Optics are an important part of your rifle. Whether you’re into target shooting, hunting, airsoft or just the occasional plinking, the long range optics that you use are important to understand to get the most out of your rifle.
There are a number of different features and specifications that are available on rifle optics, particularly scopes. One of the ones you may have come across is the ‘focal plane’. The focal plane describes where the ‘reticule’ sits inside the scope. In this article, we’re looking at the negatives and benefits of the different types of focal plane. If you only shoot with fixed zoom optics, this article won’t affect you as the major factor in first and second focal plane scopes is how the optic behaves under magnification.
Second Focal Plane Optics
Second (2nd) focal plane, often called ‘rear focal plane optics’, are the most common type of rifle optics available on the market, so we’ll cover these first.
The majority of lower end zoom scopes available are second focal plane optics. This means that the reticule that you see when you look through the scope is positioned behind (hence ‘rear’ focal plane) the zooming element; the reticule is between your eye and the magnifying lenses.
What does this mean?
It means that when you zoom your rifle optic, the reticule stays the same size. Whilst what you’re looking at through the scope zooms in closer, the reticule does not change with the image. An inexperienced shooter may not see this as a problem, but it does drastically affect some of the basic functions of the scope.
The reticule does not move and therefore any stadia or mildots (range finding techniques), become incorrect and obsolete at different magnifications. Most shooters compensate for this by predominantly using the optic where it is calibrated (often full magnification), or compensating through experience.
First Focal Plane Optics
First (1st) focal plane optics, often called ‘front focal plane optics’, are often found in the more high end optics.
These are, as you may have guessed, optics that have the reticule placed in front of (hence ‘front’ focal plane) the magnification element. Opposite to how second plane optics perform, this optics mean that the reticule in at the same scale as the target, regardless of the magnification.
This system ensures that the compensation and adjustment units built into the optic are accurate and reliable regardless of the zoom settings.
Which is better?
Which is better depends on your shooting circumstances. Whilst a second focal plane optic lacks the ability to use the compensation marks at all magnification levels, the reticule is always crisp and legible. First focal plane scopes, when used to the extent of the magnification can become harder to read and the reticule can completely occlude the target, not ideal for long range target shooting but perfect for the varying distances of hunting.
A First or Second Focal Plane Scope? Why not both?
A number of manufacturers now offer a hybrid system that offers the best of both worlds. These hybrid or ‘dual focal plane’ optics place the reticule of the scope on the second focal plane; meaning that it is crisp and defined regardless of the magnification, without covering the target too much. All range finding and compensation markings are then placed on the first focal plane, so that they are accurate and consistent at all zoom levels.