Understanding Shutter-lag in Digital Cameras

By Ziv Haparnas

When using a digital camera to take action photos you will notice that there is a delay between the time you press the shutter button to the time the camera actually takes the photo. In most cases this delay is small enough and not noticeable but when taking action photos, when trying to capture an event that just happened or when trying to capture a moving object this delay can result in a photo that just missed the action. In this article you will better understand what causes the shutter delay and how you can overcome it.

A shutter delay is defined as the time gap between pressing the shutter button to the camera actually capturing the photo. There is no shutter delay in film cameras as in these cameras the shutter button is virtually connected to the shutter itself and holding down the button results in the camera taking a photo immediately. In digital cameras the shutter button is connected to a built-in micro computer and holding down the shutter button initiates a series of events that result in capturing a photo.

When you press the shutter button the camera goes through a series of setup events in order to get all its electronics ready. Only when these events are finished can the camera capture the photo. The time it takes for the camera to complete these events can vary but is usually around one second or so. When taking subsequent photos there is an addition delay as a result of the camera compressing the photo and writing it to the slow flash memory.

Although a circa one second delay does not seem long it can make the difference between capturing an action photo to missing it. Some cameras will also initiate a focus process when the shutter button is held down and will only take the photo when the focus is completed. This can add even more delay.

Although it is impossible to remove the shutter delay in your camera there are few practices that can help avoiding its results. For example many cameras include a burst mode. In burst mode the camera shoots a fast series of photos for as long as the shutter button is held down or until the camera’s memory is full. In this mode the camera writes the photos to a temporary memory which is very fast but small. When the shutter button is released or the memory is full the camera starts the slow process of writing the photos to the flash memory.

Using the burst mode you can shoot fast photos of an action event and then choose the one that best captured the events. The speed and the amount of photos that the burst mode supports vary between cameras. Some high end cameras can take as much as ten photos over the course of one second.

Another delay that is a result of the digital camera technology is the Initial Delay. Most cameras will enter into a standby mode if not used for a certain amount of time. This time can vary but it’s usually in the few minutes range. When the camera goes into standby mode it turns off most of its electronics in order to save power. Usually pressing the shutter button will restart the camera but such a restart process is long and can take a few seconds. The result is a longer delay when taking a photo after the camera was idle for some time. In order to avoid this you would have to make sure that your camera is turned on and does not go into standby mode when taking action photos. Some cameras allow you to disable the automatic standby feature through a menu option. If your camera does not allow that you can keep it on by pressing the shutter button half way down every now and then. The downside of leaving the camera on all the time is wasting battery power. In order to maximize battery life in such scenarios you can disable the camera’s LCD screen which consumes a lot of energy and use the view finder instead.

Another way to minimize the shutter delay is to avoid the automatic focus process which usually starts when the shutter button is held down. One way to do that is to hold the shutter button half way down. In most cameras the result will be a one time focus process and then a focus lock. The camera will stay in focus and when the shutter is fully pressed it will take a photo without re-focusing. Another option is to put the camera in manual focus.

It takes practice to get to know your camera and to get a feeling of the delays it introduces. Although there is no way to completely get rid of the delays you can master overcoming them by practicing taking action photos. New high end professional cameras have a very short delay and as the electronics improve cameras will eliminate the shutter delay altogether.