Interpretation of Photographs

Lessons

Senior 6 · Geography

Interpretation of Photographs

4 lessons

Lesson 3 of 4

Sketching Photographs by Reduction and Enlargement

22 min

Keeping the lines that matter

A photograph holds millions of details; a sketch keeps only the lines that carry the geography: the shape of the land, where the trees and fields are, where people live and move. Drawing it forces you to look properly, and a labelled sketch is often worth more marks than a paragraph, because it shows at a glance that you have seen how the parts of the landscape fit together. Examiners usually fix the size of the sketch, so you must also be able to reduce or enlarge the photograph's frame correctly.

Definition

Sketch of a photograph (also called a précis sketch or landscape sketch): a simplified line drawing of a photograph, in the same proportions, showing only its main features, with labels and a title. It is not a work of art: no shading of the sky, no drawing of every leaf.

Skyline: the line where the land (or the tallest objects on it) meets the sky. It is usually the first line drawn.

Getting the frame right

The frame of the sketch must have the same shape as the photograph: its length and width are both multiplied by the same factor $k$ .

k = \frac{\text{length of the sketch frame}}{\text{length of the photograph}}

$k < 1$ reduces, $k > 1$ enlarges. The areas change by $k^{2}$ , as with maps in Unit 1.

Worked example 1: reducing

Problem. The photograph above is printed 24 cm long and 16 cm high. Draw a frame for a sketch reduced to three quarters of its size. How does the area of the sketch compare with that of the photograph?

Solution.

\text{length} = \tfrac{3}{4}\times 24 = 18\ \text{cm}, \qquad \text{height} = \tfrac{3}{4}\times 16 = 12\ \text{cm}

\frac{\text{area of sketch}}{\text{area of photograph}} = \left(\tfrac{3}{4}\right)^2 = \frac{9}{16}

Check the shape: $\frac{24}{16} = \frac{18}{12} = 1.5$ , so the proportions are kept.

Worked example 2: enlarging to fit

Problem. A photograph 9 cm long and 6 cm high must be sketched so that the frame is 15 cm long. Find the enlargement factor and the height of the frame.

Solution.

k = \frac{15}{9} = \frac{5}{3} \approx 1.67, \qquad \text{height} = \frac{5}{3}\times 6 = 10\ \text{cm}

Drawing the frame 15 cm by 6 cm, or 15 cm by 15 cm, would squash or stretch every feature.

Drawing the sketch, step by step

Draw the frame to the size you worked out.
Divide the photograph and the frame into nine with light lines at the thirds, so that each feature can be placed in the matching section.
Draw the main lines first: the skyline, then the outlines of hills and valleys, the edges of woodland, and rivers and roads that run through the scene. Figure 2 shows this stage.
Add the features asked for, section by section, using simple outlines and symbols: a few crowns for a wood, short parallel lines for terraces, small boxes for houses.
Label each feature, with a straight arrow or line to it; labels may go in the empty sky or outside the frame.
Finish with a title and the words "not to scale"; say whether the sketch is reduced or enlarged, and by how much.

Figure 2: stage 1. The frame is divided into nine, and only the six main lines are drawn.

Figure 3: the finished sketch. Each feature sits in the same section as in the photograph: the woodland mainly in the left middle ground, the terraced hill across the centre and right middle ground, and the banana plants across the foreground.

Warning

Common mistakes

Wrong proportions. A frame of the wrong shape pushes every feature into the wrong place.
Art instead of geography. Shading, clouds and single leaves take time and earn nothing; clear outlines and good labels earn the marks.
Starting with the details. Draw the skyline and main relief lines first, then fit everything else between them.
Unlabelled features. An unlabelled line is ambiguous: is it a road, a river or a field edge?

Tip

Exam technique. Read the question before you draw. If it asks for "relief and land use", show hills, slopes and valleys, and the crops, woodland and settlement; leave out the rest. Use a sharp HB pencil, and keep the nine-section lines faint.

Mr Gedge's Geography Channel: "How to draw a Precis Sketch from a photograph". A step-by-step demonstration of sketching from an oblique photograph and from a view taken from above. Compare the order of the steps with the list in this lesson.

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Practice

A photograph measures 20 cm by 12.5 cm. Give the frame size for a sketch reduced to 60%.
A 12 cm by 8 cm photograph is to be sketched in a frame 18 cm long. Find the enlargement factor and the frame's height.
By what factor does the area change when a photograph is sketched at 1.5 times its size?
Why is the skyline usually drawn first?
In which sections of the terraced-hill photograph are (a) the houses on the hilltop, (b) the dug plot of bare soil?
Draw your own sketch of the Kigali hills photograph from Lesson 2, reduced to half its size, and label the relief, the settlement and the vegetation.
A classmate's sketch has the woodland in the centre foreground. Explain what went wrong and how to prevent it.

Show answersHide answers

$0.6\times 20 = 12$ cm by $0.6\times 12.5 = 7.5$ cm.
$k = \frac{18}{12} = 1.5$ ; height $1.5\times 8 = 12$ cm.
${1.5}^{2} = 2.25$ : the area is 2.25 times larger.
It is the longest, clearest line and it fixes the shape of the land; the other features are drawn in relation to it.
(a) The centre (and right) of the background, just above the middle ground, along the top of the hill. (b) On the line between the right middle ground and the right foreground.
Check your sketch: two steep-sided hills filling the left and right of the middle ground and foreground, dense housing on the valley floor in the centre, tall buildings on the distant ridge in the left and centre middle ground, sky across the top third, trees on the steep slopes; frame half the length and half the height of the photograph.
The feature was placed in the wrong section, probably because the sketch was drawn without dividing the frame and the photograph into nine. Draw the nine-section lines on both and place each feature in the matching section.

Summary

The sketch frame keeps the photograph's proportions: both sides are multiplied by $k$ ; the area by $k^{2}$ .
Divide both into nine; draw the skyline and main lines first; then the features asked for.
Label every feature, add a title, say "not to scale" and state the reduction or enlargement.

Sources and credits

A hill with terraces: Peace Batuma, Wikimedia Commons, CC BY-SA 4.0. Figures 2 and 3 are drawings by Ganzaa traced from this photograph.

The text, worked examples and exercises were written by Ganzaa.

Video: "How to draw a Precis Sketch from a photograph", Mr Gedge's Geography Channel, embedded from YouTube.

This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.

1Keeping the lines that matter

2Getting the frame right

3Drawing the sketch, step by step

Keeping the lines that matter

Getting the frame right

Drawing the sketch, step by step