Visit Part 1: Photography Basics I

Main Topic of today’s Post is Depth of Field (DOF) – something that many know of vaguely, some
as a major component of their composition, and some have no idea what so ever, on what it is.

Well – the simpler your camera is – the less you can influence it. With full automatic cameras you
really do not have much of a say, same goes for most automatic settings in more advanced cameras.

So what the heck is DOF?

DOF describes the area in the picture your camera can deliver in sharp focus. It depends on focal length, the lens itself and the aperture, you or your cameras automatic settings have chosen.

Main factor however is the aperture. As a rule of thumb you can bank on the following fact.

Low aperture value = shallow DOF

High aperture value = wider DOF

Why should that stuff be important to me, when I shoot images?

Working the Depth of field properly has many benefits, most of them reveal themselves only, when you’re at home reviewing the images you shot. The situations where your image profits most from good usage of the DOF are Macros and Portraits, but basically every shot you take deserves a consideration.

M A C R O: Let’s take the example of a Dragonfly shoot. You will often see that parts of Dragonfly images are crisp – others are blurred – which is a result of a very shallow DOF. The remedy would be to choose the highest aperture value, both camera and available light allow, to increase the range of sharpness.

As you can see – the image on the left uses a large aperture (f22) and has almost the entire Dragonfly in focus, where a low aperture (f5.6) in the image on the right allows little more than the body to be in focus.

That is a direct impact of the selection ou make prior to your shot – as can be the creative use of the knowledge, that your available DOF is very shallow in your shoot – so use what you got to your advantage!

See example below!

As you see it’s a macro. The focus is just so on the eye, well knowing that the DOF is that shallow, that
there would be little chance to get the whole bird sharp. So for this shot I went the other way and used the lowest aperture available – in this case f 3.5.

P O R T R A I T: In portraits your objective usually is different than it is with closeups or a macro. Here you want to focus on the head of your “victim”, isolate it from the background. A wide DOF would bring the background in focus ( or at least partially), which would be quite an undesired effect.

In the comparison images below you see how the aperture effects your image at different settings, and with different focal lenghts. To your left is the image taken with 70mm, to the right with 300mm.

Again a rule of thumb that comes in handy for general knowledge: The longer your focal lenght, the narrower the DOF will become. In other terms – with a superwide lens and high aperture you will probably have the whole field of view tack sharp.

What’s quite easy to spot on the examples is that a fully blurred background is what you want for a portrait.
Is it (the background) more in focus, it distracts from your object and makes the image busy.

Because most cameras are not able to provide an actual preview, on how the DOF will actually pan out
in your image, your tool and your weapon in the fight for good images is a) the knowledge of DOF, and – that is my suggestion – you testing it yourself, with your camera. Best subject to get a feel for how

DOF impacts your images and how your lens works is a fence row. Focus on one post pretty much in the middle,while standing in a steep angle to the fence, and then go through the paces, changing the aperture one stop at a time with every image. This will help you in practical terms, because then you will see that at focal lenght X and aperture Y you have for example 2 feet of an area that your lens will be able to deliver sharpeness.

Keeping that in mind, when shooting, will help you deliver better images.

Good luck!

And if you have a question – don’t hesitate to ask!