Light and Shade II

Ah, where to begin?

Lots of  “experts” state that a 50mm focal length is a “standard” (or “normal” in Americanese) lens “because it’s a perfect match for the human eye”. When challenged, they assert that it has the same angle of view as a human eye. Which is of course utter balderdash. The human eye has an angle of view very very much wider; what IS true is that a focal length equivalent to the diagonal of the format in use gives perspective and relative magnification that pretty much matches the human eye. But that’s not 50mm; it’s 43.5mm for the formats in question. The reason why 50mm is considered the standard is pretty much that that’s what was available to Oskar Barnack when he designed the Leica.

Another one that seems to have a lot of supporters, yet how many of them have actually thought it through?

The argument goes that it’s crazy to put all your eggs in one basket, because if the card gets corrupted or your camera gets stolen, you lose the lot.

Now let’s just take a look at this one: firstly, when are cards most likely to be corrupted? When the read or write cycles are disrupted, that’s when. And when is that most likely? Whilst changing a card. So what’s the best way of tackling the risk? According to the myth, by limiting the impact of the event, but it’s pretty obvious that it’s better to avoid the event – by not changing cards so often. Which requires a bigger card…

But say the worst happens, and your card is corrupted. In my experience, it’s rare that the whole card is actually corrupted – in fact I’ve never known it. But even if it is, there are plenty of data recovery programs out there that will save the day with most images. So the chances of losing all your pics if your large card gets corrupted are miniscule, whereas your chances of losing some images are significantly multiplied by using lots of cards.

Now let’s look at loss: yes, loss of camera/sole card is catastrophic – so I would recommend backing up images at the end of the day onto a separate device. And carrying a spare card! But to be honest, if you’ve got lots of cards to look after, aren’t the risks of losing one far greater than if  you have less to worry about?

Again, this is one for people to make their own minds up on – but after genuinely thinking about it, not blindly accepting dogma.

This is one that is almost inevitably put about by 4/3 devotees, who can be a very strange lot at times. However, the heart of the myth is that there’s little difference in physical size and further that the difference is eroded in practice due to cropping required to make the images from 3:2 format cameras fit standard paper sizes – one site claims APS-C is only effectively 14% bigger than 4/3.

So, let’s look at the facts, shall we?

The dimensions of Canon’s APS-C sensors are 22.2 x 14.8 mm – that’s 328.56 sq mm. (I use Canon for a comparison as the dimensions of the imaging area are known – Nikon quote total sensor dimensions.)
The dimensions of the 4/3 sensor are 17.3 x 13.0 mm – or 224.8 sq mm.

So the difference is 103.66 sq mm, which means that the APS-C sensor is 46% bigger than the 4/3 one.

Now, let’s look at common paper sizes.

6″x4″ plainly is in a 3:2 ratio. 7″x5″? Well, that’s 2.8:2 or 4.2:3, so cropping on either format.
10″x8″? 2.5:2, or 3.75:3. A4? 2.83:2 or 4.24:3. And so on – it’s clear that there’s no magic advantage for 4/3 for popular sizes.

So it’s clear that unless you’re incapable of elementary maths, 4/3 suffers from a pretty significant size disadvantage compared to APS-C. Does that matter? Well, it means that for a given pixel count, the pixels have to be considerably smaller, leading inevitably to greater noise.

Well, absolutely, no, the choice of format doesn’t dictate creativity. What it does do is define the bounds of creativity, at least in certain areas. So if you want to use selective focus with a wideangle perspective, forget doing it on a compact digital, for instance. If you want golfball-sized grain in a normal print size, don’t use a large format camera. Common sense, surely?
I’ve used everything from Disk cameras to 5″x4″ for film, and a VGA Phonecam through to full-frame for digital – each has a place, and each places different bounds on creativity.

Ah, the biggie. The belief that the camera somehow records the truth. It seems to be modified these days by an understanding that images may be altered, but only if they’re digital…but I’ll leave that one for another Myth.
Has the camera ever told the truth? Well, it captures whatever’s in front of it for the period that the shutter is open, but is that the truth we would recognise? Think about all the choices a photographer makes: let’s start with choice of black and white or colour. Black and white simply isn’t how we perceive the world (except in very low light), so how can it be true on any level? Even colour is tricky – it appears that we all perceive colour differently, for one thing, but what about producing pastel or super-saturated shots? Next, filters; a polariser certainly gives a different image to one we can see with bare eyes, for a start. Choice of lens and viewpoint to change perspective – not something we can easily do with the eye. Selection of focus point and depth of field – the photographer can manipulate the image to look very different to anything that could normally be seen. Use of shutter speed – we don’t see water blurred the way it can be portrayed with a long exposure, nor can we freeze very fast movement – the camera can. Finally (for now) there’s the response of the recoring medium – very few can manage the contrast range that the eye can.

So in the camera we have an instrument that faithfully records what’s presented to it, but whose resulting images don’t necessarily portray any kind of reality that we might recognise.

It’s often said that you don’t need extra lenses because the best zoom is your legs. Again, there’s quite a bit of truth in it – sometimes if you need to get more in a shot, you can just move backwards, or move closer to fill the frame. Further, you have a chance of finding a better viewpoint than the original one. However, what if you want to use a particular perspective effect that requires a certain viewpoint? Or if you can’t physically get closer or move further away? In such circumstances, if you’ve not got the appropriate lens available, you’re stuffed.

Established photo orthodoxy says that you should always fit a filter to every lens you own for protection. So what do I say? Piffle and poppycock, that’s what.

There are perfectly good arguments both ways – and a few specious ones, too. In favour: Acts as an “invisible lens cap”, prevents sticky fingers and wind-bourne debris from coming in contact with the lens. Can’t (and don’t) argue with that. Filters out UV (if UV or skylight filter) – helpful if there’s a significant amount of UV, although generally not actually required with most lenses. Still, can’t hurt. Provides impact/scratch protection. This is the one I really don’t agree with – firstly, the filter is frequently some distance from the front element, and thus more prone to contact with the offending article than the lens element would be, and secondly, the ONLY incidence of lens element damage I’ve ever had came from a filter which shattered when I dropped the lens (on a tram at Crich Tramway Museum) and a shard of glass scratched the front element. That was over 20 years ago, and I’ve not had a scratched element since – and I wouldn’t claim to be that careful with lenses. Easier and safer to clean a filter than a lens element. Well, it’s safer, for sure, but I always found filters needed a lot more frequent cleaning and were more prone to smearing than lenses. Protects the filter ring from damage when the lens is dropped/bashed – sometimes it does, sometimes it causes more damage, but on balance it probably works, IMHO. Against: Damage – as above. I’m not claiming it’s any more or less prevalent than without a filter, simply that the possibility needs to be considered. Flare. Extra glass/air surfaces increase internal reflections and thus veiling flare. In truth, with multicoated filters it’s not a huge problem except when shooting contre-jour, but it’s a consideration. Cost. Good filters cost quite a bit, especially if you have a few lenses. The insurance option may well be more cost-effective, and provides other benefits. Damage to filter ring – filters can damage, be cross-threaded etc. Not a huge concern, but an argument for filters in brass mounts, which tend to jam a lot less than some others. Danger of vignetting with wideangles when stacked with other filters. Reduction in resolution due to extra glass – frankly, I doubt if many, or any, users could spot any such reduction. Alternatives: – lens caps provide better protection when not shooting, less risk of damage than from a glass filter, and no optical loss when removed to take a picture. But they’re more fiddly and easily lost, of course. Rigid lens hoods provide excellent protection against drop damage and make it hard (but not impossible) for anything to touch the front element. Conclusion So, am I saying you shouldn’t use protection filters? No, certainly not. What I AM saying is that you should consider all the aspects and decide for yourself – not blindly follow the advice either of those who say they’re essential or those who say they’re more trouble than they’re worth. It’s not thinking through all the arguments that I think is dangerous – when you have, at least you’ve come to an informed decision. Personally, I rarely use them, but generally carry them – I do use them if there’s salt spray, sand or dust storms etc. I use rigid hoods and lens caps all the time – and insurance.

Many insist that you should always stick to the main compositional rules – the rule of thirds, or the golden mean – and that the subject should never be placed in the centre of the frame. Well, these rules are sensible enough, but are meant to be broken – often a shot that breaks all the rules can be all the more striking for it.

Everyone knows Henri Cartier-Bresson was such a genius he always pressed the button at the decisive moment, right? Well, wrong, actually – he was at heart a photojournalist, and would work a scene to the max to get the shot he wanted – and he wasn’t afraid to set shots up.

Who says you can’t? Why, a lot of landscape photographers. Why not? Because the light’s not interesting. So what is the result? Every shot is taken in the same light – now is THAT interesting?

Of course the light before, at and just after dawn and dusk is magical, and can produce terrific results. But any directional light can bring out the modelling of a landscape, and sometimes overhead sun with harsh shadows produces a terrific effect. And then there’s bad weather – there’s nothing quite like a stormy sky to add interest, and it really doesn’t matter what time of day it is. But those who believe this myth miss out – I feel sorry for them.