If we wander into any art gallery which shows a variety of work we are likely to see pictures identified as “digital images”, but the term is problematic. An “image” is something we see, but in what ways can an image be “digital”? And what, really, is the artwork?
Analogue vs digital
Technically, digital is contrasted with analogue. Analogue changes in any quantity are continuous, i.e. smooth at every scale, while digital changes are discrete, stepwise. For instance, the minute hand of an analogue clock moves smoothly and its position can be read to any desired accuracy, while a digital clock will say the time is (e.g.) 8.22 p.m until it says 8.23 p.m.
Continue reading “Analogue : Digital”
The DSLR camera I have been using quite happily for five years was beginning to show its age before I visited Tasmania last November, miscommunicating with its lenses, failing to pop up its built-in flash on request, or under-exposing a series of shots, so I spent some time looking at replacements for it. That survey came to include most segments of the camera market, not just direct replacements, so I thought I might share its results here. I hope it will be useful but please bear in mind that it’s a personal perspective.
My needs are, as my title implies, off the beaten track. I want gear that I can carry easily enough while hiking and I want to take photos of birds (small and distant), bugs (smaller still but usually very close) and landscapes. People portraits? Rarely. Buildings? Sometimes. Continue reading “Cameras for rambling greenies”
Most of my photography is documentary, expressly intended to show its subject as clearly and literally as possible. Occasionally, as here, I’m tempted into altering a shot for expressive effect. I saw these trees on the Strahan beachfront early one evening, when the light was already fading to mistiness and ethereality…
For a more mundane view of Strahan, try my other blog, Green Path.
Several collections of European photos were posted to Green Path some years ago but they really belong here. I will move them as and when time permits but this index page will take you to them wherever they are.
For web use, pixels are all that matter. The image needs to be X pixels by Y pixels, and that’s all we really need to know.
The resolution (usually expressed in dots per inch, dpi) is not the same thing as the pixel size but says something important about how the image is displayed, on screen or on paper. For instance, an image 250 x 250 px may be displayed on screen at 96 or 120 dpi according to the device, making it (roughly) two and a half or two inches (i.e. 60 or 50mm) square respectively; or it may be printed at 300dpi, making it less than one inch (25mm) square.
File size (usually expressed in kilobytes or megabytes, KB or MB) is related to pixel size but again doesn’t matter much for display purposes. For a given pixel size, a larger file will appear as a better quality image but will take longer to load.