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Close Encounters

I like cameras with high zoom ratios, not for telescopic photos, but for taking pictures of small objects at close range - you can put your camera close to the object, but this tends to distort the scene because of difference in distances to different parts, e.g., if you shoot a face too close, the nose tends to be big and ears small; moving away and zooming in solves this problem but creates another: by receiving light from a small object from far away, the picture tends to be too dark; using the flash may not be enough because only a small amount of light reaches the object from the camera if it is far; you often need to add lighting: 

more details are captured but the flash reflection is a bit annoying.

Now a carved seal shot at 2' with 10x zoom, reduced 50%

then unreduced detail

a satellite dish on top of the old NUS School of Computing 3rd building shot from about 0.5km away at 10x zoom

the back of the dish from much closer up, also at 10x zoom

finally a photo of the canopy over Clark Quay, taken with Lumix LX2 wide angle, reduced to 20% yet with excellent details - it shows that even an inexpensive camera these days has more pixels than most users need

A section was cut from it, now without reducing, but with some brightness/contrast enhancement as it is somewhat dark:

with excellent detail though zooming was not used in taking the photo; with 4x zoom the result is

 now 10x zoom (using Kodak instead of lumix)  

now about 18x zoom, using a telephoto extension lens, which unfortunately seem more likely to hinder than help in getting additional details:

at high zoom a small camera movement shifts the scene a lot, and it must be held very steady, but even on a tripod the camera tends to swing back and forth because the metal legs flex; however, this scene is quite brightly lit by the daylight sky and exposure time is still quite short despite the high zoom, hence a slow swinging movement did no serious damage.

Choosing a digital camera

I am not an early adoptor of new technology; I always wait for the price to drop to bargain levels, by which time the products I buy are nearly outdated and about to be superseded by new things (so another wait for price to drop). So maybe you would prefer to read someone else to know about the latest exciting things. On the other hand, my comments might be more usable for the average person, since most of the technical reviews are over my head and most probably over other people's as well.

1. Pixel count: These days even the cheap cameras have 5M pixels, and moderately priced ones have 7 or 10M. While more is obviously better for the purpose of capturing details of the scene you shoot, the question is wether you want to pay for this. In my view, 7M or more only make sense if you have wide angle lens on the camera - more details only if you have a larger scene. A larger pixel count also means a larger CCD screen to receive light and turn it into electric charges which are then measured to produce a matrix representing the picture colour values, as well as a larger LCD screen at the back to show you the picture being taken.

2. Aperture size: A larger aperture means more light is received into the camera to activate the CCD screen. However, camera specs do not usually tell you the physical aperture size, but a ratio (f/xx)) of aperture size to focal length, with smaller xx indicating larger aperture, but you can see the size just by looking at the lens itself, especially if there is a rectagular entrance behind the glass which shows you exactly the size of the light receiving opening. (Focal length determines the angles of light allowed to reach the CCD screen, and a larger f means a smaller angle and less light.) A small aperture size in combination with a large pixel count means each pixel receives a small amount of light, and getting sufficient light for a good image exposure may require either the use of the flash or a long exposure time. The former may make the colours less natural, and does not work on distant scenes, while the latter increases the chance a fuzzy picture due to camera shake. Some cameras try to electronically invert the camera movement but the result may still be inferior.

3. Zoom ratio: Now most cheap cameras have a 3x zoom, and 10x zoom is not uncommon among moderately priced ones. Camera specs normally express the zoom ratio in lens focal length terms, e.g., 35-105mm is a "standard" 3x zoom, with widest image when the lens focal length is set at 35mm and narrowest image at focal 105mm; 28-280 standard 10x zoom with 28mm focal length receiving image 25% wider than 35mm and 280mm 2.7 times narrower than 105. A high zoom focuses on a small part of the scene, and light from this is spread over all the pixels so each pixel only receives a little light, e.g., at 10x zoom light is received only from 1/100 of the 1x scene; hence, a high zoom ratio would only work with a large aperture size. A high zoom also requires a long lens assembly, but as most cameras try to reduce their sizes adopting a retracting lens assembly made up of several sections one inside another, the inner tube only has a small opening for the lens entrance. This combination of large zoom ratio with small aperture ratio exacerbates the low light problem. In otherwords, a large zoom ratio goes with a bulky camera. Some cameras (lik my Kodak) can take telephoto or wide angle extension lenses that extend the zoom ratio at the high or low end though the result wont have the sharpness provided by SLR zoom lenses of the same ratio.

4. SLR: "Single lens reflector camera" originally had a specific meaning relating to the construction of the viewing eye, which shares the image received by the film through a mirror, but with digital cameras the phrase actually means something else that came with that construction: cameras with multiple lens assemblies that could be removed to change to another one. In particular this allows the same camera body to be used with lenses of various zoom ratios, thus going beyond the zoom ratios available with a single lens. Unless you are a real expert photographer, I would not recommend SLRs - prices have come down a lot but fiddling with different lenses is just too troublesome; some moderately priced cameras already have 18x zoom, more than enough for most people.

5. Memory cards: Here you need to know whether the camera stores images in bmp (bitmap) or jpg (joint picture group - which defined a compression standard); each pixel has 3 colours with 256 intensity levels so 10M pixels mean 30M bytes per picture; after compression the byte count might be only 2M; hence, a 1 or 2GB memory card can hold many jpg images but only a small number of bmp images.

I have a Lumix LX2, with a small body but large looking lens, and 10M pixels with wide angle, 4x zoom:

I also have a Kodax Z740, with an even larger lens, 10x zoom but only 5M pixels, bulky, but cheap. It seems I must have been following my own advice in choose cameras, but alas, not so...

I bought my first digital camera, a Canon Ixus, in 2002 at Comex; before this I had been looking around and thought the specs of this model, and a similar but slightly smaller Pentax, "good enough" - 3x zoom (at that time the maximum among the small cameras), 3M pixels, etc. My interest was strengthened by my son's reaction when we were looking together - being from a more comfortable generation than mine, he basically dismissed most cheap cameras as junk but found those two acceptable. So when the Comex Canon booth advertised that the list price had just been cut by $100, and they were also giving 2 free memory cards (quite expensive in those days), I went and bought one. Until then I had never touched a digital camera - window shopping only.

A year or so later I gave the Canon to my son so I was on the lookout for a replacement, and saw an Olympus with similar specs going for half the price - by then everything had come down but this one was cheaper still, so I bought it. After taking it home, I understood why it was so cheap - it used AA batteries and did not require a charger, and because of the power surge needed to use camera, particularly the flash, you have to use expensive lithium batteries. Not using it often, I guess I did not end up paying back the price difference on batteries.

I have since given the Olympus to my daughter. Now I have two new cameras; the Kodak Z740, which uses AA batteries, was only half the price of the Lumix LX2, and had high zoom but low pixels, and no wide angle/panorama shots. Perhaps the Lumix TZ, with 10x zoom and 7M pixels, could have done the job of both, though with a light intensity problem, and it produces panoramic scenes by cutting down from 7M to 5M, while LX does it by increasing from 7M to 10M, but that was not why I chose LX - the reason was LX was sold here at the same price sold in USA, while the TZ is US$100 cheaper over there but sold at the same price as LX here. So LX looked to be a better bargain.

You see I do not follow my own advice, but that need not stop others from doing so

(This was written in 1997, shortly after the IBM Deep Blue defeated Gary Kasparov in a 6-game match)

Deep Blue, AI and Chess

Since Deep Blue's historical win over Kasparov, commentators have tended o play down the significance of the event. Computing people usually say that Deep Blue's chess analysis is by brute force, considering every possible move, instead of the human method of intuitively eliminating most of these moves as unsuitable and concentrating on the more relevant possibilities, while chess people say that Kasparov used the wrong anti machine strategy and played below par, and that Deep Blue's capabilities have not been tested against a variety of opponents. All that is true, but the fact remains that Deep Blue played extremely powerful chess, and will be even stronger next year. It might not yet be guaranteed to beat any human player, but would certainly reach that stage in the near future.

From those chess lovers who feel the Deep Blue win would provide good PR for the game and make its future brighter, I must beg to differ: a decline in the status of chess is difficult to avoid now that the machine "had it all figured out". It is true that humans continue to have Olympic games even though machines can run faster, jump higher, etc., but the analogy is not really applicable: there have always been animals that run faster and jump higher than humans, and so to have machines doing the same was no great blow to the human ego. The human's ability to do certain things that animals could not do was an indicator of its superiority, with
even some religious significance. Now that a machine can go it better, the very "human" response of the humans will have to be "oh it is not a big deal; it is only a game, like scrabble or monopoly".

In fact, why is chess more highbrow than scrabble and monopoly? It is more historical and more international because it involves purer logical
reasoning, independent of the language and cultural backgrounds of the players. It attracts a more intellectual type of follower, who could probably have good careers as mathematicians, accountants or architects, but choose instead to devote their lives to playing, analysing and writing books about chess. But if no matter how hard they try, they will never be as good as a machine, it is hard to imagine that such people would continue to select chess as their career; again the situation is different from running and jumping, because sportsmen like Donovan Bailey do not really have the same career choices.

It is correct to say that Deep Blue is not intelligent in the way a human is, and it does not learn in the way a human learns. Machines will continue to solve problems in their own laborious and clumsy way, but its way is not necessarily inferior. Humans summarize their memories and experiences in some unknown ways, and use these to make intuitive, often unexplainable, decisions that seem to be "right", and to seize upon the important aspects of a problem. Machines cannot do this, but it can remember great amounts of details accurately, and with the right program, use the details effectively.

For example, the performance of chess programs took a significant leap a few years ago when programmers put in code to guess what moves an opponent might make and search for the best answer for each possibility, while the opponent is thinking; when the opponent actually makes one of these moves, the machine can respond very quickly, thus reducing the use of its own play time. This occurred frequently during the recent match, with Deep Blue consistently putting Kasparov under time pressure. A human player cannot do the same, because he would not be able to remember all the possibilities clearly; even if he might have guessed and analysed an opponent's possible moves already, he would still have to spend time thinking after the opponent actually makes a move.

On learning, the machine has the great advantage that it does not forget and can add to its stored knowledge constantly. Further, it can easily transfer its knowledge to another, bigger and better, machine whereas the next world champion after Kasparov has to learn chess from scratch; no matter how hard he studies the old games of Kasparov and takes lessons from him, the new champion cannot be sure that he has acquired all the experience that Kasparov has stored in the head. Thus, in some ways, machine learning is more effective than human learning.

Some commentators have mocked the machine's lack of creativity. In fact, it is easy to add creativity, though that too would involved the clumsy and laborious machine way: you randomly generate all the possiblities, and use predefined facts and rules to eliminate unsuitable ones, producing the better possibilities. Like Kasparov said after the first game in last year's match, the machine uses quantity to produce quality, and this year's result shows only too clearly that greater quanity can indeed lead to better quality.

The victory of Deep Blue may be no breakthrough in computing, AI or chess, but it is all the same a very significant event. I strongly advise humans against complacency.

Added in 2000: Gary Kasparov lost his (human) champianship match in November 2000. In fact he had been playing under par ever since the match with Deep Blue, which shows another machine advantage: it does not get tired or demoralized.

Added in 2007: So far the new human champions have not done well against the computers, and I dont see the situation reversing.

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You may wonder why I was talking about chess here. Well, after some experience with simple, and inexpensive cameras, I began to feel that photography is going the same way.

I have no doubt people will still make a living doing portraits and other paid photographic assignments, but the kind of art photography represented by the Clark Quay canopy shown above, would seem to be no longer viable as a profession, since it is so easy to do.

There was a time when taking photos like this requires an expensive camera that only professionals would have; taking the photo requires careful setting of the exposure parameters, and further processing had to be done in a darkroom, again with professional equipment. Today I can do this, without training though with a bit of trial and error, with an inexpensive camera and some software that can be downloaded from the web free (usually a trial copy with just some of the functionalities, with only professionals need the rest of the capabilities.)

(Portraits are harder because they require the shooter to judge the right moment to catch the expressions you want. News, especially sports events, require very quick reflexes. However, modeling and wedding photos these days tend to be replaced by videos)