There are tons of things to consider when choosing a new scope and it can be overwhelming.
For some of those considerations, there’s a clear better option. Obviously you want clearer optics and superior durability. However, for some of them, one option isn’t necessarily better than the other.
One such thing is the focal plane. You’ll need to decide if you want a first or second focal plane scope and there’s no “right” answer. Ultimately, it just comes down to personal preference.
However, to know which you prefer, you have to know the difference between the two.
To help you out with that, we’ve put together this guide. We’ll compare first and second focal plane scopes to help you understand which one is right with you.
So let’s dive right in.
Table Of Contents
What Is A First Focal Plane Scope?
To understand focal planes, first we need to talk about the erector system. The erector system is housed in the main tube of the scope and contains the magnification lenses and the reticle.
In a first focal plane scope, or FFP scope, the reticle is positioned in front of the magnification lenses, towards the objective lens. For this reason, the first focal plane is also often called the front focal plane.
Anything in front of the magnification lens is magnified, including the reticle. This causes the reticle to appear to grow and shrink proportionally with your target.
The reticle in a first focal plane scope can be referred to as a first focal plane reticle or FFP reticle.
What Is A Second Focal Plane Scope?
In contrast, in a second focal plane scope, or SFP scope, the reticle is positioned behind the magnification lenses within the erector system, towards the optical lens. Because of this, the second focal plane is often also referred to as the rear focal plane.
Because the reticle is behind the magnification lens, it’s not magnified. It, therefore, stays the same size regardless of the magnification power setting. Even as the target appears to grow larger or smaller, the reticle maintains the same size.
Like with the first focal plane, the reticle on a second focal plane scope can be referred to as a second focal plane reticle or SFP reticle.
What Are The Pros of the First Focal Plane?
The primary advantage of first focal plane reticles is that they maintain proportions across magnification settings.
The reticle’s subtensions stay consistent regardless of magnification. This means you can easily use the hash marks to make corrections for bullet drop and windage regardless of magnification level. It also allows you to determine the distance of an object while using any magnification setting.
On the other hand, first focal plane reticles can look small and thin at low magnification strengths. This makes the reticle hard to see, especially when using low power in low light conditions. To combat this, many first focal plane scopes have illuminated reticles to improve low light visibility.
At the other end of the spectrum, first focal plane reticles can also look overly thick at high magnification strengths. This can cause them to obscure the target and make the hash marks more difficult to use.
It can also make part of the reticle hidden outside of the scope picture. Some shooters find this irritating or disconcerting. Unfortunately, neither of these problems can be helped by anything as simple as adding illumination.
One last advantage is that some scopes have the turrets and reticles matched. This means that a fixed number of clicks (usually 10) perfectly coordinates with the spacing of the hash marks on the reticle.
In other words, the real world distance represented by 10 clicks is equal to that represented by the distance between two hash marks on the reticle.
First focal plane reticles ensure that the turrets and reticles continue to match on all magnification settings.
What Are The Pros of the Second Focal Plane?
To address the advantages of second focal plane reticles, we need to look at the disadvantages of first focal plane reticles.
At higher magnifications, first focal plane reticles can be too thick and obscure the target. At low magnifications, it can be too small and thin, so it’s hard to see.
A second focal plane reticle, however, always stays the same size and thickness. This is true even as you change magnification strength. Sure, first focal plane reticles may make calculations easier. However, calculations are impossible if you can’t clearly see the aiming points in the first place.
In addition, second focal plane scopes tend to be much cheaper than first focal plane scopes. If you’re on a budget, the lower price point can be a huge advantage of second focal plane scopes.
What Are The Main Differences between First Vs Second Focal Planes?
We’ve talked quite a bit about the main difference between first and second focal plane reticles: proportionality.
I’m not going to bother rehashing it here. Instead, I want to go over a couple of other differences that are a result of the difference in proportionality.
Most Common Reticle Types
Because they maintain proportionality, first focal plane scopes are best when using a mil-dot or BDC reticle. Otherwise, the milliradians or MOAs will only be accurate at one of the scope’s magnification settings. On the vast majority of scopes, they’ll be accurate at the high magnification setting.
It will, therefore, take more work to properly calculate holdover points at lower powers. This is because you’ll have to factor in the difference in magnification strength as well.
The second focal plane is just fine for reticles without ballistic markings, such as crosshairs or duplex reticles.
However, that doesn’t mean that you’ll never see a second focal plane scope with a mil-dot reticle or a first focal plane scope with a duplex reticle. In fact, both are quite common.
There’s no special disadvantage to having a duplex or crosshair reticle in the first focal plane. A second focal plane mil-dot or BDC reticle simply requires more complicated calculations unless you’re using the highest magnification.
First focal plane reticles are good for long-range shooting because subtensions stay the same across the magnification range.
If you’re only shooting close range, a second focal plane reticle may be better. First, because ballistic corrections are less necessary at close range. Second, because second focal plane reticles are more visible at lower magnifications.
Similarly, second focal plane reticles can be good for target shooters. When target shooting, you generally already know the distance to your target. Because of that, being able to calculate range is less important.
As for ballistic correction, it is possible to make those calculations with a duplex reticle. It’s just a little trickier and not quite as accurate.
Traditional hunting scopes tend to be in the second focal plane since hunting doesn’t usually require long range shots.
First focal plane hunting scopes are becoming more popular, though. First focal plane hunting scopes are especially popular for long-range hunting in more open environments.
Tactical scopes tend to be in the first focal plane for easy range estimation.