3) Project: Focus. Exercise: Focus at different apertures - page 18.

Deciding the subject.

For this exercise, again it was fairly easy choosing a subject, using the Lego people as before.  This allowing me to continue with the same theme and all of the exercises on Focus have been completed using the same subject, making it very easy to review the results overall, enabling me to clearly understand what the camera is doing when the aperture and/or the focal length and angle of view is changed when taking a shot.

Setting up.

Once again this was relatively simple.  I placed the Lego people in a diagonal line on a small wooden box.  However, this time I took the shots in daylight, taking away any complications or difficulties obtaining the correct result when using flash indoors of an evening.  The light is sourced from my conservatory.

Equipment used.

Camera: Canon 500D.
Lens: Canon 18 - 55.
Flash: Not used.
Tripod: Mini tripod used.

Settings and results.

To obtain the following results, I actually took a total of 9 photos at various different apertures.  I have used both the widest and smallest apertures and one mid-point to provide clear results showing the differences in depth of field when using different apertures.  The focal point in this exercise is the Harry Potter Lego Figure, the 4th figure from the front wearing glasses.

IMG4097

IMG4097
Camera setting: AV - Aperture priority
Focal length: 55mm
Equivalent in 35mm: 87.7
Shutter speed: 1/60
Aperture: f/5.6 - Widest aperture (smallest number/shallow depth of field)
Flash: Not used
Metering: Matrix
ISO: 400
White balance: Auto

IMG4101
















IMG4101
Camera setting: AV - Aperture priority
Focal length: 55mm
Equivalent in 35mm: 87.7
Shutter speed: 1/50
Aperture: f/14 - mid-point aperture (middle number - slightly larger depth of field)
Flash: Not used
Metering: Matrix
ISO: 1600
White balance: Auto

IMG4105

IMG4105

Camera setting: AV - Aperture priority
Focal length: 55mm
Equivalent in 35mm: 87.7
Shutter speed: 1/8
Aperture: f/36 - Smallest aperture (largest number - largest depth of field)
Flash: Not used
Metering: Matrix
ISO: 1600
White balance: Auto

Findings.

It is now perfectly clear on how confusing aperture readings are, as the smallest number e.g. f/5.6, you would expect this to be the smallest aperture but it is not.  I now understand that the smallest aperture e.g. f/5.6 is indeed the total opposite of what you would expect and is the widest aperture with a shallow depth of field as you can see from the blurring around the edge of IMG4097.  Thus making a big number e.g. F/36 the smallest aperture with the largest depth of field, as can be seen by the lack of blurring around the focal point in IMG4105.

Conclusion.

The results from this exercise were indeed so much better for taking the photos in daylight and I have subsequently printed the photos to enable me to study the depth of field range based on the aperture used.  I feel that this is probably one of the most confusing technical aspects of photography, as it would appear that everything is the opposite of what you would expect, for instance a small aperture number is indeed the widest aperture with the smallest depth of field and the opposite can be said a large aperture number.  So in this respect this exercise has been extremely valuable to me, now allowing me to understand a little better aperture priority, how this affects depth of field and also how when the aperture changes due to the amount of light passing through, the shutter speed also subsequently changes to prevent over or under exposure.  Overall I am very pleased with how this exercise went and the result and understanding it provided.