This week’s blog is about encouraging old dogs to learn new tricks

My father enjoyed photography. From the late 1940’s to the mid 1960’s he developed and printed his own black and white photographs. I have clear and fond memories of “helping” him in his darkroom (or “bathroom with the window blacked out” as other people might call it). The prints he produced were usually tiny by today’s standards. Often no more than about 5cm X 3cm. I think this was because photographic paper would have been an expensive luxury in the post-war years when his photography habits developed (ha-ha).

Receipt snapped by iPhone

Although it’s illegible here, this receipt is perfectly legible in its saved format for viewing on-screen or printing.

When I bought my own first camera (with money from my paper round) I also had to pay for my printing and developing costs. But I don’t think it would just have been schoolboys who found the hobby was still quite an expensive business in the mid to late 1960’s. As well as the cost, though, there was always the inevitable delay between taking a picture and seeing the results (even if you had your own darkroom).

All of this has changed enormously with the advent of digital photography and, especially, cameras built into mobile phones. I suspect that young people who have grown up with this technology automatically take photos of things that wouldn’t occur to older people, for whom photography was an expensive business that usually only happened on “special” occasions, and that required a bit of a rigmarole to produce visible results.

Whiteboard Shopping List

The photo is straight, the writing isn’t.

I may be wrong about this, but I think that older people may be more rigid in thinking about when it is appropriate and useful to take a picture. And I also think that the mental process that triggers the impulse to take a picture may often be started by the social situation. So, an older person would deliberately take a camera to a wedding or a christening and would expect to take pictures of happy couples and bonny babies. But would that same older person spontaneously think to take a picture with their smartphone of something that could be useful in the future but which may be more prosaic – a receipt for a taxi fare, for instance?

As you have probably gathered, I definitely include myself in the category of “older people” – as far as photography habits are concerned, anyway! I’ve been trying hard to create new habits of using the camera on my iPhone and I’m finding that, slowly, those habits are beginning to form. Here are some situations where it’s useful to remember you’ve got a camera – with no processing costs or hassle:

  • I’ve got a whiteboard in my kitchen and I jot down shopping items as they occur to me. Some brain cells must have jumped into action one day when I realised that I can simply photograph the list on the board before tripping off to Sainsbury (or Waitrose – we’re now getting posher in Clapham).
  • When shopping, I take pictures of items I’m shortlisting. This helps if I want to think about the choices later.
  • Also when shopping, I have taken pictures of labels with measurements (on storage items, for instance) to check later whether the item will fit.
  • On the underground, I take pictures of event posters (forthcoming exhibitions, for instance) so that I can remember to follow them up.
  • I have sporadically photographed items for insurance purposes (all of the toys I carry in my work bag, for instance, such as netbook, iPad, computer glasses, and so on). You can imagine other insurance situations – such as snapping the damage for which you are making a claim.

I’m also getting better at remembering business and computer applications – for instance:

  • Photographing licence numbers, usernames and passwords (yes, I know, these must be transcribed later and the photos deleted).
  • Taking a picture of the current wiring situation at the back of a computer so that I know what goes where before unplugging everything.
  • Just last week, a computer client snapped her computer screen and emailed the result to me because she wanted advice about what she could see on-screen. Great. Simple and effective. As I’ve mentioned before (see “Snipping and Snapping”), this is particularly useful if you’re seeing an error message that needs to be followed up and you want to record exactly what it looked like (and exactly what it said) before doing anything that could risk removing it from the screen.
  • Possibly the most useful occasion is to use a smartphone camera on all those occasions when you need to scan a piece of paper just to have a record on the computer, but when you don’t want to go through all the hassle of scanning. A smartphone camera may not give you the quality of a scan, but the result will be legible and will still provide that permanent record. I was discussing this with a client just yesterday. He already has a business-quality printer and was thinking that he needed a business-quality scanning solution to permanently store all the receipts he collects on his numerous global trips. His eyes lit up when I suggested trying the camera on his phone. He’s going to give it a whirl. If it works for him it will be a free and effective solution.

And then, of course, there are those spontaneous moments when you see something you just want to record and you remember you’ve got a camera with you! Here’s a couple I prepared earlier:

Billy Fury Way

Billy Fury Way – snapped in West Hampstead just last week. I know, I’m showing my age just by remembering him.

Excalibur arising from Long Pond, Clapham Common

Not a very good photograph, but it gives me a smile to remember the day I saw Excalibur arising from Long Pond,Clapham Common.

There are two main ways that a digital file can store information about an image:

Vector images are made up of independent objects (eg circles, arcs, squares). Each of these objects is defined in terms of mathematical relationships and instructions as to how to create it. A square, for example, is defined by where it is placed on the image, the length of a side in relation to the size of the entire image, the thickness and colour of the defining edges and so forth. This sounds complicated when explained in words but, in fact, the size of images made up of vector shapes is typically much smaller than an equivalent bitmap file (see below). This is because it is not the image itself that is stored – just the instructions necessary to re-create it.

Zombie - created as a vector graphicThe other main feature of a vector graphic (or image) is that it is “resolution-independent”. If you print a vector image the size of a postage stamp, its sharpness will be the same as if you printed it to fill a whole A4 page. Vector graphics are used in situations such as computer-aided design where images are made up of individually created elements and where sharpness and clarity at large sizes are important. Unfortunately, vector graphics won’t work for us in a lot of situations because the image (eg a photograph) can not easily be broken down into objects that can be defined geometrically and mathematically.

The image of the zombie was created as a vector image (source).

Bitmaps or raster images
are the more familiar format of graphics file for most people. In a bitmap file the image is composed of thousands or millions of individually coloured rectangles or dots, each of which is a single colour. These are called “pixels” (a contraction of “picture elements”). Pixels can be seen in the enlarged section of Tate Modern on the bitmap here.

Bimap image showing pixels

There may be a choice of up to 16,777,216 colours available for each pixel. So, if you imagine a grid of 3000 pixels in one direction and 2000 pixels in the other, in which each pixel could be one of 16,777,216 colours, you are imagining what a bitmap image looks like. In this case, there would be 6 million pixels (3000 X 2000), so this is would be a “6 mega-pixel” image.

The problem with bitmap images is that they can be large – very very large – in terms of the space they take to store. It takes an awful lot of zeroes and ones to define 6,000,000 pixels when each pixel can be one of 16 million colours.

So, we can now say that the smaller, resolution-independent, type of image (ie the vector graphic) isn’t going to be any good to us if our images are, in fact, photographs (or anything else that can not be broken down into individual geometric “objects”). Therefore, we are usually going to be using bitmap (raster) images. This means that we are going to have to struggle with the play-off between the size of file that we create and the quality of the final image. It is largely to achieve the best compromise in this play-off that there exist several types of bitmap image:

Tif (or tiff) files tend to produce very large files because all of the information in each pixel is always retained (this is known as a “lossless” image type). This has advantages for quality but disadvantages for file size. It is often the preferred file format for people creating and editing images (including photographs) using photo editing software such as Photoshop.

Gif and png files (pronounced “gif” or “jif” and “pee en gee” respectively) are graphics formats producing very small files. They are mainly used for images on web pages. The small file size is achieved by reducing the number of different colours in the image to the minimum necessary to create that image at an acceptable quality.

Jpg or jpeg files (pronounced “jay peg”) are the most favoured for finished photographs. Almost all digital cameras will create jpg files (although a lot will also create other formats). The advantage is that the file is compressed to be smaller. The price to be paid for this is that some loss of information (which translates into picture quality) will occur. This probably won’t be too serious to begin with, but if you repeatedly edit and save a jpg image then the quality will continue to degrade.

Raw is a “lossless” format produced by many digital cameras. However, there are lots of flavors of raw images so you may need the software provided with the camera to handle them.

Bmp (bitmap) is a Windows specification of a lossless file. Bmp files can be large but they have the advantage that they can be handled by almost all programs that need to deal with image files . And, yes, we do now have two different uses of the word “bitmap”. It is used synonymously with “raster” (as distinct from vector images) and is also used as the name of a specific Windows file format.

Apart from the image itself, most image files can also carry other information (called “exif” information or “metadata”) that can be used and displayed by image-handling programs. This can include, for example, the camera type, exposure information, date and time of exposure, and – somewhat controversially – the exact geographical location where the photograph was taken (known as “geotagging“).

Although I’ve tried to keep this simple, we’ve only scratched the surface (ha-ha) of digital photography by just looking at how digital images are composed and the main formats of files. Next time, I will look in more detail at jpgs as these are initially the most commonly encountered files in digital photography.

© 2011-2019 David Leonard
Computer Support in London
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