Setting the Exposure
Magnification and Effective f-number
The aperture displayed by the camera assumes that the focus is set to infinity. The actual aperture (effective f-number) becomes darker (effective f-number increaases) at closer focusing distances (magnification increases). This does not cause exposure problems for normal picture-taking. However, for closeup photography, you cannot ignore the change in the effective f-number.
When you use a handheld exposure meter to set the exposure, you must take into account the exposure factor shown in the following table.
Use the following formula to calculate the effective f-number:
Effective f-number = f-number x (Magnificcation + 1)
For example, if the aperture displayed by the camera is f/2.8 and the magnification is 1x, the effective f-number will be f/5.6.
| Magnification |
1x |
2x |
3x |
4x |
5x |
| Effective f/No. |
5.6 |
8.4 |
11.2 |
14.0 |
16.8 |
Setting the Exposure
The correct exposure for a close-up shot largely depends on the subject. Therefore, try to bracket the exposure for the same subject.
with the EOS-1Ds Mark III, 1Ds Mark II, 1Ds, 1D Mark III, 1D Mark II N, 1D Mark II, 1D, 1, 1N/DP/HS, and 1V/HS TTL autoexposure metering is possible from 1x to 5x. Select the desired picture-taking mode and check the shutter speed and aperture.
With Other EOS Cameras
Since there will be a slight exposure error, using AE metering is not recommended. Take test shots first or use a handheld meter to determine the proper exposure based on the effective f-number. If you use the f-number displayed by the camera, use the exposure factor in the table below to convert it.
| Magnification |
1x |
2x |
3x |
4x |
5x |
|
Exposure Factor
(stops)*
|
+2 |
+3⅓ |
+4 |
+4⅔ |
+5⅓ |
| +2 |
+3 |
+4 |
+4½ |
+5 |
* Upper values: 1/3 stops. Lower values: 1/2 stops.
Effective f-number for the Magnification and Camera's f/No.
For Cameras Displaying ⅓ Stops
| f-number |
|
1x |
2x |
3x |
4x |
5x |
| 2.8 |
5.6 |
8.4 |
11.2 |
14 |
16.8 |
| 3.2 |
6.4 |
9.6 |
12.8 |
16 |
19.2 |
| 3.5 |
7 |
10.5 |
14 |
17.5 |
21 |
| 4 |
8 |
12 |
16 |
20 |
24 |
| 4.5 |
9 |
13.5 |
18 |
22.5 |
27 |
| 5 |
10 |
15 |
20 |
25 |
30 |
| 5.6 |
11.2 |
16.8 |
22.4 |
28 |
33.6 |
| 6.3 |
12.6 |
18.9 |
25.2 |
31.5 |
37.8 |
| 7.1 |
14.2 |
21.3 |
28.4 |
35.5 |
42.6 |
| 8 |
16 |
24 |
32 |
40 |
48 |
| 9 |
18 |
27 |
36 |
45 |
54 |
| 10 |
20 |
30 |
40 |
50 |
60 |
| 11 |
22 |
33 |
44 |
55 |
66 |
| 13 |
26 |
39 |
52 |
65 |
78 |
| 14 |
28 |
42 |
56 |
70 |
84 |
| 16 |
32 |
48 |
64 |
80 |
96 |
For Cameras Displaying ½ Stops
| f-number |
|
1x |
2x |
3x |
4x |
5x |
| 2.8 |
5.6 |
8.4 |
11.2 |
14 |
16.8 |
| 3.5 |
7 |
10.5 |
14 |
17.5 |
21 |
| 4 |
8 |
12 |
16 |
20 |
24 |
| 4.5 |
9 |
13.5 |
18 |
22.5 |
27 |
| 5.6 |
11.2 |
16.8 |
22.4 |
28 |
33.6 |
| 6.7 |
13.4 |
20.1 |
26.8 |
33.5 |
40.2 |
| 8 |
16 |
24 |
32 |
40 |
48 |
| 9.5 |
19 |
28.5 |
38 |
47.5 |
57 |
| 11 |
22 |
33 |
44 |
55 |
66 |
| 13 |
26 |
39 |
52 |
65 |
78 |
| 16 |
32 |
48 |
64 |
80 |
96 |
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- With the EOS-1 and EOS-1N/DP/HS, fine spot metering cannot be used because an exposure error will result.
- During remote control shooting, etc., when you take your eye off the eyepiece, cover the eyepiece with the eyepiece shutter or cover. Otherwise, stray light may enter the eyepiece and affect the proper exposure reading.
|
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- With the EOS-3, using a Laser Matte focusing screen will enable AE metering at all magnifications from 1x to 5x.
- Using aperture-priority AE (Av) or Manual (M) picture-taking modes are recommended as it is easy to adjust depth of field and exposure in these modes.
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