Photography Tips – The Shutter Priority Setting: Using The Cameras Tv Setting For Freezing Or Blurring Action

This symbol is on the dials of many cameras-compact & SLR, and is a setting often ignored by photographers unsure about moving beyond the automatic settings of their camera. This article explains what it's about, and helps the photographer to use their camera more creatively for action photography (sports or wildlife) and landscape photography.

Literally speaking, Tv stands for Time Value. In practice, it is referred to as Shutter Priority. This is an important concept in the creative photographer's toolbox.

Understanding How The Camera Calculates Exposure Is Key To Understanding Shutter Priority

The correct exposure for any given image is determined by:

1. the amount of time the light has to get through the hole (the shutter speed)
2. the size of hole the light passes through (the aperture size) on the way to the sensor

(It is of course also affected by the ISO value – a measurement of how quickly the sensor reacts to the incoming light. This is usually determined independently so will be ignored for now).

Shutter Priority (Tv) Means The Speed of The Shutter Is The Key To The Exposure

Choosing the Tv setting tells the camera that the photographer wants to take control of the shutter speed (and hence the amount of time the sensor has to register the incoming light from the image) and the camera should use the shutter speed value set by the photographer when working out the right aperture for a correct exposure.

Taking control of the shutter speed tells the camera that the photographer considers the length of exposure more important than the size of aperture. This means that the photographer doesn't have direct control over the depth of field, but this is less important to the shot than the ability to freeze or intentionally blur the motion of the subject in the image. This is important in a lot of action/sports, wildlife and occasionally landscape, photography.

Shutter Priority Is Important For Freezing The Action In Sports And Landscape Photography

In wildlife, sports and landscape photography, a useful technique is to be able to freeze the action. In sports and wildlife photography this is usually of the sports-person or creature in action, and in landscape this is typically used in scenes involving flowing water or scenes being battered by the wind. A reasonably fast shutter speed is required, and consequently the photographer's chances of success will be improved by shooting in brightly lit conditions – although this is not always an option.

Exact shutter speeds required for freezing the action depend on the action of the subject – a subject moving across the photographer will require a much faster shutter speed to freeze their action than one moving towards the photographer, as for a given viewpoint, their motion is more obvious to the viewer (and the camera!). Typical values used are 1/125 to 1/2000 of a second.

Shutter Priority Is Important For Blurring The Action In Sports And Landscape Photography

In action photography this technique is most likely to be useful for a technique called panning, where the aim is to keep the subject sharp, but allow the background to become motion blurred. This is a great technique for giving the sense of movement and motion of the subject, but requires some practice to gain proficiency.

Typical shutter speeds used in panning are 1/15s to 1/60s second. Much slower, and it is difficult to freeze the motion of the subject ; much faster and either too much is frozen, or more likely the images suffers from that middle ground where the action is neither entirely frozen, nor successfully blurred – it's neither one nor the other and doesn't usually look good.

In landscape photography, setting a slow shutter speed is often useful for blurring the action of moving water – making that lovely silky effect of an ethereal silvery haze where the water has moved during the exposure.

In summary, the Tv Setting gives the photographer creative control over the shutter speed – enabling better use of techniques that freeze or blur the action.