will see more than you do. Sometimes it will see less. Sometimes it will see differently. And sometimes it will do all three! Today, with digital cameras, it’s much easier to compare what we saw with what the camera recorded. It really is worth looking attentively at those playback images, especially with important shots, to see how they measure up. For one thing, if they don’t look quite how you wanted, you may be able to do something slightly differently and shoot again. For another, it all helps to build up an understanding of how the camera sees.
Life through the viewfinder
We’ve already given an example of the camera seeing more, the friend seen across a crowded room. Human beings tend to see what they are interested in: cameras are not so selective. Sometimes the result is that your intended subject almost disappears into its surroundings – like your friend into the crowd. At other times the result may be that the intended subject is sitting in the middle of the frame but surrounded by acres of empty space.
The answer to these problems is learning to use the viewfinder. The ‘point and shoot’ way is to see the subject, aim the camera and press the button. The photographer’s way is to look through the viewfinder and see the whole image before composing the best shot. It is rather like the difference between looking through a window and looking at a picture. The view through a window has three dimensions and the eye tends to home in on whatever is most interesting. A picture is in two dimensions and it’s relatively easy to see it as a whole. If you’re not using a viewfinder at all, but looking at the screen on the back of a digital camera, then what you’re looking at is more picture-like already.
But whether you’re looking at a screen or through a viewfinder, you still need to be aware of two things: the boundaries of the frame, and what’s contained within them. This awareness develops with practice, and with digital cameras you can help it develop by looking carefully at playback images too.
However, the sad fact is that, however carefully you look at the screen or the viewfinder, what you see still isn’t necessarily what you get. To complicate matters further, there are different types of viewfinder, which behave quite differently, as well as the camera-back screen. In simple terms, there are two main types of viewfinders. These are direct-vision and reflex.
Direct-vision finders are found on compact cameras – if they have a viewfinder at all; many digital compacts don’t bother. A direct-vision viewfinder is essentially just a small window. The window’s frame may correspond to the borders of the image you’ll shoot, or there may be a marked area within the window to show the actual picture area. In this case, round the edges of the finder you can see stuff which won’t appear in the final picture.
Because looking through a direct-vision finder is like looking through a window, your eye can adjust to focus on close or distant objects. Just as when you are looking around you normally, whatever you look at appears in focus, so you get the impression that the whole scene is in focus. However, it’s by no means guaranteed that everything in the final shot will be in focus: things that seemed clear in the viewfinder may be blurred, even blurred beyond recognition.
Ribblehead Viaduct, North Yorkshire (Jon) When looking at the SLR finder the eye stays focused at a constant distance. This can weaken our sense of depth, but the third dimension is always there and in some shots it’s immensely important
With a reflex finder, and with the LCD screen, you actually view through the camera lens – the same lens that takes the picture. In a single-lens reflex (SLR) camera the image is relayed to your eye by a mirror that flips out of the way when the shutter is pressed. We can lump reflex viewfinders and camera-screens together as ‘through the lens’ (TTL) finders. Surely TTL viewing means that what you see matches the photo you’ll get? You can certainly be forgiven for thinking that it should, but it’s not that simple. Sometimes it gets very close, but at other times it doesn’t.
Actually, the SLR finder image is a bit of an illusion. It is not a three-dimensional image; you aren’t literally looking through the lens. What you really see is the image projected by the lens on the focusing screen. When you look directly at the world, your eye has to refocus to look at distant or near objects (even although we often don’t notice that it’s happening). When looking at the SLR finder the eye stays focused at a constant distance (of course the lens may have to refocus to give a sharp image of things at different distances). And with your eye to the viewfinder of an SLR, the image becomes your entire field of view, and there’s a tendency to look at it piecemeal rather than in its entirety.
Next time you look into an SLR viewfinder, think about the fact that you are looking at a projected image which has no more real depth than the image on your computer screen. Let’s hope that this helps to focus the mind on the image as an image.
Another problem is that the viewfinder doesn’t necessarily show you the full picture area. Unfortunately, a true 100% viewfinder image is largely the preserve of professional SLRs – most others shave a good 5–10% off what you actually get in the image. Digital camera screens are much more likely to give closer to 100% view, but you should always check.
There’s an even more significant reason why what you see in TTL viewing isn’t always what you get. This is all to do with something called depth of field. We’ll explore this in more detail in Chapter 3, but for now, depth of field simply means what is in focus and what isn’t. If the image shows one object sharply focused, with everything else out of focus, depth of field is small. If, however, objects both nearer and more distant also appear in focus, depth of field is large.
Druidston, Pembrokeshire (Chiz) Focus is on the closest grasses, depth of field is small, and distant landscape soft
Focusing and depth of field: what’s sharp and what’s not
While a direct-vision finder gives you the impression that everything is in focus, with an SLR you can often see that some things are in focus and some aren’t. Focus on a nearby leaf and the distant landscape may well appear soft. This could be a good thing if you want to concentrate attention on that leaf. The problem is that when you take the shot, the background sometimes looks much sharper than it did in the finder or screen. In other words, depth of field in the shot is much greater than in your TTL view.
With direct-vision finders, the opposite is often true. When you view, everything appears in focus but this is rarely, if ever, matched by the final shot. With a little luck the main subject is still in focus, but foreground and background may not be. In this case, depth of field is much less than it appeared in the viewfinder.
It’s not hard to understand that a direct-vision finder doesn’t match the final photo. You’re looking through a separate window, not through the camera lens. But in TTL viewing you are looking through the camera lens, so surely what you see should match the final photo?
Well, no. You are looking through the same lens, but it isn’t necessarily doing exactly what it does when it takes the photo. Specifically, the aperture is often different. When you view, normally the aperture is at its widest and depth of field is minimal. When you take the shot, however, the camera often sets a smaller aperture, causing depth of field to increase. Camera manufacturers set things up this way as it lets the most light in at the viewing stage, and therefore gives the brightest image in the viewfinder (easier to see than a darker one!), regardless of the settings you use to actually capture the shot.
Once you know this, it becomes very easy to check the image on playback and change the aperture if required to reduce or increase the depth of field. Or even use a button called depth-of-field
