How to play with the aperture setting and understand dof

For those new to photography, the aperture setting controls the width of the aperture when exposing the sensor (or film) to light. These are stated using a letter prefix eg f2, f4, f8, f16, f32 and so on. The larger the number the smaller the width of the aperture (and hence less light is let in during the same time period). That sounds counter-intuitive, but once you realise that the number is really the width of the aperture as a fraction of the focal length of the lens it all makes sense, so f2, f4, f8, f16, f32 represents widths of 1/2, 1/4, 1/8, 1/16, 1/32 of the focal length of the lens... presto! And the reason why the aperture is getting smaller now makes sense.

Ok so the f-stop number controls the width of the aperture, but it has a secondary effect - it affects  the depth of field (dof) in the image. Simply put, the dof is the range (distance) of sharpness in the image. f4 has a much smaller dof than f8 which is smaller than the dof created using f16 and so on. (note: there are two other ways to affect the dof, they are how close we are to the image and the zoom we use to view the image - more on these two elements later)

Below are some shots taken of the same scene using f4, f8, f16, and f32. I experimented with where to place the depth of field within the frame, ie a foreground sharp leading to a blurred background, or having the background sharp with a blurred foreground, or having everything in focus.

Background was in focus using f16

Background was in focus using f8. Notice the smaller dof creates more blurr in the foreground

Foreground in sharp focus using f4 making everything else blurr

Foreground in focus using f8 creating blur in the background

Everything in focus using f32.

Notice that the dof changes when I use f4, f8, f16 or f32, but I can control where that range of sharpness is located. And in the above images, changing the aperture setting and where the dof will be, we create images that tell a different story each time.

I took around 100 shots of this scene using different permutations of settings; but, rest assured, once done I did enjoy the cool water in this gorgeous part of WA (Wharton Beach).

Have fun ... I'd love to hear how you got on.  

Rain on my balcony

A recent day of rain and finally I get to shoot something with water in.

Fremantle

Some shots around the Fremantle Maritime Museum. Thinking out side of the box in a couple.

Black and white images

I do love black and white images. The mood created by the tones can be more powerful than the colour version.

So the next time you take a shot, think about converting to black and white. And who knows, you may turn an ordinary shot into a keeper.

To get an idea of whether you think your shot would look better in b&w, look at the image (or its histogram) and determine if there is a wide distribution of tones from dark to light. A wide tonal range is important here.

Let me know how you get on.

have fun :-)

Lightning shots

Some recent lightning shots. Can you spot the plan flying in the foreground?

This was my first attempt at getting some shots with my new camera.