Camera Shutter Speeds – Important Notes (Part 1)

Most photographers know that the shutter speed on a camera can regulate exposure, but it also can be used as a creative tool to add interest to images. It can do many things in order to convey messages through photographs.  Shutter speed can be used to give the audience a feeling of motion, frozen action, smooth water and isolate single subjects in addition to its other abilities.  This article is meant to instruct as well as inspire photographers to use their talent and imagination in tandem with the shutter speed on their camera to further their art and stimulate creativity.

Shutter speed is defined as the duration of time a camera’s shutter is open, letting in light from the moment the shutter opens until the moment it closes.  As a reminder, the shutter of the camera works like blinds on a window; it lets in light when it is open, and then when it closes the light is shut out and exposure ends.  If a photograph includes moving objects, the shutter speed can make the objects appear frozen or appear blurred.  One cautionary note:  the shutter speed cannot be changed without changing other settings on the camera without compromising the quality and exposure of the photograph.

Some helpful information regarding shutter speed, camera settings and side effects:    

The combinations of ISO speed and aperture (f-number) allow for a broad spectrum of useable shutter speeds.  Despite the combination chosen, rules dictate that an increase in light allows for faster maximum shutter speeds, while decreased light enables slower minimum shutter speeds.  The spectrum of shutter speeds differs with the camera used for capturing the image as well.  SLR cameras have a broad range of speeds (10,000X), while compact cameras have a more narrow range (500X).

Keep in mind that for short exposure times, the shutter speed conveys the amount of time different parts of the light sensor are exposed to light, instead of conveying the time over which the entire sensor is exposed to light for longer exposure times. 

There are many different ways the photographer can accomplish the feeling of motion in an image, using shutter speed as the creative device.  For example, the subject can be blurred, isolated sharp or rendered a mere streak across the photograph, all depending on the shutter speed.  The difficult part of using shutter speed is achieving the right amount of blur to convey an intended message.  As with most creative devices, do not try to judge the appropriate amount of blur from the camera screen, as the image can look completely different on a larger computer monitor.  That being said, do not delete photographs from the camera before judging their integrity on a larger screen.  It is just as easy to delete the image from the computer, after it is seen in its larger form.

For any shutter speed, there are three traits that influence the blurred appearance of the subject.  The following traits will help a photographer determine what shutter speed will most accurately achieve the correct amount of blur in an image: 

SPEED

Faster moving subjects will cause more blur in an image.  It seems like an obvious observation, but it is important nonetheless.

MOTION DIRECTION

The most blurred subjects will be those moving horizontally across the frame.  Subjects that are moving away from the camera or toward the camera will be less blurry.  It might seem counterintuitive that subjects moving at the same rate will appear differently in a photograph, but this is a hard and fast rule.

MAGNIFICATION

This is the trait that the photographer has the most control over, since it is the combination of focal length and subject distance.  It means that a subject that takes up a greater portion of the frame will appear the most blurry in an image.  Blurriness can also be exacerbated by camera shake that can appear worse in longer focal lengths.

As with most things in life, practice and experimentation are the keys to becoming more adept at using shutter speed as a creative tool.  Water is a common subject to use while attempting to develop an intuition for correct shutter speeds under different circumstances.  Generally, photographers want water to appear in motion for their photographs, so it is a good subject to use when experimenting with different shutter speeds.  

Slow shutter speeds can isolate a subject and freeze it while the surrounding environment appears to be a moving blur.  This is used to emphasize a single object among many moving objects and can result in interesting photographs.

In an opposite scenario, motion can be conveyed by having the subject in focus while the surrounding area in the frame is completely blurred.  In order to achieve this, the camera has to move with the subject, known as panning, or is located on the moving subject itself.  

To achieve an interesting effect, take photographs from a moving automobile or an amusement park ride.  Remember, shutter speed is dependant upon speed of motion as well as the stability of the moving object.  Despite what the intentions are for the final product, 1/30 of a second is a good point to start.  After capturing a few images, adjust the camera settings according to what is envisioned for the final product.

When using the panning technique, the camera does not have to move at the same rate as the subject being photographed, but it does have to smoothly follow the subject.  The shutter button should be pressed at the same time, both actions in one smooth continuous motion.

To get a successful panning image, the shutter speed needs to be slow enough to make the background of the photo streak, but fast enough to keep the object of the photograph sharp.  

Again, practice is what it takes to get the hang of this tricky technique, but the end results are worth the time and extra shots.  Longer streaks will make the image more dramatic, and can be achieved by using a tripod with a pan-tilt head or an image-stabilized lens.  

Additionally, successful panning photos require the background to be textured, and not completely out of focus.  The closer the background is, the more streaks will appear for any shutter speed/panning rate.  Another benefit of panning is that it allows the photographer to obtain a sharp image of a subject at slower shutter speeds than would normally be necessary.

Photographing fast-moving objects is challenging. The trick is to anticipate when the subject will be in the desired position and press the shutter a moment before.  This is because the human reaction time is slower than shutter speeds shorter than 1/5 of a second.  

If the photographer reacts and presses the shutter button, the moment desired to be captured will be missed. Adding to human limitations, most cameras have a delay from the time the shutter button is pressed and when the exposure actually begins. This phenomenon is known as shutter lag. This lag can be anywhere from 1/10 or 1/20 of a second in professional grade digital cameras, to as much as ½ to one second in compact digital cameras.

Keep in mind this shutter lag does not include the extra ½ to 1 second the camera takes to auto focus.  The best remedy this problem is to pre-focus the intended subject and surroundings of the photographs to decrease shutter lag as much as possible.