Programming references?

I must have been fortunate in that my higher education took place about the same time as the personal computer was starting to make an impact on everyday life and the world was starting to turn digital. It was a good time to be in computing -- despite what my parents thought, especially my father (bless him). Over the years I have been able to make a modest but comfortable living from IT, and so it continues.

When I started out I wanted to be a programmer, and my wish was fulfilled immediately after I had finished university. Even though I then moved into (computer) Systems Administration, I have always enjoyed programming and try to keep my hand in, even if it is only simple shell scripts which are then subsequently discarded.

Pre-university, probably like thousands of other people, I taught myself BASIC, no doubt with some common bad habits. In university, I was taught -- or was expected to learn at various times -- FORTRAN, Pascal, PL/1, SNOBOL, PDP Assembly language, and C. I subsequently picked up Intel 8086/8088 assembly language , Bourne shell scripting, and Perl. (Some of the programming reference books I used can be seen in the photo.) I briefly dabbled with C++ and PHP, but Java and JavaScript completely passed me by. Either shell scripting or Perl are my weapons of choice for repeatable systems administration tasks and projects.

In recent years, I have heard much about the scripting language Python. It is the favoured language for a number of my users, and the Debian Linux packaging system is written in it. I have received a number of requests to install new Python packages, or update existing ones. (This does not require much Python knowledge, fortunately.) Perhaps it was time that I learnt more about Python?

With this in mind, I sought a suitable reference book -- as I have found a portable, printed, read-nearly-anywhere guide had been essential in the past. I have long been a fan of the O'Reilly series of books, so this seemed like the obvious place to look. My copy of Programming Perl had served me well over the years; I wanted an equivalent written for Python. So, rather than check the wisdom of the internet and look more closely at what I was asking for, I put O'Reilly's Programming Python on my Christmas gift list...

My sister was kind enough to get it for me. What arrived was this monster volume of 1600+ pages that can be used to prop doors open. It is not such a pleasant experience to carry it any distance, and its size makes it difficult to easily keep the book open on certain pages. Had I done just a little more research, I would have noticed that it is big by the page count: 1632. And also that it should have been named more appropriately as Using Python. (Perhaps I should have been looking at Learning Python instead, all 1648 pages of it?...)

To use a bit of (Monty) Python: Stop, this is silly! The general consensus is that it is easier to learn Python than it is C, so why does it take 1600 pages to cover what the seminal The C Programming Language seems to do in 200? (I know this is being provocative, as the C book assumes a single version of the language, a Unix OS, a command line and a limited number of libraries. Things have moved on since the 1990s.)

In praise of the tea light

It would have been the mid-1970s when I first came across the small candle known as a tea light. My parents had bought a filter coffee making set from the Ideal Home Exhibition, and shortly afterwards a metal warming stand was purchased to help keep the coffee warm. Heating was provided by a single tea light. It did the job -- but I suspect that tea lights weren't as readily available or as reasonably priced then as they are today -- so use was for special occasions only! I remember being intrigued by the way that the wax completely liquified and was contained by the foil cup, as well as how the wick was anchored to the bottom of the cup.

Many years later I wanted a source of room candle light, and all the local supermarket had available was a pack of tea lights. Not the box of household candles that I might have found three decades earlier. All right, I needed to use two tea lights where I would have used a single candle, but it was fine. (Household candles are still available if you know where to get them -- yes, I remember the UK power cuts of the 1970s and the shortage of candles...) In general tea lights are easier to use, safer and cleaner. And of course they are now more widely available, including scented varieties if that's your thing.

The classic tea light has a cup made out of thin aluminium containing unscented white wax -- which becomes transparent when molten. The cup is normally around one and a half inches in diameter (37 millimetres). The wick is fixed to the bottom of the cup using a metal (steel?) "tag ": a collar gripping the wick attached to a circular base. This should burn continuously for at least four hours, and then self-extinguish when the pool of melted wax runs out. The empty cup can then be (safely) disposed of, or even recycled?

My internet searches have not yet come up with who first developed the tea light as we know it today, and when. I suspect it might have been as far back as the 1960s and in the U.S., but I would be delighted to be corrected. (The diameter suggests that it would be somewhere using Imperial measurement units?)

As well as the original design, tea lights are also available in longer-burning versions (sometimes referred to as night lights), and in larger diameters. Another variation is the replacement of the standard foil cup with a transparent hard plastic version, which is especially useful when the tea light is used for illumination. (These appear to be harder to find in shops, and more expensive.)

Tea lights have come into their own as dining table candles when placed in decorative tea light holders -- mostly made from glass or transparent material. They have especially become a common feature of restaurants and at wedding receptions in the UK. A holder fulfills at least two functions. It helps protect the tea light from being accidentally knocked over or touched, and it (usually) enhances the light from the flame. There are now dozens of different designs of tea light holder available, so there should be something to suit everyone.

A tea light in a good holder can be lit and enjoyed for as little as half an hour without showing signs of candle funnelling -- so it is ideal if you don't have the time to do a larger diameter candle justice. If you find the light of a single tea light to be a bit feeble, two or more can be clustered together to compensate for the smaller flames. Candles in general are now considered to be luxury items (with some prices to match), but the wide availability and reasonable price of tea lights -- especially when bought in bulk -- means that you don't need to pay luxury prices to enjoy them!

Candles from IKEA

I was recently visiting my "local" branch of IKEA intending to buy a small bookcase, when the idea suddenly popped into my head that I would like a candle in a glass container. I'm not sure where that one came from, as I rarely burn candles apart from the occasional Price's Chef's Candle to reduce strong cooking smells. IKEA certainly has plenty of candles, including a number in glass containers, so I had come to the right place. Needless to say, given the attractive prices, I left with more than just a candle in a glass. (And a bookcase.)

From my earliest memories, candles had been a component of special celebrations -- normally birthdays and Christmas. They were expected on top of birthday cakes and featured prominently during the season of Advent in the excitement of the lead up to Christmas. The warm, soft light and flickering flame held a fascination for me, verging on the transfixing. Part of the wonder of my childhood.

In teenage years, experiments with home-made candles and miniature hot air balloons caused at least one significant wax spillage on the bedroom carpet -- thankfully without fire! Having had at least one close call, I assume I must have learnt my lesson and candles then became something to be enjoyed only at Christmas (and avoided at birthdays) on visits home. (I am happy to watch manned hot air balloons float above me in fine weather, but untethered Chinese Lanterns drifting above the local countryside fill me with concern!)

IKEA prices seemed so reasonable, that it was easy to add more items to the shopping  bag. Apart from the lime-fragrance SOMMAR 2018 candle in glass, I came away with a number of unscented pillar candles (not all shown), and three different packs of tea lights. I could not resist the quirky, stackable chunky glass tea light holder, and grabbed a number of them. (At 37p each, how could I not? They really make a difference with standard tea lights.) It should take me a while to get through this lot!

Most of the candles shown here are made for IKEA in Poland, and all the ones I have tried so far have been good or excellent, and definitely good value for money. (I wouldn't have expected otherwise.) The product labelling shows a number of safety-related pictograms (e.g., Do not leave a burning candle unattended), so it is worth working out what they all mean -- a set of sensible guidelines before lighting. One of them suggests that the wick should be no longer than 1 centimetre (10 mm), but in practice a trim to 4 millimetres before lighting has given me reliable results. (I use a slice of plastic drinking straw as a collar over the wick when trimming with nail clippers to get fairly consistent wick lengths.)

The labelling also shows a burn time in hours, e.g., 4h for a standard GLIMMA unscented tea light. I suspect this is a minimum for continuous burning with a stable flame. I have achieved longer candle life by using shorter burn times, followed by wick trimming before the next session. I suspect that with proper candle care (regular wick trimming and a melt pool covering the entire surface of the candle before extinguishing), it should be possible to extend IKEA's advertised burn times by 20 percent or more.

I have never been a fan of scented candles, and most of IKEA's offerings are sweet-smelling and/or fruity which is not my thing. However, in tea light form I have not found them to be too offensive. (I understand that the size [diameter] of the melt pool influences the strength ["throw"] of the scent.) I am aware that scented candles from other sources can cost big money and are truly luxury items. A case of getting what you pay for, I suppose?

Ironically, what set me down this path has been the least satisfactory. Despite trying a number of different wick lengths and burn times, I was unable to get my SOMMAR 2018 lime-scented candle in glass to form a melt pool all the way across, and it has exhibited classic funnelling. Either the container is too big or the wick too small -- a design or manufacturing fault? (I reject the idea that candles have "memory" -- utter nonsense and a feeble excuse!) Additionally, the lime scent took on a different character once heated by the candle, and lost its freshness; to be replaced by a more sickly, creamy fragrance less to my liking. I don't think I will be buying another one of these, but I might just try a peach SINNLIG in the small glass on my next visit to IKEA...

Watercolour reference cards

Perhaps this is something that comes with experience, but when starting out with watercolours, something that made the learning curve a little steeper for me was the difficulty in being able to correctly identify dried paint colours in their pans. Dark colours especially can look very similar when dry. Winsor and Newton now print colour names and pigment information on their exterior of their pans -- which helps somewhat -- but even then, this does not show when the pans are in position in the palette.

One approach might be to arrange the pan colours in specific locations in the palette, so that with regular practice it becomes instinctive as to where a particular paint is located. However, this scheme discourages the use of new and alternate colours in the course of skill development and experimentation.

My solution has been to produce "watercolour reference cards" to fit inside the paint box. This serves a couple of purposes. Firstly, the card clearly shows the position of each pan colour in relation to the others. Secondly, it acts as a (small) colour swatch, permitting decisions to be made on whether the paint is a good starting point for a desired colour.

I use a small pad of Cotman 90 lb Not paper to make my reference cards. I measure a strip to fit inside the Cotman Sketcher's Pocket Box, and then use a stencil cut from a strip of clear plastic (long sleeve shirt collar packing) to draw a number of square swatch boxes in HB pencil. (This saves the trouble of measuring and marking out the squares individually -- see the photo.) I then label each box with the paint it will contain, and then paint the swatch in each.  When all the swatches are done, I cut out the strip to make the reference card and place it inside the paint box.

Even with 90 lb paper, I have found that it is possible to paint swatches on both sides of the paper. So if you are organised enough to have a couple of combinations of  preferred pans, it might be only a matter of flipping over the reference card to ring the changes!

Caesar's Gate

The box art of a surprising childhood survivor! Despite some six moves of home in the space of 20 years, this Airfix playset was somehow spared the culling and disposal that unused and/or unwanted possessions inevitably suffered in the process. I'm sure I must've spent hours assembling and marshalling the figures contained within once upon a time, but that is now too long ago to remember clearly. The box probably hadn't been opened since the mid-1970s.

The dramatic picture shows what seems to be a small skirmish between Ancient Britons and Roman soldiers -- about to be reinforced by a larger force of Romans sallying forth from a fortlet (milecastle on Hadrian's Wall?). Presumably, we cannot see the main body of the Ancient Britons? All designed to stir the imagination! (It obviously worked for me.)

If you look carefully, you can see that the original price is written in pencil either side of CAESAR'S GATE: both 13/6 (thirteen shillings and sixpence) and 67 1/2 p! Given that decimalisation of the UK's currency didn't take place till February 1971, then this box must date from before that.

Remarkably, the contents appear to be complete and undamaged. Even the original instructions are still present, hiding under the snap-together buildings. (I was brought up to take care of my things.) The outer lid shows the expected signs of use and wear, and also some staining at the top where it must have got damp or wet. (Oh dear, I don't know what happened there!)

I have been interested in the Romans for many years -- I still am -- and even at the tender age of ten or so, I knew that the fortlet was a fairly good representation of a Hadrian's Wall milecastle (albeit that the defensive walls would be thicker and the precise ashlar masonry construction would be considerably rougher on the real thing).

My reluctance to part with my old possessions has apparently made this a collector's item now. A quick scan of the internet suggests that it might be worth around £60 (at early 2018 prices) -- although I have also seen examples listed for €150! I would be happy to see it go to a good home if someone would like to make me a suitable offer...

Camera testing

My camera of choice is still the compact Canon Powershot S95, as it is capable of taking some delightful photos in challenging conditions: its small size means it is comfortable to carry around and does not draw attention to itself unlike bigger ``enthusiast'' cameras.

The digital camera market continues to evolve, and the technology enables things that were not possible when film was king. (Usable photos hand-held in near darkness!?) One development that caught my eye is the Micro Four Thirds system -- cameras with the controls and features of DSLRs, as well as a range of interchangeable lenses -- but without the same bulk. The all-important sensor is 30 percent smaller than Canon's APS-C sensor (as used on consumer DSLRs), although this is not as bad as it seems because the aspect ratio is 3:4 rather than the wider 2:3 of the DSLR. So when I became aware of what seemed like a good deal on an Olympus PEN E-PL1 camera package at Jessops in the autumn of 2012, I was curious and unable to resist.

The kit came with the camera and two lenses. The camera has few external manual controls and is clearly aimed at the compact camera user looking to upgrade. However, once you get into the menus, there are a bewildering number of options and things that can be adjusted -- on par with consumer DSLRs. The supplied lenses included the standard wide angle to short telephoto (14-42 mm) zoom for everyday use, and a longer telephoto (40-150 mm) zoom for additional distance. Both lenses produce very acceptable results.

Some five years later, I find that I have taken fewer than 500 photos with my E-PL1 (and around 50 of those were test shots), while my S95 has notched up nearly eight times as many in a similar period of time. Despite the bigger sensor on the Olympus, why would this be? I suspect that it is a combination of the basic point-and-shoot nature of the E-PL1, and the default colour of the E-PL1 -- which I initially found a little overpowering!

Nevertheless, I think I may have finally tamed the colour on the Olympus camera. The image above is the result of a number of incremental adjustments over a couple of years to picture mode, saturation, contrast, and auto white balance correction. Having mounted the long telephoto zoom lens, I set the shutter speed to 1/500 second, aimed the camera and pressed the shutter release button. This is the result -- the first time I have used this lens on a moving subject. (An HST at speed heading west on the former GWR mainline near Denchworth Bridge, on a glorious winter day on 28th December 2017. I understand that the OHLE is not yet live: it looks as though the contact wires need to be tensioned, but this may be an optical illusion?)

I think I need to take the Olympus PEN E-PL1 out with me more often!...

Para's Progress 2

If it is not already obvious, then it should be apparent from these photographs that I am not an expert miniature figure painter! The hobby of miniature figure painting is an absorbing pastime in its own right, and there are a variety of resources available on the internet to provide inspiration and instruction. (Not to mention a number of excellent publications in print.) This however, is another update on my quest to paint an original Airfix 1/32 scale military figure.

Our journeyed figure starts this installment adorned with a grisaille of dry-brushed grey and white over a base coat of black. The next stage is to apply layers of thinned paint that are translucent enough not to cover up the shadow and highlight details. (Some people refer to this technique as Stain Painting; it is essentially the same process as was used to colour Victorian and Edwardian picture postcards.)

Coloured paint will start to bring life to the monochrome figure. General wisdom suggests that it is best to start with the inner layer -- often skin -- and work outwards. So the face and hands were the first things to tackle. I like to start with a pale pink layer (White and Red Ochre), and then glaze that with a pale orange-brown layer (White and Burnt Sienna), possibly finishing off with a glaze of pale milk coffee brown (White and Burnt Umber) to suggest time spent outside.

Using artists' tube paints, I take a small blob of white on the mixing palette and thin it as I see fit with my glazing medium (Galeria matt medium diluted 1:8 by volume with water). To this I add a minute amount of colour to tint it, mixed well, along with a little more glazing medium. I apply the paint sparingly, with a Pro Arte Acrylix size 2 round brush, preferring to wipe it over the surface with the sides of the bristles rather than the tips. If necessary, I will touch the brush to a piece of facial tissue first to ensure that it is not overloaded with paint.

That is the theory anyway. As you can see, I was guilty of (a) using Mixing White (transparent) rather than Titanium White (opaque), and (b) having the brush loaded with too much paint so that it flooded shadow detail and flowed where it was not wanted -- such as on the rifle and between the fingers. The transparent white resulted in poor coverage of the face and hands: I redid the Burnt Sienna and Burnt Umber glazes using Titanium White once I had realised my mistake, but it is lacking the pale pink glaze. I am hoping that darker colours will sort out the unwanted white on the rifle later...

A simple method to test the covering power of the paint, is to use a piece of unwanted printed paper (black type on a white background), and brush over a word of print with the mix first. If the outline of letters can barely be seen, then the mix is too thick and needs to be thinned. Conversely, if the letters are still distinct after a layer of paint, then the mix is too thin and needs more paint. It should be possible to get a paint mix to cover adequately with one application, but achieving the right consistency is easier said than done. It is better to err on the side of too thin and apply at least two layers for even coverage.

The figure's lips were carefully painted with a glaze of dark purplish-pink (Titanium White, Red Ochre and a touch of Ultramarine) using a size 0 Acrylix round brush. I ducked out of doing anything fiddly with the eyes as they are just below the line of the helmet, and are mostly in shadow anyway... A couple of glazes of Burnt Umber with a dash of Titanium White helped suggest brown hair below the back of the helmet.

The battledress trousers are supposed to be British Army WW2 khaki, which is actually a woven blend of green and brown threads, and explains why sometimes it looks green, and sometimes brown. I struggled to mix a satisfactory colour, and tried four different thin layers, applied with an Acrylix size 4 round brush. The last glaze was a slightly thicker mix of Galeria Olive Green and Liquitex Raw Umber, which seemed closest to what I had in mind. But of course the earlier layers will influence it too. I am not going to lose sleep if the colour is not spot-on: it is the impression that I am after.

Things will only get more complicated from here on, as a later installment will reveal...