articles/Digital/slayerofdragons-page2
Published 01/02/2005
Myth 4:
There is little or no difference between sharpening an image in the camera or after capture in Photoshop.
Wrong! Sharpening performed in the camera or applied to the RGB channels after can alter the colour of literally millions of the pixels. The example seen here compares the eye in a portrait and shows the difference between RGB/Lab sharpening methods. Like colour andtone gamuts sharpness is dependant on the setting and resolving power of the output device. In addition sharpness varies with image size - one sharpness setting may not suit all output sizes and resolution. For speed, where optimum image quality is not essential, and output prints are less than 10x8 inches, the sharpness could be applied in the camera.
This 'quick & dirty' approach works - most of the time. However, if the image has to be lightened then there is a good chance of increasing the amount of noise, particularly in the blue channel. If the image is not sharpened until Photoshop it is possible to obtain cleaner (and greater) sharpness without noise, by converting the image to Lab mode and using the Lightness channel.
Myth 5:
Digital cameras don't have the same exposure latitude as colour neg film.
They do, but in a different range of the tonal spectrum. Instead of being, say, plus/minus one stop it's all in the minus range. Contrary to what many may believe, more than one stop overexposure of a colour neg will lose highlight detail or, if printed to show highlight detail, midtone and shadow detail will be lost. The only way to get the full tonal range from such a neg would be skilful hand printing - and you know how much that costs, if you can find a lab that does it nowadays! Yes, digital capture is intolerant of overexposure, but it is far, far more forgiving of underexposure. Most of the problems I come across regarding exposure are because photographers expect to pick up a digital camera and use it as they would a (neg) film camera. Those used to working with trannie film have had less problems as they already have the disciplines necessary. Having said this, digital capture allows far greater image adjustment than trannie film, with the added advantage the exposure can be checked immediately after capture. Colour film has a fixed gamma whereas with a digital camera it can be altered. This means (roughly) that the tonal capture range can be varied to suit the subject range. The ability to do this with a digital camera is not well known by photographers, and I think it is one of its most useful benefits. Just how far the gamma range can be extended depends upon the points mentioned earlier. Through my workshops I get to see and test every pro digital SLR there is. The sequence of image tests I run push the cameras to their limits and reveal the best and worst. Price has no bearing on performance, in fact, some of the most expensive cameras produce the worst results in all but ideal shooting conditions!
Myth 6:
Using fill-flash with digital cameras is more likely to give overexposed images.
This can be completely eliminated if a number of simple rules are followed. First, choose a camera which is known to have an accurate flash sensor system. Of all the digital cameras I have seen and used at our workshop shootouts, Nikon and Fuji cameras are the best for consistent accuracy under all shooting conditions. By far the worst is Canon, with its ETTL system - it has frustrated Canon users for years. Several dedicated Canon users have come up with their own workarounds but none are straightforward. Nikon, on the other hand, have a superb TTL flash metering system, which is also incorporated in the Fuji S2.They (Nikon) have even improved on this with D-TTL, which is in their latest cameras, and the new Fuji S3.
However, no matter what camera is used, I have found, from many examples I have seen, that the main problem with overexposed flash pictures, is not caused by the flash! Look at the two pictures of the bridesmaid shown here; the one on the left appears to be over flashed, but in reality it is too much ambient light, caused by the camera metering being fooled by the darker-than-average background. Camera metering systems read most 'foliage' backgrounds as dark and overcompensates. The solution is simply to dial in minus one or more stops and the balance is perfect. Much of the criticism of the performance or capabilities of digital imaging has come from those who have dabbled or apply 'analogue thinking' and find the results - compared to film - less than what they expected. The transition to digital has not always been smooth, particularly when buying cameras, as many have relied on the 'badge name' as a guide to performance. Others have stuck to the same name because they have an expensive array of lenses, and changing to anotherbrand of camera would mean starting again.
Let's just stop for a moment and consider these facts: I still have a 30 year-old Nikon FM2, with some of the best lenses available at the time. Although somewhat battered, it takes better pictures now than when I bought it. Why? Because of the advances in film technology over the years. The same would be true of any top-notch film camera. But what about digital cameras? The opposite is true; from the moment is comes out of the box its performance remains the same (barring optics), apart from some minor firmware upgrades that may be available.
If ever there was a time to 'road test' before buying, it's when choosing a digital camera. The vital elements that create a good image can't be seen or perceived from brochures etc. Not all pro digital cameras are the same - some perform well in the studio but on location, under variable lighting conditions, are simply hopeless. For now, and the foreseeable future, digital SLR bodies should be seen as 'disposable cameras' to be replaced as advances in technology provide practical (not superficial) improvements in image quality. This means, from a business point of view, digital cameras should be treated as a consumable rather than an accounting asset. Considering the falling price of each new digital body, the cost, if amortised over 18 months would be less than £90 per month to keep up with each new major advance in digital camera technology.
Success in photography requires a mix of creative and technical skills, and one should never dominate the other. Digital imaging does require mastering and applying certain disciplines. Learn them, apply them and they will allow your creative side to reach new heights.
By the way, I have just field-tested the new Fuji S3 camera - if you want to see the results, including some 30-inch prints, come along to the Fuji stand at Focus on Imaging at the end of February - hope to see you there.
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