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Compared to traditional photography with its film and developing costs, taking digital photographs is essentially free. So immense numbers of images are taken by photographers. This leads to the need for image management . . . Part 2: Hints, tips and traps – By Kevin Poulter The Electro W hen memory cards first came out, their capacity was measured in megabytes – and not very many of them! Today, they are 4 Gig or even larger, capable of storing 600 to 1000 high-res, high-quality images. Keen photographers then have vast files needing uploading to a computer hard drive. From there, the photographs are normally transferred to CDs or DVDs for archiving. But many images are retained on the hard drive for enhancement and start taking up bulk space – so soon another drive is required. Unless you install another hard drive in your system, the usual choice is a USB drive, which as its name suggests, simply plugs into a vacant USB port. The computer detects the new drive and assigns an ID to it. Normally this is pretty painless but sometimes results in confusion for the disk and computer, especially (for example) if you also use other removable drives and are forever plugging and unplugging them. In a rush, the drive can be unplugged before all the data is written. At minimum, the data can become corrupted. Worse, hard drive failure (crash) may result, with all data lost – and I speak from sad experience. When this happens, you 28  Silicon Chip can try various data recovery methods; you can accept the losses or if the images are worth it, involve a specialist recovery company at a cost of $1,000 to $2,000. In most cases, the drive itself is a write-off. Even though you may get it to work, our experience is that once a drive has crashed, it’s likely to do it again. It may just lie there doggo, waiting until you have particularly important images stored on it . . . Until you or your computer dealer has tried all conventional restoration methods, like repair software, don’t assume all the data is lost. Disk recovery businesses try their powerful repair software too, and if that fails, the hard disk platter may be physically removed, then installed in a good drive in a totally dust-free environment. A new directory and device driver must be written onto the corrupted disk, so some data can be lost but most times most data is recovered. Needless to say, this is not a cheap process! Plan ahead and archive! To avoid this drama, the solution is to plan ahead – siliconchip.com.au onic Camera regularly copying the images on the computer’s drive to CDs or DVDs. You can even bypass the hard drive and save directly from camera to CD. This is achieved by connecting your camera to the computer, launching disc-burning software, then dragging the camera’s image folder to the CD burner window. You won’t find this idea in computer magazines but it works. As it’s not a mainstream technique, try it first with a number of non-essential images. Large numbers of archived CDs and DVDs can be kept on the CD posts that come with CDs sold in packs of 25, 50 or 100 units, or in a disc stacker. Because they are optical, not magnetic, there will be no “bleed through” such as you can get with floppy disks. But for valuable archive CDs containing irreplaceable material, it is better to store them in their own cases. Great care should be taken to avoid fingerprints, scratches and marks. If a disc needs cleaning, never clean it in a circular motion: digital discs should be cleaned in a straight line from centre to edge, like cart wheel spokes, DVDs are such precision technology with ultra-fine siliconchip.com.au A LaserDisc with impurities eating the tracks away. On a good player, the picture jumps a little, but if this was a CD, data would be lost. This is a good reason for choosing leading brand CDs for archiving. April 2006  29 In sunlight and other extreme contrast situations, film and digital cameras struggle to cope with the brightness range. With digital, one tip is to set the camera on low contrast but this may still be not enough. This awning always faces into the light, so no clear photograph is possible. The solution – bracketing, or two images, (one light, one dark), photographed on a tripod. Both were then placed in Photoshop, exactly on top of each other. Then the best exposures were kept and the extreme light and dark areas removed. The result appears normal but in fact has far less contrast than the original scene. tracks, they have more problems than CDs – like incompatibility between machines. We’ve seen a DVD made on a computer, which then refuses to play it . . . but that DVD works on another machine! And there was another DVD made on a ‘stand-alone’ recorder, which when played in a computer caused a crash. The format detail wars like DVD-R and DVD+R have also caused incompatibilities. Generally, use DVD-R for maximum compatibility between DVD players, especially older machines. With the advent of iPod and other multipurpose devices that store to memory cards, it’s only a matter of time before cameras will store music and other data. Oops, too late – they do it already: multi-purpose cameras are now beginning to appear. Imagine the versatility of a camera with a built in voice recorder for journalists, plus music, radio and movies. And of course we have many cellular phones with cameras inbuilt (although with some of the latest multi megapixel models you have to wonder if they aren’t cameras with phones inbuilt). Most of these newer models have either a large (>1GB) flash memory or have the same in removable memory card (often SD, MMC, RS [reduced size] MMC, etc). Already, nearly all cameras allow images to be loaded back to their camera card after saving in your computer, so it would seem logical to upload other types of data files too. Our test showed this works. We have saved Word documents to the camera card but when we asked camera technicians in Japan if there was any reason why it couldn’t be done, there was a hasty, rather excited reply from the designers – “reformat your card immediately – you will break it!” Well, I don’t do it any more but I know plenty of people who do. And to my knowledge, they haven’t “broken it” yet! Into the future? Theoretically (and unlike film which will deteriorate), digital images should print exactly the same quality in a century as the day they were photographed – although we have yet to see any storage medium, card or disc, guaranteed anything like that long! But scaremongers say “what if in only ten years, .jpg ceases to be the universal format, making the images useless?” This appears unlikely, as countless billions of images have been saved in the JPEG format. At the very least, we would expect there to be conversion applications to open JPEGs for years or decades to come. JPEGs themselves will almost certainly change over time as the Joint Photographic Experts Group continues to evolve and develop the JPEG standards. It’s much more likely that in ten years you won’t find a CD or DVD drive to handle your discs – how many 8-inch or 5.25-inch floppy drives do you see these days? Even the ubiquitous 3.5-inch floppy drive of a decade ago is no longer fitted to most new machines. Unfortunately, the compatibility and longevity of storage media like DVD and CD-R is less assured. With some CDs priced at less than 20 cents, it’s no In graphics applications like Photoshop, there are surprise. many methods to enhance image colour, contrast, Imaging companies’ brightness and detail. On the left is “Curves”, a contrast control for each colour channel. But the reports on data integrity easiest to use is ‘Variations’, as many copies of the image are displayed with the expected result. 30  Silicon Chip siliconchip.com.au stored on CDs range from no failures due to ageing so far, to one experiencing media problems after just two years! For long-term image storage, it’s advisable to save files onto two different leading brand CDs or DVDs, then store the discs in a dark cupboard. For valuable/irreplaceable images, controlled temperature/humidity storage could be an option. Additional image security is possible when there’s room to save two duplicate copies of an image folder on each of those discs. Use two (and different) quality brands like Sony, TDK, BenQ or Imation, not the bargain store cheapies. Also consider recopying irreplaceable image discs, every five years or so. One other source of potential damage is the ink in pens used to label CDs and DVDs. There has been at least some research suggesting that the chemicals within the ink are likely to do more damage to the CD/DVD over time than anything else. Photoshop before printing! Printing digital camera images is becoming much easier, with print booths in most shopping centres, but unless you are ordering batches of full-frame postcard-size happy snaps, this can be time-consuming. Digital photography cries out for enhancement – and much improved images result if they are processed first. You can crop, sharpen, correct colour and contrast, enhance detail, title, even remove or mask objectionable features with a little knowledge of graphics applications like Photoshop. In business . . . Digital cameras have a multitude of uses in electronics businesses, like sales, a portable colour copier, ideas seen at trade shows, recording the assembly of products and noting component types like plug configurations. Have you ever tried to explain a multi-pin plug type to a supplier? Send a digital snapshot via email and immediately they know the type you want. Digital cameras are perfect for insurance records too. A copy of all the images can be sent to an insurance agent on CD and/or kept off premises. When travelling by road, keeping a digital camera with you enables photography of events or even an accident. Its been proven people who have photographs of an ac- Professional photographers use a flash meter for perfect exposure – still essential in digital photography. The Pantone (PMS) colour swatch provides CMYK reference colours to compare to the on-screen images. siliconchip.com.au Here’s how we process the pictures you see in SILICON CHIP We’re often complimented on the standard of photography in SILICON CHIP. Needless to say, it doesn’t just happen! This gives you some idea of the numerous steps involved in processing our images – note that this is all after the photographs are taken! All our photos these days are digital. They’re taken with a 6MP Nikon D70 SLR camera and studio flash set-up. Here are typical steps undertaken to get each of those images ready for publication: [1] After shooting (perhaps 100 images + at a time) all images moved from the camera’s compact flash card to a dedicated (photos only) 200GB hard disk on the network server. We put them into folders whose names describe both the subject and the date shot (eg, fan timer 28-08-05). [2] Image files in that folder bulk-renamed to describe the subject (all D70 images are named DSC_ and four digits – not at all helpful in a month or two when you are looking for specific subject shots!) [3] The images examined and chosen frames downloaded to local computer for processing (it’s much faster than over the network). [4] Photoshop started and selected images loaded in – perhaps 6-10 at a time. [5] If required, image cropped to appropriate area. [6] Resulting image resized to final printed size and resolution reduced from 300dpi (ex Nikon) to 266dpi (printer’s requirement). The 10% reduction may seem to be not worthwhile but when you’re dealing with perhaps 100 or more pictures each issue, the saving in space certainly is! [7] Image adjusted as required using either levels, curves, brightness/contrast, colour balance, selective colour, variations, etc or any combinations of above (and more). This can take some time for each image. [8] If required, image is “deep etched” to remove background (using pen tool and paths/clipping path). [9] If required, image “despeckled” (filter/noise/ despeckle). [10] Image edges sharpened using “unsharp masking”. (filter/sharpen/unsharp masking). (If you don’t understand the term, which has been described as an optical illusion of an optical illusion(!), there’s plenty of descriptive information on the ’net.) Incidentally, we virtually never use Photoshop’s (or the camera’s) “sharpen” function because unsharp masking does a much better job. (11] Image converted to CMYK [image/mode/CMYK] colour. [12] Image saved as Photoshop EPS with JPEG maximum quality and 8-bit TIFF preview . Ross Tester April 2006  31 Sharpening (left to right): original, optimum, excessive. Sharpening images can make them appear very much clearer, as long as it is not extreme. Some subjects, like people’s skin, are best not sharpened, as people are not keen on supersharp lines, wrinkles and freckles. cident are in a much better negotiating position in case of a claim. And you never know when you might stumble across that one-in-a-million chance of a photo that media outlets with thick chequebooks will climb over each other to get! If you don’t have a camera, you will never know! The subject is the key Vast knowledge of photographic techniques is not the key ingredient for awesome photography. Subject matter is. Sure, advanced photographic knowledge is an advantage but here’s an example: try photographing a standard car, then a Ferrari in the same breathtaking location. People will rave about the Ferrari photograph, even if the standard car image took more effort and technique. Likewise, in business, image is everything. Many sales are generated purely from top quality images displayed in magazines, brochures, or internet sites, so hiring a professional photographer for top end images can be a wise investment in sales-building. Enthusiastic amateurs? Bean counters often decide to save money by convincing a manager to purchase a “prosumer” digital camera and then getting a keen amateur photographer employee to shoot products in-house. This usually results in lower A typical Studio Flash, with a floor pack (mainly a bank of large capacitors), counter-weighted boom, wheeled dolly, head and Sof-Box. The large reflector is silvered inside with parachutelike material on the outside to diffuse the light. This makes a strong, nearly shadowfree light, like a bright but cloudy day. The output power is huge, equivalent to strong daylight outside. Light power is adjustable, with a variable output control. This unit stands higher than a person and preferably uses a dedicated 240V power circuit. 32  Silicon Chip quality images, not to mention the considerable time away from their main job plus the extra cost of the graphic artist needed to rescue the low-res image (and perhaps the pro photographer needed to redo the shots!). The problem is, that keen amateur might have taken a few good shots at cousin Mabel’s wedding (but then again may not have!); however, invariably that person knows little or nothing about the many facets of commercial photography or even about processing digital photos for commercial use. Photoshop? What’s that? And it’s a rare photo indeed (digital or film!) than doesn’t need some work in Photoshop – and often needs a lot! Here’s a typical commercial digital photo shoot (on location or in studio) for an electronics manufacturer (yes we do still manufacture in Australia): (1) Studio flash units are set up. (2) A flash meter is used to test the level of flashlight in all areas. (3) Digital exposures are made. This may include various exposures and in sections, to make a high resolution composite. (4) A PMS or Pantone swatch is matched to essential colours. (5) Images are loaded into the computer. (6) Enhancement, including remove background, move to a generic (or printeraligned) CMYK canvas, with enhanced sharpness, contrast, colour – correct (to the Pantone reference) and repair any dust or marks. For the ultimate colour matching, the graphic artist aligns to the printer’s CMYK profiles and runs tests first. It’s a bit different to grabbing the camera out of the drawer, placing the object on the bench and shooting off a few images, isn’t it! Imagine a raw beginner being given this task – and what they’d end up with? Many of the steps, particularly the later ones, require critical judgement decisions, based on operator skill and experience. siliconchip.com.au out in just six months. Transformers and limit resistors simply get too hot. One solution is to install fans in older flash units, plus slowing shooting sessions. And there’s another problem: many studio flash units (particularly older ones) have a very high sync trigger voltage applied to the camera’s flash contacts. This can damage the camera and void the warranty. Back in the olden (film camera) days, flash contacts were mechanical and even those burnt out. Digital cameras invariably have solid-state triggering, with maximum flash trigger voltage ratings and polarities to worry about. Photographers may consider optical isolators when using older flash units (see references on web page). In fact, on the Nikon D70, there isn’t even provision for an external flash connection. To use a studio flash you need to buy a hot-shoe adaptor. Film vs digital quality In Photoshop’s ‘save for web’ mode, an option is blur. This enables smaller file sizes and in the example, reduces the dots from the printed image. This extreme enlargement shows the effect, however at normal viewing size, both images are acceptable. When scanning a printed image to be reprinted in a magazine, it needs to be de-screened (dots highly softened) as otherwise the existing printing dots clash with the new reprint and cause a moire pattern. In the news In other media, news reporters saw the advantage of digital cameras very early in their development. The ability to immediately load images to computers and to send them on the web or load to the next newspaper edition was vitally important. Initially they managed with 4 megapixel cameras, until higher resolution became available. These days 8MP, 12MP and even higher resolution cameras will be found in every press photographer’s arsenal. While digital cameras have been used by the news media for more than a decade, they really came into their own at the 2000 Sydney Olympic Games. A special edition of the Sydney Morning Herald, complete with closing ceremony photos was available outside the Olympic stadium as spectators left the closing ceremony! Studio flash units We mentioned a moment ago that SILICON CHIP uses a professional studio flash setup. But even that is not without its problems when it comes to digital photography. The sheer volume and speed of digital photography means equipment can burn out. Working with models, or even large commercial projects, digital keeps up with fast action. The problem is that mains-powered studio flash units were never designed for this speed. Prior to digital, they worked fine all day, every day, as film photography was so much slower and conservative. One Photo Studio we know had four flash units burn siliconchip.com.au How good are digital cameras, compared to film? Here’s where you can really get into an argument, particularly with died-in-the-wool film buffs! Results vary with the brand, pixels and oddly enough, the subject matter. Lenses contribute to the overall quality too. Digital cameras 4-5 megapixels and above can be as good as or superior to 35mm film for technical subjects. This is especially due to the sharpening possible in a digital camera. Sharpening is an algorithm that detects the edges of objects and lines, increasing the contrast between them. Restrained use of sharpening can work very well indeed. Excessive sharpening looks like a video recorder or TV with brightness and contrast set too high – noise and unwanted detail dominates. It just looks wrong! Judicious sharpening works so well, it’s possible to copy an old image, sharpen it and make a copy print that appears to be much better than the original. When photographing people on a digital camera, a resolution of 8 megapixels or more is needed to compare to film. The reasons why people need more pixels are obscure but include lack of high contrast pixel neighbours and the need for perfect, blemish-free skin. Digital tends to exaggerate marks like freckles. Not only that, skin tones are a universal yardstick. Everyone knows just how skin should look so it’s easy to spot when it’s wrong! Ideally people are photographed with the camera set to low contrast, low sharpness modes, then only the hair, eyes and lips sharpened. Many photographers shoot faces and then use gaussian blur to soften the skin but this looks very false. Modes and file size Of the digital camera file choices, RAW, TIFF, SHQ, and JPG, the best compromise between quality with modest file sizes is SHQ. SHQ stands for Super High Quality and is saved with “best” (or least lossy) JPEG compression. This results in significant file size savings. For example, a typical RAW file is 13.4Mb, and SHQ, which saves with the suffix .jpg, is 5.6Mb. JPEG works by ‘looking’ at adjacent pixels and discarding any that are very similar, to reduce file sizes. When opened, April 2006  33 on the viewing screen almost immediately as a somewhat fuzzy image and build progressively to the full quality image – that’s useful because web browsers, (as in humans, not the software), do not like to wait long looking at a blank screen. If they see something happening, they’re much less likely to click off. Resolution This studio photograph of pump impellers was merged with other images. The background is constructed from a photograph of clouds, with the edges darkened. the JPEG system restores the missing pixels. A photograph with less detail and large areas of even colour can save in JPEG as a particularly small file, as so many similar pixels can be discarded. Amazing file size reductions are possible, like a 2MB image saved as a 40kB file. At JPEG minimum compression, (12), the loss of image quality is barely detectable, however apply maximum compression and it’s quite noticeable. Saving and re-saving a .jpg results in losses every time, seen as less and less clarity, plus eventually very high noise. To avoid additive losses when working more than once on JPEG images, save the progressive images as .PSD or .TIFF – both have no detectable loss of image quality after many save and re-save steps. On your final image, save back in .JPG format. There are also no losses if a JPEG image is duplicated (copied) without opening it. Web images Web images must be saved as RGB (as distinct from CMYK) and in either .JPG or .GIF format (.JPG is most common). Photoshop can do this for you almost automatically with a special feature ‘save for web’. This shows a window with the original image and the compressed version side by side, plus the size the file will be saved at. The best compromise between quality and file size is the 60 setting, however some images will look acceptable with the 30 setting. Checking the ‘progressive’ box means the image will load As we showed last month, optimum image resolution, or dots per inch (dpi) is vital, as images with insufficient pixels look fuzzy. Conversely, excessive pixels gain no extra clarity and take immense amounts of hard disk space, while slowing, or even stalling printing at photo labs or to inkjet printers. If used on web pages, they slow them to a crawl (or worse!). For best clarity and to avoid large files with no extra benefit, save images with the following resolutions: Printing at a Photo Lab: 250 to 350 p/i (pixels per inch) Laser or Inkjet printers: 200 to 300 p/i Magazines: 266-300 p/i Websites and E-mails: 72 p/i These figures are often incorrectly quoted as dpi (dots per inch), the measure for dot frequency on the printing press. It is amazing how clear images look on the internet, considering they are only 72 dpi. In fact many giant advertising display billboards are also made from 72 dpi images – it’s all about viewing distance. On the web, images uploaded at 200 dpi are still displayed at 72 dpi – they just enlarge more. Attachments to emails can be any resolution, such as 72 dpi for viewing on the computer screen, or 200 dpi if the receiver needs to make a printed copy. Many companies have anti-virus software that rejects attachments. What if you have legitimate reasons for sending an image? Try placing it as an object in the text of the email. Magazines and brochures require images at up to 300 dpi to guarantee quality, though the final printed publication’s dot frequency is much less than this. The rationale – good quality in, equals best quality in print. A rule of thumb is to double the publication’s “screen ruling”, or printed lines per inch. Most Australian magazines (SILICON CHIP included) are printed at 133 lines per inch, so for best results require images to be 266 dpi. There is nothing wrong with supplying images above 266dpi (say Lighting for digital and lighting for film have the same fundamentals. Here’s a lighting tip: if only one light is available, try a mirror on the darker side. Carefully placed, a mirror can create desirable highlights and improved detail. One light. 34  Silicon Chip One light, mirrors and enhancement. siliconchip.com.au Another look at Photoshop’s “Save for Web” function: normally 60 quality is about right but as you can see, 19 quality results in a much smaller file size and one third the time to load on the web. It’s all a matter of judgement. . . 300dpi) but they will take up valuable storage real estate and will not achieve any extra quality in the printed job. What about artifacts? These are unwanted blocks of pixels or noise, caused through low resolution or highly compressed files. In most instances, for enlargements up to A4 (11” x 14”) from a 4 to 8 megapixel camera, you’ll never see artifacts in SHQ mode. You may see noise, or speckling, in dark/black sections of the print, especially if the original shot was taken in low light. Photoshop can also help out here! Image scaling Many digital cameras store their images 72 dpi, so, from what was said above, you might think that they will be unusable for printing in magazines or brochures. But if you have a look at the image size (it’s easy in Photoshop) you could find that the 72 dpi image might be 106 x 75 centimetres (over a metre wide!) – and an overall file size of 17.2MB. Converted to 266dpi and maintaining the 17.2MB file size (Photoshop again!), you have an image size of 28.7 x 19cm – almost A4 in size. Therefore you can use it at 266 dpi and 28.7 x 19cm with no loss of data nor emergence of artifacts; in fact, there will be no apparent change at all. It’s only when you start enlarging above that size (and maintaining 266dpi) that any interpolation (pixel manufacturing) – and therefore image quality reduction – will start to occur. Even then, you would be surprised what Photoshop lets you get away with! Cropping and enlarging Remember, too, that when talking about resolution we have been talking about the full captured image size. When you start cropping a picture, you start to throw away pixels. In exactly the same way as enlarging a tiny area of a film negative too far results in grainy or fuzzy print (ie, loss of clarity), too-tight cropping and enlargement of a digital image will cause problems. First you will see “jaggies” or jagged edges; with more enlargement you will see the image start to become fuzzy and it may be pixellated. One of the first lessons in Photography 101 is “fill the frame with the subject!” It’s far better to zoom into the siliconchip.com.au action when shooting, than try to crop to the action later! Lens focal length The effective lens focal lengths of digital cameras are less than 35mm, as nearly all digital cameras have a smaller image capture format area than 35mm cameras. With the Olympus E-300 or E-500, a 14mm lens is utilised to achieve the same angle of view as 28mm in film cameras. The spin-off benefits are: lower shutter speeds before camera shake blurs a photograph, plus greater depth of field (depth of focus). Other digital cameras, such as Nikons and Canons, have a 1.5:1 ratio – that is, a “55mm” lens (typically supplied with a 35mm film camera) will behave as if it is a 80mm lens and a 70-210mm zoom will act as if it is a 105-315mm – quite a “long range” zoom. Do your homework We’ve looked at a whole range of issues over the past two articles which we hope will help you with your digital photography. But before purchasing a digital camera, become very knowledgeable – do a lot of research, including on the web and in magazines. After all, a good digital camera is a major purchase. In fact, if you have a good 35mm camera and your local lab still processes film, there shouldn’t be a great rush to change. The longer you defer the changeover, the cheaper and better digital cameras will be. Already we have seen $2000 digital cameras replaced in just over two years by $450 equivalents. Further price reductions are likely to be less dramatic, as there is a limit to economy before significant quality loss. Most of all, when purchasing, don’t consider very cheap (sub – $300) cameras. Like 35mm cameras, cheap means inferior, sometimes very inferior. Digital has changed the world forever, improving new and old images. SC References and further reading: You’ll find a lot more information, tips and ideas on the author’s website: www.aaa1.biz/sc.html April 2006  35