Chronographs and Precision Cut Archery

Overview

Several of our sight-in methods rely on accurate arrow speed data. The type of chronograph you use determines which sight-in methods are available to you and how precise your results can be.

This guide breaks down the two main types of chronographs, how each is used with Precision Cut Archery, and our recommendations.

Types of Chronographs

There are two main categories of chronographs used in archery today: optical and radar.

Optical Chronographs

Optical chronographs (e.g., ProChrono) use light sensors to measure the speed of an arrow as it passes over the unit. The arrow breaks two light beams separated by a known distance, and the unit calculates speed based on the time between the two breaks.

Pros:

  • Less expensive (typically $100-200)
  • Simple to set up and use

Cons:

  • Can only measure speed at the location of the unit (no downrange measurements)
  • Sensitive to lighting conditions -- direct sunlight, shadows, and indoor fluorescent lighting can all cause inconsistent or inaccurate readings
  • Generally less reliable for archery than radar chronographs

Radar Chronographs

Radar chronographs use Doppler radar to track the projectile in flight. Instead of relying on light sensors, they emit a radar signal and measure the frequency shift as the arrow moves through the beam.

Pros:

  • Some of these units can measure speed at multiple distances downrange in addition to launch speed (e.g. Lab Radar V1)
  • Much more reliable and consistent readings
  • Less affected by lighting and environmental conditions
  • Generally more accurate

Cons:

  • More expensive (typically $300-$600+)

Precision Cut Archery EchoChrono (The Phone Chronograph)

EchoChrono is a new feature in the Precision Cut Archery mobile app that turns your phone into a chronograph.

This uses acoustics and our ballistics engine to determine your arrow's launch speed.

Dedicated chronographs are still more convenient for sure, but if you can't afford one this is a very accurate alternative.

For more information and instructions, see our EchoChrono page.

How Chronographs Are Used with PCA

The type of chronograph you have determines which sight-in methods you can use.

Launch Speed Only

If you only need a launch speed (the speed of your arrow leaving the bow), any chronograph will work -- optical or radar.

This applies to the following sight-in methods:

A less expensive optical chronograph like a ProChrono is perfectly adequate for these methods.

Downrange Speed Measurements

If you want to use the Downrange Speed sight-in method, you'll need a radar chronograph capable of measuring arrow speeds at multiple distances.

This method measures how fast your arrow is traveling at two or more points along its flight path. From this, we can calculate both your arrow's launch speed and its exact drag properties.

Choosing a Radar Chronograph

There are two categories of radar chronographs used in archery: downrange-tracking units that can measure arrow speed at multiple distances in a single shot, and single-point units that measure speed at one location per shot.

Downrange-Tracking Units

These units track the arrow as it flies downrange and can report speeds at multiple distances in a single shot. This makes them very efficient for the Downrange Speed sight-in method.

Lab Radar V1

The original Lab Radar. It gathers speeds at 5x distances in one shot, out to ~65 yards or so. It's a bulkier unit and the interface can be clunky, but it's a proven workhorse for making sight tapes.

For detailed Lab Radar V1 setup instructions, settings, and accessories, see our Lab Radar V1 Tips.

Lab Radar LX

The newer generation Lab Radar. This unit does not track projectiles as far as the Lab Radar V1 does.

We have not tested the LX ourselves at this time.

Single-Point Units

These units measure the arrow's speed at one location per shot. To gather speeds at multiple distances for the Downrange Speed sight-in method, you need to reposition the unit and repeat the process.

Garmin Xero C1 Pro

A compact, user-friendly radar chronograph. It's portable and easy to use for quick launch speed readings. Gathering downrange speed data is more involved since you need to place it downrange and shoot over it.

For detailed Garmin Xero setup instructions, see our Garmin Xero Tips.

Athlon Rangecraft Velocity Pro

A newer radar chronograph option from Athlon. Similar to the Garmin Xero.

No Chronograph at All? (You can still use PCA!)

You can still use Precision Cut Archery without a chronograph! See the What if I don't have a chronograph? section in our sight-in guide for alternatives.