The Difference Between A Trail Camera’s Shutter Speed and Trigger Speed

Lets be honest, there is a lot of bad information on the internet. I have read countless articles in the last week alone that claim the shutter speed and trigger speed on a trail camera are the same thing. This is just not true, and what is even more concerning is the amount of people who are purchasing trail cameras, on the notion that they are the same thing.

It is tough enough, as a consumer, to decipher between marketing gimmicks, hot sales words, and what actually equates to a great trail camera photo in the end. As always, we will continue to try and give you the best and most up to date information on trail cameras as possible.

So, lets dive into the world of shutter speeds and trigger speeds.

A trigger speed on a trail camera is measured by the amount of time from when the PIR sensor detects heat and motion, to the when the image is captured onto the image sensor. The shutter speed however, is measured in how fast the mechanical shutter on the camera opens and closes.

How Trigger Speed Works

Detection Circuit

Trail cameras on today’s market utilize a detection circuit known as a PIR sensor (Passive Infrared). PIR sensors are used to determine both heat and motion. Everything on this planet has infrared heat that is absorbed from the sun. Animals however produce more heat, and when an animal comes into the detection zone of a camera the PIR sensor recognizes the change in IR from the surrounding area.

The change in IR alone does not trigger the detection circuit. The key to initiating the camera to begin the process of taking a picture, is that the change in IR must also move. This combination of heat and motion, is a safe guard from taking false trigger photos.

Light Meter and Exposure Tables

Once the PIR sensor is activated from heat and motion, the camera then reads the light meter. The light meter is simply an engineered device that reads and determines the amount of light that is available for a photo.

At the very core of photography the ability for a camera to read, channel, and manipulate light, is the most important aspect of having a properly exposed photo.

Through software built in to the back end of your camera, the light meter will relay the information to what is known as the exposure tables.

The exposure tables are predetermined parameters that calculate the best settings the camera should use for ISO, Shutter Speed, and flash intensity. The exposure tables will also relay information to the firmware creating the IR lens to move in front or away from the camera lens, depending on the time of day.

Taking the Photo

Once all of the information from the exposure tables is relayed to the camera, the shutter will open and close. During the time in which the shutter is open the image sensor, which is placed behind the lens of the camera, will collect the image within the frame of view.

How Long A Trigger Speed Takes

The trigger speed of a trail camera is determined from the moment the PIR sensor detects heat and motion, and ends once the image sensor records the photo. All of this includes reading the light meter, which relays the information to the exposure tables, the changes the settings on the camera, activates the flash, and IR lens, and finally takes the photo.

Seems like a lot right? Well the competition of who can have the fastest trigger speeds have brought out the best in speed and technology. For all of the detection, relaying of information, and physical movement of hardware, its funny how a 1 second trigger speed seems like a snail pace, but there are cameras on today’s market that have triggers speeds of less than 1/5 of a second.

Is Faster Trigger Speed Better?

Just having a faster trigger speed, doesn’t equate to having a better quality photo, and it doesn’t mean that you will have less false triggers. Don’t get me wrong, having a faster trigger speed is a great asset, but only when it is combined with with the correct balance between the field of view, and the detection zone.

The field of view is the actual view in which the camera takes the photo. This is created by the angle in the lens, and is often between a 52 and 38 degree angle from the camera.

The detection zone is the angle from the camera, in which the trail camera can detect the change of heat and movement using the PIR sensor.

Fast Trigger Speeds

The balance between the detection zone and the field of view is incredibly important when you add in the trigger speed. If you have a fast trigger speed, typically you would want your detection zone to be at a smaller angle than your field of view. This will ensure that the animal is well within the field of view before the picture is taken.

If the detection zone is larger than the field of view of the camera, with a fast trigger speed, you will often take photos before the animal is in the the picture, resulting in what appears to be the camera taking a photo too quickly.

Slower Trigger Speeds

Often with a slow trigger speed, you will want a detection zone that is larger than the field of view. In these cases what will happen is that as an animal moves into the detection zone, a slower trigger speed will give time for an animal to move into the field of view before the camera actually takes a photo.

With slow triggers speeds the last thing you want is a detection zone that is smaller than the field of view. This will often result in the animal passing through the field of view before the photo is ever taken.

Fast or Slow Trigger Speed

The general consensus is that the ideal trigger speed would be a faster speed around .3 seconds combined with a 42 degree field of view and a 40 degree detection zone. Faster speeds are not always better, but if the manufacturer combines them well with with a favorable size of detection zone and field of view, its the best scenario for capturing photos.

How The Shutter Speed Works

Conventional Cameras

When you begin to deal with shutter speeds, it is easiest to understand by taking a step back and looking at conventional cameras. When a professional photographer takes a photo with their DSLR style camera, you will often hear a clicking noise. That noise is the actual movement of the shutter inside the camera.

What happens with conventional cameras is that when the camera is turned on, the image sensor is always on, and the shutter is always closed. When the photo is actually taken, the shutter will open then close. In the amount of time the shutter is open, the image sensor is able to receive all of the light and images through the lens of the camera and form a picture.

On conventional cameras the opening and closing of the shutter is an actual mechanical movement.

Trail Cameras

Most trail cameras, not all, are different than a conventional camera, in the sense that there is no actual mechanical shutter. What happens with a trail camera, is that the image sensor is off even when the camera is on. When the trail camera goes to take a photo, the software of the camera turns the sensor on and then off again, creating the same affect of allowing light into the sensor as a physical shutter would.

The advantage of this is a two fold solution. The act of physically opening and closing a shutter makes noise, while turning the image sensor on and off is virtually silent. Obviously this is an advantage when dealing wild game who is sensitive to unnatural sounds.

The other thing that this does is, it allows the image sensor to be turned off, saving power and battery life. Conserving battery power is half of the battle for allowing your cameras to soak in the field for long periods of time.

What Shutter Speed Does For A Camera

The speed in which the shutter opens and closes, or in the case for trail cameras, turns the image sensor on and off, has everything to do with controlling light and motion.

The faster the shutter speed, the easier it is for the camera to capture motion. Taking a photo of a sporting event, would require a fast trigger speed, in order to capture an action shot, with no blur. The problem that having a fast shutter speed creates is that it allows very little light into the image sensor.

With trail camera’s having a quick shutter speed is imperative to capturing fast moving animals such as deer, without having motion blur. For night time photos this creates a problem when the amount of light available is limited.

Having a slow shutter speed, consequently will allow more light into the image sensor, but will also have more blur associated with the movement of an animal.

In the end it is important to understand that the shutter speed of a trail camera is only one part of the overall trigger speed. So, don’t be fooled by the bad information on trigger speeds. It pays to be an informed consumer.

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