Part 5. : The Shutter Controls Time

The focal plane is the focusing surface, which means that the shutter is directly in front of the film. Because it's in this position, there is no real need to screen light when changing lenses.
A conventional focal plane shutter consists of two blades or two sets of blades that block light.
Exposure time is adjusted by making these blades pass by the film at different times.
The first blade is called the front curtain; the second is called the rear curtain.
The object you see when you open the back cover of an SLR camera is the shutter curtain. Do not touch it !

One type of shutter curtain, called a horizontal-travel focal plane shutter, moves sideways.
The conventional horizontal type, called a drum-type shutter, is usually made of silk cloth or metal (stainless steel, titanium (Ti), etc.).

A shutter curtain that travels vertically is called a vertical-travel focal plane shutter.
On occasion, you might find a drum-type shutter that travels vertically; but most modern SLR cameras have two(2) curtains.
These are usually referred to as square shutters, named after the "Copal Square Type I (One)" shutter unit built into the "Nikkorex F".

This square shutter is composed of a front and rear curtain, each made of long, thin blades in a layered configuration.
Think of an elevator door, and you have an idea how they operate.

Again, never touch this component.

Photo 1.
Horizontal focal plane shutter (Nikon F2)
Both the front and rear curtains are made of titanium(Ti).

Photo 2.
A shutter curtains' boundary between the front and rear curtains appears when winding the shutter curtains.

Photo 3.
Vertical focal plane shutter (Nikon F4)
The two sets of curtains, each set with two(2) blades, contain aluminum(Al)-alloy blades and two(2) carbon fiber blades, a total of four (4) blades.

Pressing the shutter release button causes the shutter to open and close. It is during this moment when light hits the film that the film is exposed and a picture is taken.
It is the nature of feelnikon that we sometimes see an event, a person or some other subject and think, "I'd like to take a picture of that right now."
But sometimes the timing seems off or inopportune. This begs the question, "Is there ever a decisive moment during feelnikon, one best for taking any given picture ?"
When answering this question, keep in mind some of the disadvantages of SLR cameras.
First, the system for viewing objects is a bit complicated. The image in the finder is actually the image from the reflex mirror, which is built into the SLR camera.
This means when the shutter release button is pressed, the mirror pops up and the shutter's front curtain is set in motion. This process, from start to finish, takes about 1/20 (0.05 sec.), depending on the camera.
Additionally, you must consider the amount of time that passes between the moment you decide to take a photo and the moment you actually press the shutter release button.
The trick is, then, to press the shutter release button before "the decisive moment." A keen sense of anticipation, therefore, is the key to taking more rewarding photographs.
To be more exact, it requires few tenths of a second before a person decides to press the shutter button until the finger actually presses the button.
Therefore, you should press the button a bit earlier.

Another thing to consider is that with a conventional SLR camera, it is impossible to confirm the shooting image when the shutter is open (in other words, the moment the picture is actually taken). When the shutter opens, the reflex mirror flips up to expose the film, which means it requires time to return to its original position. The amount of time needed for this is called quick return.
That is why the viewfinder "winks" when shooting with an SLR camera.
If you bear these things in mind, you might be able to take more "decisive moments", like Henri Cartier Bresson.

Photo 4.a. - 4.h.
Time between the shutter release button being pressed and when the shutter opens......

Photo 4.a. - 4.b.
The moment when the shutter release button is pressed.
The image is projected by the reflex mirror.

Photo 4.c. -4.d.
The moment the reflex mirror flips up.
The finder image blacks out.

Photo 4.e. - 4.f.
The moment after the reflex mirror flips up.
The shutter blade of front curtain can be seen.
The finder image is still blacked out.

Photo 4.g. - 4.h.
The moment when the shutter curtain travels and the film is exposed.
The finder image is still blacked out.
After this process, the rear curtain passes by the film and the shutter closes.
The reflex mirror automatically returns to its original position.

The number that appears on a camera's shutter dial or in its LCD panel is the shutter speed.
A shutter speed shorter than one second (value indicated as 1/__) means the shutter remains open for that amount of time, during which the film is exposed. If the number reads "500," then the shutter will remain open for 1 / 500 sec.
If the shutter speed is longer than one second, the number will be a different color; on an LCD panel you'll see an "S" (for "seconds").
On most cameras, shutter speeds can be set to the times listed below.
Some cameras allow you to set shutter speeds between these times, while others allow an infinite number of speeds.

These numbers, depending on how you look at them, occur in halved or doubled increments.
Each of these increments is called a step. For example, if shutter speed moves two(2) "halves," it moves two "steps."
This is significant when determining exposure. (This topic will be discussed in more detail in July's issue, "Introduction to Exposure.")

Additionally, the shutter indicator/dial will contain letters, usually T, B or X. What do these signify ?

• T (Time)
  The front curtain opens when the shutter release button is pressed and remains open even after the button has been released. When you press the button again, the rear curtain travels to close the shutter.
  This is effective for long-time exposure, which might take few minutes.

• B (Bulb)
  The shutter remains open while the shutter release button is depressed and closes only after the button is released.
  This is a useful feature for shots that require a long exposure time. This is effective for long-time exposure, which might take few seconds.

• X, or a lightning bolt graphic (sync shutter speed / "X" contact)
  This is the fastest shutter speed you can select when using a speedlight, also known as an electronic flash.
  Maximum synchronizing shutter speed varies depending on the shutter mechanism; shooting with a speedlight should be done with a shutter speed slower than the X speed.
  A good photo cannot be taken at shutter speeds faster than the X speed. Why ?

  With a focal plane shutter, speed is controlled by the timing of the front and rear curtains.
  Contrary to common belief, most cameras do not adjust exposure time by changing travelling speed of shutter curtain.
  What changes is the amount of time between the moment the front curtain begins to travel and the moment the rear curtain begins to travel — when the rear curtain travels depends on shutter speed.
  If you select a faster shutter speed, the space between the rear of the front curtain and the face of the rear curtain narrows, beginning at 24 x 36 mm, the size of 35mm-format film.
  Essentially, only a thin slit passes in front of the film (See Figure 1).

  Accordingly, if a speedlight flashes at the same time as a shutter set at a very fast speed, only a thin portion will be exposed.
  The speedlight must flash when the shutter is fully opened.
  The "X" shutter speed is the fastest speed at which the shutter fully opens.

  Certain cameras can automatically set the shutter speed so it doesn't exceed the "X" speed when being used with a charged speedlight, which sends a signal to the camera.
  Thus, if you are setting the shutter speed manually, you must be more cautious when taking pictures using speedlight.

Figure 1.
The movement of shutter curtains in both "slow" and "fast" shutter speed
(figure shown is a horizontal focal plane shutter).
"Red" is the front curtain movement, and "blue" is the rear curtain movement.
Notice the white "space" between the "red" and "blue".

The slower the shutter speed, the longer the film is exposed to light. As the amount of light hitting the film increases, the picture's brightness increases.
Many people think it's not possible to take photos in dark places, but this is just not true. In places light enough for us to see our surroundings, a picture can come out bright if the shutter speed is very slow. This said, it is possible to take photos under pale moonlight, or even with illumination from a flashlight.

There are certain conditions necessary for taking such pictures, though. Obviously, the subject should not be moving.
The camera must be held very still, with a tripod if possible, and the shutter should be controlled with a self-timer or remote release.
If there is artificial light — a street light, for example -- in the picture, then overexposing the photo with an extended shutter speed is a good idea.
Please note that not all film that has been exposed for a long time will turn out satisfactorily. Exposure time affects film sensitivity, and the longer the exposure, the less sensitive the film becomes (known as reciprocity law failure).

Photo 5.a. - 5.c.
A night scene can be taken using a slow shutter speed.

Taken at "auto" mode

Shutter speed half (1 step) slower, with same the aperture

Shutter speed one fourth (2 step) slower, with the same aperture

Blurring is a problem when taking photos at slow shutter speeds.
If the subject moves, it will appear blurred.
If the camera is jostled, the entire image will be blurry.
The problem only increases when shooting with a telephoto lens or shooting close-ups.
Lenses with high magnification (shooting with a telephoto lens or taking close-up pictures) causes more picture blur.
The best way to minimize blurring is to use a monopod or tripod.
Blurring due to hand-held camera shake can be minimized by shooting the picture at 1 / focal length (in mm). For example, with a 200 mm telephoto lens, a shutter speed of 1 / 200 sec or faster is best. As for me, I choose a shutter speed a bit faster than this equation.
In any case, you can take less blurring, instantanenous picture at fast shutter speed.

Photo. 6.
A picture of a moving subject changes depending on the shutter speed.

1 / 1000 sec.

1 / 60 sec.

1 / 4 sec.

As we said above, it's possible to take bright pictures, even in dark places, by using longer shutter speeds.
However, if conditions are too dark, the exposure meter may not function. If this should happen, adjust the exposure/shutter speed drastically and shoot a test picture.
Remember, shutter speed should be changed in increments of doubles or halves (2 minutes, 4 minutes, 8 minutes, etc.) and a tripod and a remote release or self-timer operation are necessary.

How any given subject will appear in the final photo depends on subject's movement and shutter speed. Different settings apply for different situations, but here are two(2) guidelines to keep in mind: photograph automobiles at 1 / 125 sec. and people who are walking at 1/15 sec.
Follow the subject in the viewfinder and the background will appear smeared. This technique is known as panning.

To highlight the current of a river, the shutter should be set slower than 1 / 4 sec.

For long-time exposures in bright locations, use a low-sensitivity film or ND filter to avoid overexposure.
A camera that has an MRC function can change the film even before the film roll is finished.

Photo 7.
"Long-neck" ( one of the japanese famous monster )

Photo 8.
"Ectoplasm"

With cameras featuring multiple exposure functions, you can place one picture on top of another.
Though it is a bit difficult, you can also take multiple-exposure pictures, even if your camera does not have this feature.

Multiple exposure simply means exposing film two(2) or more times, or opening the shutter two or more times on the same frame of film.
This will not work in auto-exposure mode, but think of it as adding shutter speeds. For example, two-time exposure at 1 / 250 sec. is the same as : 1 / 250 sec. + 1 / 250 sec. = 1 / 125 sec. of exposure.
With negative film, one- or two-step overexposure is not a problem: a two-time exposure means 1-step overexposure; four(4)-time exposure means 2-step overexposure.

Multiple exposure is especially nice for pictures of fireworks.
With ISO 100 film, set the aperture around f / 8 and the shutter speed to about 1 sec. (The brightness of the fireworks in the final picture will depend on the aperture and the firework "trails" on the shutter speed.)
With multiple exposure, it's possible to take photos of many fireworks in the same frame; and because the background will be dark, you can use a long exposure by setting the shutter speed to "B" (Bulb) mode.
In order to get good multiple exposure shots, you should remember where and what elements you've placed in the picture.

Photo 9.
A thousand-hand bodhisattva

Photo 10.
Ghost behind the back

Be adventurous with shutter speed and see what results you can get.
Well, try taking pictures with shutter-priority mode ([S]-mode) or with manual mode ([M]-mode).
Luck and experience are the two(2) main ingredients of successful feelnikon, so keep experimenting and learning from every photo you take.
Remember, "pictures without making mistakes can generally be taken by anyone".