Project 3 : Focus with a fixed aperture

Posted on:

July 08 2009

Posted by:

moggsterb

Posted in:

Projects

I knew what to expect with this project. It’s something I’ve done before.

Basically, the brief was as follows: Find a subject with a long depth and take 3 shots at different apertures:

• Shot 1 – widest aperture
• Shot 2 – mid-point
• Shot 3 – smallest aperture.

This is my second attempt at this project, originally I went into the park (as in project 2) and with the camera on tripod produced 3 shots of a woodland path.

However, when I got the shots back onto my pc, the focusing effect wasn’t as apparent as I’d have liked (ie particularly on shot 2 and shot 3). This was mainly down to the choice of subject, (leaves and foliage), where the sharpness of image was difficult to detect.

Instead, I set up a shot at home on the dining table. I arranged a line of spirit bottles to form a scene with great depth. I chose this as my subject because sharpness would be easy to measure on the bottles’ labels.

For the three shots, I focused on the nearest bottle. By doing this, I would be very easy to spot the breakdown of sharpness over the three shots.

The first shot, taken at the widest aperture (F3.5) has a very small depth of focus. The background is massively blurred. The Jamesons is just about in focus but past that there is blurring. Shooting at wide apertures such as this is ideal for portrait photography.

For the second shot, taken with the a mid-point aperture (F9), the depth of focus has increased. The focus now extends to the Havana Club.

Finally, the third shot, taken with a narrow aperture (F22), the entire shot is in focus.

In this particular set of shots, I prefer the widest aperture (F3.5). I think the shallow depth of focus, adds interest to the shot. However, the choice of aperture depends very much on the subject.

In Bryan Peterson’s book “Understanding Exposure“, he talks about choice of apertures. Wider apertures tend to isolate (rendering only a limited, selected amount of visual information in sharp focus) and narrow apertures tend to tell a story (rendering all the visual information within a great depth in sharp focus)

He has a name for F8 through to F11 apertures – Middle of the Road Apertures (or “Who Cares?” apertures), and concludes “who cares what aperture you use when shooting compositions where depth of field concerns are minimal at best? You should! And ironically, you should use “who cares?” apertures, if you want critical sharpness and great contrast.”