Apertures With Clear Flash Bulbs; Apertures With Blue Flash Bulbs; Conversion Of Feet And Inches Into Metric Units - Kodak retinette User Manual

To find the correct aperture to use, divide the guide number by the distance between the flash and the subject. For
instance, suppose you find that the guide number of the bulb with the film in use is 160. If you then want to take a
photograph at a distance of 10 ft. from the subject, divide 160/10 = 16. Therefore, the correct aperture to use is
f16. Alternatively, if you want to use an aperture of f8 for any reason, then the correct flash distance is 160/8 = 20.
So the flash must be 20 ft. from the subject.
Distance
6 ft. (2m.)
8 ft (2.5m.)
10 ft (3m.)
12 ft. (3.6m.)
15 ft. (4.5m.)
20 ft. (6m.)
25 ft. (7.5m.)
30 ft. (9m.)
In bright rooms (kitchen, bathroom) or with films faster than 100 ASA, use next
smaller aperture. In very large rooms, at night outdoors or with slower 40-64 ASA
Many cameras are marked only in either the metric or British system, while
most of the tables in this book are also given only in one system. The table
1/8 in.
1/4 in.
1/2 in.
1 in.
2 in.
3 in.
4 in.
5 in.
6 in.
7 in.
8 in.
9 in.
10 in.
11 in.
1 ft.
2 ft.

APERTURES WITH CLEAR FLASH BULBS

G.E.,
Mazda,
G.E.C. No. 1
Philips:
PF 1
AG1
16
12.5
10
8
6.3
4.5
4
3.5
film use next larger aperture.

APERTURES WITH BLUE FLASH BULBS

(For 32 ASA Daylight Type Reversal Colour Film)
Distance
3½ ft. (1m.)
5 ft. (1.5m.)
7 ft. (2.2m.)
10 ft. (3m.)

CONVERSION OF FEET AND INCHES INTO METRIC UNITS

below shows at a glance equivalent lengths.
British to Metric
0.32 cm.
0.64 cm.
1.27 cm.
2.54 cm.
5.08 cm.
7.62 cm.
10.2 cm.
12.7 cm.
15.2 cm.
17.8 cm.
20.3 cm.
22.9 cm.
25.4 cm.
27.9 cm.
30.5 cm.
61 cm.
Mazda,
G.E., Philips:
G.E.C.: PF38
No. 5 Sylvania:
Philips: Press 40
PF 5 G.E.:
Sylvania: No. 11
Press 25
-- --
-- --
16 --
16 16
11 12.5
8 10
6.3 8
5.6 6.3
PF 1/B
No. 1B
AG 1B
f16
f11
f8
f5.6
Metric to British
0.5 cm.
1 cm.
2 cm.
3 cm.
4 cm.
5 cm.
6 cm.
7 cm.
8 cm.
9 cm.
10 cm.
12 cm.
15 cm.
20 cm.
25 cm.
30 cm.
Philips:
PF 60
G.E.:
No. 22
Sylvania:
No. 2
--
--
--
--
16
12.5
11
9
PF 60/97
No. 22B
--
f22
f16
f11
3/16 in.
3/8 in.
13/16 in.
1 3/16 in.
1 9/16 in.
1 15/16 in.
2 3/8 in.
2 3/4 in.
3 1/8 in.
3 1/2 in.
3 15/16 in.
4 3/4 in.
5 7/8 in.
7 7/8 in.
9 13/16 in.
11 3/4 in.