always or never flash setting, single or multipoint autofocus (so you can easily focus a scene with nothing at the right distance in the middle of the frame), focus locking, a 10 second timer, macro mode, a viewfinder with compensation boxes for close-up and macro shots, manually adjustable or automatic exposure and a PCMCIA memory card socket instead of the proprietary, or nonexistent, memory upgrade systems used by other cameras. The LCD panel on the back of each camera looks different but has the same functions.

The Chinon’s maximum image resolution, though, is 640 by 480. It has two quality settings at that resolution, fine and superfine - superfine uses lossless compression - and a 320 by 240 "standard" resolution as well.

At maximum quality, you can fit only five superfine, 10 fine or 40 standard resolution images in the 1Mb of internal memory. Fortunately, the ES-3000 comes with a 4Mb Flash PC PCMCIA card, which extends the image capacity to a more reasonable 26, 53 and 212 images respectively.

The Kodak version of the camera offers slightly higher resolution but doesn’t come with the extra storage. The DC50’s only available resolution is 756 by 504 pixels, but it has three levels of image compression at this resolution. It can fit seven images into the standard 1Mb RAM in its "best" quality mode, 11 images in "better" mode and 22 in "good" mode. Good mode isn’t, actually, very good; the compression artefacts are highly noticeable. It’s fine for undemanding applications, though. Better and Best modes are much more attractive, and you actually have to look pretty hard to spot the difference. Tone and colour balance are good in all modes.

The DC50 comes with the full version of PhotoEnhancer. The differences from the DC20’s Fun edition are not sufficient to tempt anyone away from a professional image processing package, but it’s capable enough for basic colour and light compensation.

Both cameras run on four AA cells. If you use lithium cells (twice the price, three times the life) you should get about 800 shots, half with flash, which is excellent battery life. Alkaline batteries should be good for about 300 shots, good NiCd rechargeables for 200 or so.

The PCMCIA memory cards, now correctly called PC cards but more commonly referred to by the old name, give the ES-3000 and DC50 a way of very quickly transferring images, provided you have a computer with a PC card slot. Practically no desktop machines have PC slots - though you can buy PC adaptors that fit in standard drive bays - but they’re par for the course on laptops.

If you’re using an ES-3000 or DC50 with a memory card, it stores images on the card before it fills its internal RAM. This means you can squeeze off the card’s capacity of pictures (mixing resolutions as you wish), then pop out the card, pop it into the laptop, run the software that also lets you transfer images via old-fashioned serial link and copy the pictures onto your hard drive in a trice. If you’ve got pictures in the camera’s internal memory as well as on the card, all you have to do is delete some or all of the images on the card and pop it back into the camera and whatever pictures will fit are automatically moved to the card. You can use cards up to 16Mb capacity, or as small as 2Mb.

The card format isn’t standard, so you need the special software, but this is by far the most elegant way of transferring images from camera to computer, beating the SCSI-interfaced cameras handily. PC card data transfer is a selling point for far more expensive digitals. If only more desktop computers had PC slots.

The DC50/ES-3000 pair are deservedly popular. Good image quality, zoom and easy expandability are the standout advantages; the Chinon’s notably better value with its lower list price including a 4Mb card, but the Kodak makes somewhat better pictures. If you’re thinking of buying the DC50 but don’t need the zoom or the PC card expansion, consider the older DC40, also sold as the Logitech Fotoman Pixtura. It’s got the same basic imaging hardware as the DC50, but costs better than $400 less, and comes standard with 4Mb of RAM, enough for 48 high res pictures.

 

Apple QuickTake 150

The QuickTake 100 started the cheap digital camera avalanche, and its successor is deservedly popular, being (relatively) cheap and easy to use.

The QuickTake 150 offers the same 640 by 480 image resolution as its predecessor, but can store twice as many images - 16 high resolution images or 32 low res in its unexpandable 1Mb of memory. The focus-free lens is the equivalent of a 50mm on a 35mm film camera, and it focuses down to 120cm. For closer shots you can clip on a special adaptor that comes with the camera, which gives you a macro mode for subjects about 30cm away. It adjusts the lens, diffuses the flash and shifts the viewfinder view over so you get correct framing when you’re a foot from the subject, which is pretty impressive for a piece of plastic. You can’t turn the camera off when the adaptor’s fitted, because the 150 uses a sliding lens cover switch.

The QuickTake 150 has the usual timer function and auto/always/never flash setting, but that’s about the end of its photographic features - no manual focus, no exposure adjustment.

You get basic image transfer software with the Windows version of the camera but nothing else; the Mac version also has PhotoFlash 2.0, another in the long line of unexciting image manipulators.

The QuickTake runs on three AA cells; if you use lithium cells you should get around 200 pictures per set. The pictures themselves are OK, considering the camera’s price; as with the Epson PhotoPC, 16 640 by 480 images into 1Mb of RAM means less than immaculate image quality. But, again, they’re fine for any application that doesn’t need more resolution.

The QuickTake has the advantage of popularity; you can get clip-on lenses for it from third parties (all of which, of course, make the viewfinder hopelessly inaccurate) and there’s even a QuickTime VR tripod head for the camera from Kaidan, so you can automatically snap shots of an area and stitch them into a QuickTime VR environment. The Kaidan gizmoes start at something like three times the price of the camera itself, though. Apple also have a couple of QuickTake accessories - an external battery booster pack and tough carry cases.

If the unexpandable memory doesn’t scare you, the QuickTake 150’s a good camera for the money. If you need more pictures, the Epson PhotoPC’s the nearest contender.

 

 

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CCDs decoded

Every camera in this comparison uses one or more Charge Coupled Devices (CCDs) to create its images. All but the Agfa/Minolta heavyweights at the top of the price scale have only a single CCD - the big boys have three, not unlike top-flight video cameras. What’s the difference?

A single colour CCD, as used in consumer camcorders, has a resolution of 600 by 450 pixels. This is 270,000 pixels total. But it does not have 270,000 red pixels, 270,000 green pixels and 270,000 blue pixels. If it’s a plain vanilla sort of CCD, it probably has 90,000 pixels for each colour, arranged in horizontal or vertical stripes of the different colours.

Yet this CCD, which can only produce a 200 by 150 pixel image in any of the primary video colours, produces a 600 by 450 colour image, which isn’t composed of interleaved stripes of colour. It does this by means of interpolation - figuring out what colour each pixel should be based on what it knows about the one colour that pixel really detects and the colours really detected by the pixels around it. This system works, but it is of necessity not as accurate as a hypothetical magic full colour CCD where every pixel detected red, green and blue.

Unfortunately, hypothetical magic full colour CCDs don’t exist, but there are several techniques used to improve image quality. The dumbest of these is simply to make the CCD bigger and/or denser, so you’ve got more pixels to play with. This is all very well, but as soon as you stop using the cheap mass-produced video camera CCDs and decide to go for a proprietary unit the loss of economies of scale spikes the price up notably. Add to that the fact that larger CCDs have exponentially higher manufacturing failure rates, and it rapidly becomes apparent that super-resolution single chip designs, while technically possible, rapidly become hideously expensive.

A more lateral way of boosting CCD resolution is to vary the ratio of filter colours, so there’s more green and less red and blue. Since green comprises 59% of average luminance, it makes sense to give it a larger share of the samples. Kodak’s DCS Professional digital cameras use a 2:1:1 ratio of green to red to blue pixels, for instance. This makes the interpolated picture about as good as it’s going to get, but fine detail can be spoiled - interpolation is another word for guessing what the right value should be.

Once you’ve got your pixel colours optimal, though, the next step is to increase the number of CCDs. Going to multiple CCDs allows you to use low resolution (read: cheap) CCDs, yet achieve higher resolution - the incoming light is split between CCDs, but they can be treated as if they’re interleaved like a single chip design, and the same sort of interpolation applied. Pixel colour weighting can be used in multi-chip cameras, too; the Agfa ActionCam/Minolta RD-175 uses two offset green CCDs and a red/blue combo chip.

For very high resolutions, though, you have to abandon the ability to grab the whole scene in an instant. The less extreme way of grabbing high resolution colour is the three-exposure strategy, familiar to anyone who’s got a three-pass scanner or got into video digitising when a security camera and a spinning colour filter wheel was where it was at. The idea is simple - do away with the tiny filters on the pixels and use the whole CCD for red, then for blue, then for green, using a big filter for each colour. Three shot studio cameras can work with conventional flashes (three shots) and can thus take pictures quite quickly, though not of moving objects.

Want more resolution per dollar? Can do.

A CCD that genuinely captures a 6000 pixel square image costs a fortune, even for a monochrome version. But a trilinear CCD array such as is used in a single pass flatbed scanner can capture a 6000 dot wide colour image one line at a time for a lot less. In digital photography, this is done by putting a scanner array in the back of a large-format studio camera. Unfortunately, scanning-back cameras, as they’re called, can take minutes to photograph a scene, which makes them utterly useless for action photography or subjects that don’t like being brightly lit for that period of time. Conventional flashes are no good.

Ingenious design can allow humans some input into the interpolation process, which scanning back cameras still have to deal with. Leaf’s Catchlight studio camera has four different coloured filters in a random pattern on the scan head. The user can choose from four interpolation algorithms and see which one makes the shot look best.

If you don’t need colour (hello, Artistic Photographers!), all of the digital studio cameras can accommodate you, and often with better resolution than they can manage in colour.

Dicomed’s BigShot 4000, built on a Hasselblad body, might provide a glimpse of the future - it’s a three-pass camera that uses a superfast liquid crystal filter (removable for monochrome) to take three 4000 by 4000 exposures fast enough for use with a single flash. It sells for a mere $US54,900, but the technology is likely to trickle down.

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Photo CD - bridging the gap

What do you do if you’ve got 35mm photo gear, but need digital images, with resolution as good as film? You scan your negatives or slides, that’s what.

Doing this yourself requires the purchase of a drum scanner that costs as much as four Ford Lasers, so most people have their scans done at a bureau. There, a scan of a 35mm shot for use in a 200dpi A4-sized print application will cost you something in the vicinity of $50. But there is a cheaper way.

Kodak Photo CD was invented as The Consumer Photography Way Of The Future, but the designers’ dreams of families gathered around the Photo CD player have yet to be realised and probably never will. People like photos in photo albums, and it’s hard to persuade them to pay more for processing and buy a player so they can view their snapshots on their TV. Home computer users have also failed to flock to Photo CD, preferring to digitise prints with cheap scanners at home. But despite its failure in its initially conceived role, Photo CD is a really useful format for professional applications.

Photo CD writing, as envisaged by Kodak, is an extension of traditional film processing. You take your film to the chemist and after paying a bit more and waiting a bit longer you get the pictures on CD. Most Australian film processors may give you a blank look if you ask for Photo CD, but DTP bureaux understand it and a quick ring-round of your nearby purveyors of DTP services will probably unearth a local solution.

Standard Photo CDs contain each image in five resolutions - 128 by 192, 256 by 384, 512 by 768, 1024 by 1536 and 2048 by 3072. Even when processed at consumer quality, these images generally need little manipulation to be useable in professional applications, and 2048 by 3072 is big enough for A4 print reproduction.

The quality of Photo CD scans is generally very high, though not necessarily quite as good as a professional drum scan. If you’re using consumer grade Photo CD then the limiting factor is generally the quality of the film processing before the scanning process, and idiosyncrasies there are often easy to compensate for digitally. Mind you, since Photo CDs can be written by anyone with a CD writer - they’re just files of a particular format in a particular directory structure on a standard CD-ROM - you can have drum scans saved as Photo CD. It’s all up to the people making the disc.

The price of image transfer varies, and the small number of Australian companies handling Photo CD processing doesn’t help, but you’d be unlucky to find a deal that cost you more than half of traditional scanning rates. Around 100 images fit on a $20 disc, and you can fill the disc up in as many separate sessions as you like. The convenience of having your images automatically CD archived with handy printed contact sheets should not be understated.

If consumer processing isn’t good enough for you, the recently developed Pro Photo CD standard fills the gap. It adds a new 4096 x 6144 resolution, which is about as good as you can get from 35mm film. Pro Photo CD also supports other film formats - 120, 4 by 5 inch and 70mm. Expect pricing around $20 per scanned image at full resolution.

If you need the images right now, Photo CD isn’t for you, even if you own a money tree and can do it yourself. But if your deadlines aren’t that strict, your trusty film camera and a Photo CD bureau can beat the pants off a $100,000 digital wonder-cam.

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Photographic terms

We’re computer people. We don’t understand this weird photo-jargon. If you’re like us, here’s a quick glossary of the basic photographic terms you need to understand to make sense of digital camera specs. Read it when nobody’s looking so you’ll look more knowledgeable when they are.

Aperture: The size of the hole that lets the light through the lens and into the camera. The larger the aperture, the more light gets through.

F stops: The F stop or f-number of a lens is the focal length divided by the aperture, and it indicates how much light is actually getting into the camera. The brightness of the image on the film - or CCD - is inversely proportional to the f-number squared.

Focal length: Lenses are referred to as being of x many millimetres. A 60mm lens, for instance, produces an image of a distant object on a camera’s film or CCD that’s the same size as the image that would be projected by a pinhole 60mm from the film or CCD. Longer focal lengths give more magnification, but let less light into the camera.

All but the most expensive digital cameras have image acquisition areas which are smaller than the area of a 35mm frame. This means that the "consumer" models’ lens focal lengths are equivalent to larger focal lengths for 35mm cameras - the 7mm focal length of an ES-3000’s lens zoomed out all the way is equivalent in field of view to a 38mm lens on a 35mm camera.

Most digital cameras with 35mm fronts, like the ActionCam/RD-175, also have CCDs smaller than 35mm film. To allow them to use 35mm film lenses, they have extra optics inside the camera to focus the oversized image onto the small CCD. The extra optics increase the effective focal length of lenses; a 50mm lens on a Minolta RD-175 will have the same field of view as a 100mm lens on a regular film camera.

Shutter speed: How long light is let into the camera to form an image. The slower the shutter speed, the more light gets in, but slower settings also make moving objects more blurred. Digital cameras don’t need to have a physical shutter, though some do.

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For and against

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<Feature review on its own page>

SNAPPY! The analogue alternative

Brilliant high resolution images captured from video? It sounds impossible, but this neat alternative for PC owners demonstrates new technology had turned video into a worth while alternative to digital still cameras.

 

A common garden variety video camera can also be used for digital image acquisition - but you have to buy a video digitiser. There are a variety of video acquisition systems out there - high powered non-linear video editing boards can be used for the purpose, but there are a number of cheaper options. If you grab from a live camera image, the image fidelity can be very good. Obviously, the better the camera the better the image, but even cheap consumer cameras can deliver impressive results if the subject is correctly lit.

The current front-runner in the cheap video grabber market is Play Incorporated’s Snappy Video Snapshot, which has recently become available in a reworked PAL model to suit Australian video. The Snappy is priced to suit consumers’ pockets but is still capable of superb quality grabs, and it’s swept the field in the USA.

The Snappy plugs into a PC’s parallel port (sorry, Mac users) and accepts composite video input from whatever source you like - with a passthrough port for monitoring the signal. If you want to use a parallel printer as well you’ll need to swap plugs or get a switch box, as there’s no printer passthrough. The Snappy’s powered by an internal 9V battery, which is said to last for better than 1000 snaps and might well do so, because the Snappy’s intelligent about powering itself down when it’s not needed.

The 3D interface is both attractive and easy to use - unlike many cute "consumer" interfaces, it has useful keyboard shortcuts - and previewing video, setting resolution and image correction and actually grabbing images is easy. There are modes for grabbing from moving and still video (still gives better results) and the Snappy hardware and software does a surprisingly good job of cleaning up lousy video input.

The Snappy’s software allows considerable enhancement of grabbed frames. No changes are actually made to the grabbing process, so you’ll probably do better by saving the raw grabs and manipulating them in Photoshop or the package of your choice, but the all-in-one design of the Snappy interface suits it perfectly to its intended consumer market. The most generally useful enhancement for grabbed frames is sharpening, since the high resolution grab of fuzzy video leaves considerable room for a well applied unsharp mask. The Snappy also tends to produce slightly dim images, a flaw easily fixed with manual or automatic histogram equalisation.

Snappy goes notably beyond standard video resolution; it offers a maximum capture resolution of 1500 by 1125 pixels. This resolution is almost twice the popularly quoted size of overscanned video.

The reason for the high resolution is fairly simple - Nyquist’s Theorem states that an analogue signal must be sampled at twice the bandwidth occupied by the signal for analogue-to-digital conversion, which is why the sampling rate for audio CDs is 41.5kHz when the highest frequency they reproduce is around 20kHz. The same principle can be applied to video digitising - to get all the available data, you have to grab twice as many dots as the image quality would appear to provide. But it hasn’t been, at least not in affordable devices, until now, because the hardware didn’t exist.

What all this means is that a hypothetical conventional digital camera whose CCD has exactly the same number of pixels as the Snappy’s maximum resolution pictures would, all other things being equal, give better results. The Snappy may well have a custom-made HD-1500 digitiser chip and do all kinds of funky interpolation tricks on the software side, but it is still not capable of making something from nothing. The still camera would be directly looking at the scene and making dots from the incoming light, whereas the Snappy is sampling as best it - or anyone - can from a low quality video feed.

The fact that it’s working from composite is the Snappy’s only weakness. It produces remarkably good results when you take the low quality of the original signal into account; Snappy grabs from a good quality video camera are certainly up there with the output from consumer grade digital cameras. If all you’ve got is a cheaper video camera (VHS, VHS-C or 8mm), the Snappy’s results are limited by the low grade of the image acquisition hardware - which only needs to be good enough for VHS. A high band camera, though (SVHS or Hi8), produces notably better composite output.

But the Snappy can’t compete with "pro" digitals, no matter what video source you use. Future enhancements may allow the Snappy to work from Y/C video, which should improve the results further - it has an as-yet-unused five pin expansion connector. But it’ll never rival serious still cameras; the Snappy’s already pretty much as good as a video grabber can get, and the performance and pricing of digital still cameras is improving continuously.

For $400-odd, though, the Snappy is a superb alternative to a $1000 dedicated still camera, if you’ve already got an IBM compatible and a video camera. If you’re a gadget lover, which is the major market for digital still cameras, you probably do already have both of these other items, unless you blew your spare cash on a model helicopter.

 

Quality versus quantity

The advantage of grabbing from video is that you can take a chunk of video of a subject, twiddling exposure settings and trying different framing and angles, and then reviewing the footage later to decide which frames to actually grab. A video viewfinder, on all but the very cheesiest cameras, gives you a good idea of what the camera’s really seeing. You know if the focus is off. You know if the exposure’s all wrong. You know if the lens cap’s on. There’s also no sweating over the shutter button waiting for the interesting even to happen and knowing that you’ll only get one go - just tape a minute of footage on either side and extract the good bit at your leisure.

This is one of the notable weaknesses of current digital cameras - the couple of seconds of processing time between pictures on even the premium models makes them useless for the traditional photojournalist’s speedy sequence of shots. Nobody’s going to pay for one shot of the diver leaving the board and another of him swimming for the ladder.

In the near future, Digital Video (DV) cameras will hybridise analogue video grabbing and digital still photography, as DV has a standard still frame mode that puts 500 good quality stills on a 60 minute tape, each still accompanied by seven seconds of audio which can be used for labelling purposes. The image resolution will still be well shy of better dedicated still cameras, but should surpass cheaper models, and the incorruptible digital image means you won’t need a live picture to get optimum quality.

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Going pro

Professional quality digital cameras used to cost a large fortune. Some of them still do. But pushing down into small fortune territory are the Minolta RD-175 and its rebadged clone sibling, the Agfa ActionCam.

$12,000’s a lot to pay for a camera with only one lens, but that’s about what you’re looking at for either of these cameras. The two cameras are precisely identical in everything but price, stickers and software opening screens, but since Minolta actually make the thing I’ll use their name.

The camera is based on a Minolta Maxxum/Dynax 500si AF 35mm body, very similar to the 400si film camera. It accepts the lenses and accessories that the film version can use, and this feature alone blasts it far ahead of its cheaper semi-pro competitor, the Polaroid PDC-2000. It comes with a 28-80mm AF zoom lens, and supports shutter speeds from to 1/2000 second.

While the RD-175 can be used as a full-auto camera, less experienced photographers will be glad to know that it also has an auto mode that’s smarter than Lassie and can generally be relied upon to produce professional results, with automatic adjustment of focus, exposure, white balance and flash. A flip-up flash is built in, but there’s also a hotshoe and PC-flash connections; you can use the RD-175 to trigger extra Minolta flash systems and set its exposure from the total light intensity.

For a bit more control you can use shutter or aperture priority, where you set the shutter speed or aperture and the camera automatically adjusts the other variables. No matter which mode you choose, shutter speed, aperture and date information is stored with each image.

The autofocus system is very fast and very accurate, using bursts of flash illumination to get focus in low light conditions. The camera won’t take a shot if it thinks it’s out of focus, though, and so the only time most users are going to have to turn off autofocus is when shooting a difficult low-contrast subject that the autofocus just can’t get a handle on. In manual focus mode, the red/green viewfinder focus indicator continues to function as a rangefinder.

The RD-175 runs from a standard 6V lithium ion rechargeable battery, as seen on classier camcorders, which is good for more than 100 non-flash photos. The one hour charger supply can charge a battery OR run the camera but not both - a flaw it shares with camcorder chargers - and so a standalone charger could be a wise extra purchase.

The RD-175 is a three chip camera, against the single CCDs in all of the other models. Three chip used to mean a red CCD, a blue CCD and a green CCD, but since green comprises 59% of average signal luminance, it makes sense to devote two CCDs to green and stripe the remaining one with red and blue. The RD-175 does this, and offsets the two green CCDs by half a pixel diagonally so that its three 768 by 494 pixel CCDs give it an effective resolution of 1528 by 1148, with ISO 800 sensitivity.

The compensatory optics in the RD-175 that focus the image down onto the CCDs double the effective focal length of attached lenses, and make the widest possible f stop f5.7. The viewfinder is a full-field design which, like the finders in some other pro cameras, shows 90% of the frame. A 100% viewfinder suits some users better, but both designs are better than the finders in some pro digitals, which aren’t compensated for the telephoto effect of the extra optics and thus show 200% or more - with or without a central box to indicate what you’re actually going to photograph!

The RD-175 uses PC cards for storage - presently, the only storage option is PCMCIA 3 hard drives, not flash RAM cards. A 131Mb drive is standard and holds 114 images; you can swap in more drives as needed for extra storage.

When purchasing extra drives for an RD-175 or ActionCam, get them with a guarantee that they’ll work with it, since the camera is reportedly not compatible with all brands. And don’t expect to be able to unplug the drive from the camera and plug it into your laptop; the RD-175 uses a non-standard MS-DOS-ish disk format which isn’t compatible with many systems and is only partially compatible (read only) with others. Fortunately, the SCSI interface and TWAIN driver is speedy enough that only serious bulk image users will find it less convenient.

In the software department, the RD-175 and ActionCam are obviously meant for people who already have image processing programs. And are using Macs. If you’re a Windows user you get a TWAIN driver, and you should be grateful for that. For the Mac, however, you get Photoshop LE (in case a big guy with a gun swiped your copy of the proper version of Photoshop), a Colour Management System package called FotoTune and a colour correction plug-in for Photoshop called FotoFlavor.

In use, the RD-175 is notably larger and heavier than a standard 35mm camera thanks to all the digital extras. Lengthy hand-held shoots can be fatiguing - it’s 900 grams without a lens or battery - but the ergonomic design of the camera is still excellent, with all important buttons conveniently under the fingers when the camera is held two-handed. And 900 grams plus lens is pretty light for a pro digital.

The camera’s pro features come with one annoyance - there is absolutely no in-camera image management. You can overwrite the last image you took, but you can’t delete one or all images, so if you fill a drive and can’t get near your computer, you’d better have another drive. If you absent-mindedly transfer all the images from a drive, forget to delete them and then take the camera out again with the same drive, you’re stuffed.

But the image quality can’t be beaten, except by cameras costing a great deal more. The RD-175/ActionCam is a product that deserves to do well, because it provides most of the performance of the traditional alarmingly expensive digitals at a small fraction of their price.

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The final analysis

If you’ve got your heart set on a digital camera, practically everything in this comparison has something to offer. The DC20 does the job for happy snaps and undemanding Web page use. The Casio QV-10 has its uses as a super-portable low res 96 image video slide show unit that happens to be able to take pictures, too. The Epson PhotoPC is a decent basic digital camera for the money, but the Apple QuickTake 150 edges it out if you’re not interested in more than 16 high res images at a time. The Chinon ES-3000 and Kodak DC-50 run pretty much neck and neck; they share the same useful zoom and PC card convenience, but the Kodak wins on image quality and the Chinon wins on price. The Polaroid PDC-2000’s a great digital camera, but not necessarily for the money - line it up against the far more featureful Agfa and Minolta cameras and you realise that it may be half the price, but it’s a tenth as capable.

When it comes to bang per buck, these big boys rule the roost. $12,000 is of course a lot more money than most digital camera purchasers would dream of spending, but professionals will be used to raising their eyebrows at prices five or more times higher and these relatively cheap cameras look like bargains by comparison.

But digital photography is a long, long way from being a mature technology, and Photo CD and video grabbing offer solutions that are, respectively, higher quality and much more cost effective. If you want a low-end digital camera but already have a PC and a video camera, the Snappy is almost certainly a better idea. And if you want professional quality, whether or not you already have a film camera, 35mm and Photo CD is a heck of a lot cheaper - provided you can stand the wait.

 

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