The second method is to turn the Auto/Manual Switch
(23)
to the "M" position which has the effect of manually
closing the aperture down to the selected lens opening --this is probably easier to master than the first method
but you must remember to return the Switch after use to the "A" position ready for normal operation.
Using the depth-of-field scale (13)
The scale consists of the aperture numbers repeated each side of the Distance Index (10) and shows, at any
given focus distance, the nearest limits and furthest limits of acceptable sharpness. Taking the Helios 44M lens
as an example, if this is focused at 4 meters, the depth-of-field stretches from 3 meters to 6 meters at an aperture
of f/5.6 while at an aperture of f/16 objects from 2 meters to infinity (oo) will be acceptably sharp in the final
picture. Note: For the sake of reading clarity some figures are omitted from the scale; however, its a simple
matter to 'fill in those missing if you remember they follow the aperture sequence exactly, with those
proceeding left from the index
(10)
showing the near limits of sharpness, and those proceeding right showing
the far limits.
Now for some practical examples
(a) You're taking a landscape view where you want everything needle-sharp from the foreground all the way to
the background. Easy you say, close the aperture right down to f/1 6-- the snag is that the sky has clouded over
and the light is too poor to use this aperture at a reasonable shutter speed. The remedy -- obtain the maximum
depth-of-field required with the minimum of 'stopping-down (decreasing aperture size). Focus through the
viewfinder on the closest object and note the distance (say 3m) registered against the Index
(10),
then focus on
the most distant part of your subject and note this distance (say 10m) also. Now look at your lens and move the
Focusing Ring
(11)
until both distances appear just between an identical pair of aperture numbers (f/8, in above
example), on the Depth-of-Field scale
(13).
Set the lens to the aperture thus found, use your exposure meter to
determine the correct shutter speed for an exposure at this aperture, then set this speed on the Shutter Speed Dial
(1). Everything between the two distances (3 to 10 meters) shown by the matching aperture numbers (f/8) on the
Depth-of- Field scale
(13)
will appear sharp in the final photograph. (b) If you need absolute maximum depth-
of-field at any given aperture focus on the 'hyper focal distance. This is found by aligning the infinity mark (00)
against the Distance Index
(10).
The distance then found to be aligning with the near limit of depth-of-field for
the aperture required will be the 'hyper focal distance. If the lens is now refocused so that this distance aligns
with the Index
(10)
everything will be sharp from half the distance to infinity.
(c) To obtain a "differential focus" effect, determine the closest and most distant parts of your subject as
described in example (a) above, then refocus the lens so that the distance of the important part of your subject
aligns with, or is near to, either the near or far limits (according to whether you want foreground or background
out-of-focus) on the Depth-of-field scale
(13)
when using a largish aperture, say f/4. Set lens and camera
controls as necessary and you'll be assured of obtaining a picture of high subject impact.
