Wide-angle lenses, depth of field, and point of focus

Yes, it's weeks 2 and 3 of the digital photography course -- and we actually got to take some snaps! We also learned about depth of field: the wider the aperture, the shallower the depth of field; the narrower the aperture, the deeper the depth of field. And one-third of the depth of field is in front of the point of focus and two-thirds behind. Confused? OK, let's take a look at it in practice with the help of an attractive model:

Photo 1: wide aperture, shallow depth of field. Shin is beautifully crisp and "large" (not fat) at the front of the picture; the background is pretty fuzzy.


Photo 2: slightly narrower aperture, deeper depth of field, the leaves are starting to become crisper.


Photo 3: much narrower aperture, much greater depth of field, the background is much clearer. Shin appears smaller and further away.



And last week, we headed out into the car park at Eastleigh FE college to take pictures using manual exposure and tripod. Underexposing a shot means it's too dark; you get a negative number popping up in advance on your settings screen, and you play around with the aperture and shutter speed until the camera recognizes that there will be enough light to take the picture. Overexposing means the picture will be too bright, but this time you get positive numbers on the screen. Obviously, at night, you need much slower shutter speeds -- sometimes up to 15 or 20 seconds, as we're not using flash. You can't hold a camera steady for that long, so you need to use a tripod. Although the car park wasn't the most exciting space, it was interesting to see just how well long exposures worked in terms of making use of all the available light. For example:



Best of all, though, is that having a better understanding of what you need to do makes it more enjoyable to go out and experiment. I was up at crack o' eight this morning to feed the cats, and noticed the beautiful light from the rising sun. I grabbed my camera and headed out in my pyjamas (don't worry, there was nobody around) to see what I could get. And while the telephone cables are annoying, this light is superb. I feel ... less incompetent!