MR. W.K.  BURTON’S TABLE OF COMPARATIVE EXPOSURES
------------+--------------------+-------------------+------

-------------------
|                    |      Badly lighted|      Portraits in bright
|                    |         interiors,|      diffused light
Aperture    |                    +------------+  up  |      out of doors.
calculated  |     Landscape with |     Fairly |  to  |     /
on the      |   heavy foliage in |    lighted |      |    /      Portraits in
standard    |        foreground. |  interiors |      |   /       studio light
system      +------+-------+     +------+     |      |   |      /
of the      | Sea  |Open   |     | Under|     |      |   |     /   Portraits
Photographic| and  |land-  |     |trees,|     |      |   |     |   in ordinary
Society.    | sky. | scape.|     |up to |     |      |   |     |   room.
------------+------+-------+-----+------+-----+------+------

+-----+------
|  sec |  sec  | sec | m  s | m  s| h  m |  sec | m  s| m  s
No. 1,      | 1/160|  1/50 | 1/8 | 0 10 | 0 10| 0  2 |  1/6 | 0  1| 0  4
or f/4      |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 2,      | 1/80 |  1/25 | 1/4 | 0 20 | 0 20| 0  4 |  1/3 | 0  2| 0  8
or f/5.657  |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 4,      | 1/40 |  1/12 | 1/2 | 0 40 | 0 40| 0  8 |  2/3 | 0  4| 0 16
or f/8      |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 8,      | 1/20 |  1/6  |  1  | 1 20 | 1 20| 0 16 | 1-1/3| 0  8| 0 32
or f/11.314 |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 16,     | 1/10 |  1/3  |  2  | 2 40 | 2 40| 0 32 | 2-2/3| 0 16| 1  4
or f/16     |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 32,     | 1/5  |  2/3  |  4  | 5 20 | 5 20| 1  4 | 5-1/3| 0 32| 2  8
or f/22.627 |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 64,     | 2/5  | 1-1/3 |  8  |10 40 |10 40| 2  8 |10-1/2| 1  4| 4 15
or f/32     |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 128,    | 4/5  | 2-2/3 | 16  |21  0 |21  0| 4 15 |  21  | 2  8| 8 30
or f/45.255 |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------
No. 256,    |1-1/2 | 5-1/2 | 32  |42  0 |42  0| 8 30 |  42  | 4 15|17  0
or f/64     |      |       |     |      |     |      |      |     |
------------+------+-------+-----+------+-----+------+------

+-----+------

The estimation of this correct exposure is probably the greatest difficulty in photography, and it is