Digital cameras have many advantages but they also have some disadvantages and response time is one of them. There are three response times that you should care about: the delay between pressing down the shutter button and shooting a photo, the delay between turning on the camera and shooting a photo and the delay between shooting a photo and shooting a subsequent one. This article explains the causes for these delays and suggests ways to overcome them.
There are three response times or delays that are important to understand and to be aware of when shooting photos. Here is the list with the causes and ideas for how to effectively handle them:
Shutter delay: There is a noticeable delay between pressing the shutter button and capturing a photo. When you press the shutter button the camera goes through a series of setup processes in order to get all its electronics ready. Only when this processing is done can the camera capture a photo. Some cameras will also initiate a focus process when the shutter button is held down and will only take the photo when this focusing process is completed. The delay time varies from camera to camera but is usually less than one second. If you used film cameras before you are probably not used to that delay which did not exist with most film cameras.
Although less than a one second delay sounds very short it can be significant when shooting photos of moving objects such as in sports events. There are a few photo shooting practices that can help in avoiding the delays' results. One way to handle shutter delay is to hold down the shutter half way when taking photos of moving objects. This method can work if the object is in more or less a fixed distance from the camera or is in infinite focus. Holding down the shutter half way locks the focus and forces the camera to do some setup processing work. When you are ready to take your photo press the shutter button all the way down - the result will be a significantly shorter delay as most of the processing work and focus were already done. 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 down it will take a photo without re-focusing. Another option is to put the camera in manual focus.
Subsequent photo delay: This is the delay between taking one photo and when the camera is ready to take a subsequent one. With film cameras this delay was very short as it only involved the camera rolling the film to the next fresh negative. With digital cameras there is processing and housekeeping that needs to be done after each photo is taken. For example the camera has to execute a computational process that compresses the photo (turns the raw pixels into a compressed JPG file) and then it has to store the photo on its memory card (storing files on flash based memory cards is a slow process due to memory technologies used). Another way is using the camera's burst mode (if the camera supports one). 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 volatile 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 memory card. Using burst mode you can shoot fast photos of an action event and then choose the one that best captured the event. The speed and the amount of photos that the burst mode supports vary between cameras. For example some high end cameras can take as much as ten photos over the course of one second.
Initial delay: When you turn the camera on the camera has to run some processing in order to get ready to take photos. The processing includes resetting its electronics, initializing the built-in software, checking the memory card and more. This processing can take a few seconds. The result is that if you want to take a photo when your camera is turned off - you will have to turn it on, wait a few seconds and only then take the photo. In some cases the photo opportunity is gone by that time. Most cameras also enter a standby mode if they are not used for a certain time - usually a few minutes or more. When the camera goes into standby mode it turns off most of its electronics in order to save power. Pressing the shutter button will restart the camera but such a restart process is similar to the process executed when turning the camera on and can take a few seconds. The result is a noticeable delay when taking a photo after the camera was idle for some time. In order to avoid this you would ha ve 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.
New digital cameras have enhanced software and hardware and reduced response times. If you are shooting action photos or are a semi-professional photographer make sure that you check what the delays are (shutter delay, Initial delay and subsequent photo delay) before you buy your next camera. It is a good idea to practice shooting action photos in order to get a better feeling of your cameras delays and responsiveness.
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