Have you been shopping for a precision rifle optic, or really any adjustable magnification optic lately? If so, you’ve definitely come up against the phrase First Focal Plane (FFP) or Second Focal Plane (SFP). The FFP vs SFP debate is a real rager, much like the venerable 9mm versus anything that starts with a 4.
Well, that’s not entirely true. Compared to several years back when I first started getting interested in precision rifles, it seems like the debate amongst the message board crowds is more or less settled and first focal plane optics won the day.
The main holdouts favoring second focal plane optics seem to be old-timers who learned to do things a certain way and just find it comfortable. But that doesn’t mean they’re entirely wrong.
In general, I think FFP optics provide the most versatility, especially now that we’ve got some truly fantastic magnification ranges and reticle designs for tactical rifles. But whether the FFP or SFP configuration is best for you depends on a lot of other factors, which we’re going to touch one here.
As usual, I’m going to do a bit of history and explanation along the way. So if you just want the skinny, here you go.
Bottom Line Up Front (BLUF): FFP vs SFP Scopes
Current “wisdom” is that you should buy an FFP rifle scope and be done with it. I’ll agree with that in most circumstances, but not all. The truth is that the question of FFP or SFP is a matter of prioritization relative to other characteristics. Some use cases, such as precision rifle competition, lend themselves much more to FFP optics for speed and simplicity reasons.
In other circumstances, such as closer-ranged defensive shooting, it’s a “nice to have” but is secondary to other important things like durability and illumination.
FFP rifle scopes are most useful when you regularly utilize holdovers or you need to spot impacts/misses at unknown distances for corrections. This is particularly good for precision reticles with lots of reference points.
I’m not going to say that SFP scopes are “best” for anything, but the focal plane of the reticle is less important when you’re primary emphasis is either on a speedy sight picture or you have a lot of time to dial both elevation and windage with the turrets. The use cases that come to mind here are either relatively close defensive shooting where holdovers don’t matter or precision shooting without a strict time component.
If you’re doing more of the latter, then things like illumination, tracking accuracy/repeatability, and durability should be more important to you than the focal plane.
So what does First Focal Plane Mean?
The above video does a great job laying out the difference. But if you aren’t in a good spot to watch it, let’s cover the basics first.
When we talk about first focal plane versus second focal plane, we’re really talking about the position of the reticle relative to the scope’s magnification erector assembly. The erector is where the real magnification work of a scope happens. With an FFP riflescope, the reticle is in front of the assembly. This means that the optic magnifies the reticle along with the image at the same time.
As you move the scope through its magnification range, the reticle grows and shrinks with it. In practice, this means that the reticle’s subtensions always remain accurate. Put simply, something measured at 1 MRAD at 4x is also 1 MRAD at 24X magnification.
These photos show a first focal plane reticle as it zooms through its range. This one is from my review of the Meopta Optika6 5-3-x56. Notice how the reticle increases in size as the magnifiation increases.
So that means the second focal plane…
If the first focal plane is in front of the erector assembly, then you’ve probably guessed that the second focal plane is behind it. When you place the reticle here, it remains the same size no matter what magnification setting you place the scope on.
If the reticle within a second focal plane riflescope has measurement markings, such as MRAD or MOA, then they are only accurate at a specific magnification setting. That setting depends on the manufacturer and usually depends on the magnification range.
For example, I had an older Vortex Viper 6-20×44 with a classic mil dot reticle. Vortex indicated that they calibrated the mil dots for use at 14x magnification. Other optics may have the calibration set for the highest magnification, especially if it peaks at 10x or something relatively low.
These photos show a look through my Trijicon TR-24 1-4x scope (it’s the only SFP optic I have on hand). Notice how the reticle stays the same size in both photos despite the increasing magnification.
This isn’t to say SFP scopes aren’t useful at magnification other than what they’re calibrated for. It just requires you to take some extra steps.
If you reduce the magnification to half of the calibrated point, then the amount of area covered by the reticle doubles. If you reduce the magnification to a quarter, then the amount of area quadruples.
The same applies as you increase the magnification beyond the calibrated setting.
This is probably easier to talk through an example. Let’s use my old 6-20×44 PA with mil dots calibrated for 14x.
If I reduce the magnification to 7x, then the distance between each dot is 2 MRAD. That’s easy because 7 divided by 14 is .5. Dividing 1 by .5 gives me 2.
Things get tricky when you start using other magnification settings. For example, setting the scope to 10x leaves me with an odd result of 0.714, meaning that my distance from dot to dot is now 1.4 MRAD.
If I increase the magnification beyond the calibration point, it works in reverse. Instead of the dots covering more space, they cover less. Let’s set the magnification to 17.5, which is 1/4 beyond the set point. Here, the space between each dot becomes .8 MRAD.
SFP Math Easy Button
Unless you plan on bringing a calculator into the field, it’s not terribly practical to do reticle math in your head like this. So most shooters using SFP optics stick to using some easily divisible settings on the magnification ring.
For example, if a SFP scope maxes out at 24x and the manufacturer calibrates the reticle for 24x, then the math for 12x and 6x is pretty simple at 1/2 and 1/4.
These are a couple more “through the scope” photos courtesy of ILya over at Optics Thoughts. This is a SFP Delta Stryker 1-6x optic. The hash marks are 1 MRAD each, but are only accurate at 6x. Notice, again, how the reticle stays the same size no matter the magnification, it’s only the target that changes size.
FFP vs SFP Use Cases
With the technical stuff out of the way, let’s get down to real-world use cases. All things being equal, a well-designed FFP optic provides more versatility and capability. However, you’re going to pay for it. As my recent interview with ILya from Optics Thoughts mentioned, everything with optics is a compromise. Given a choice between a mediocre FFP scope or a well-made SFP optic at a similar price point, you might be better off with the latter.
So what circumstances are those? When would you be just fine with a second focal plane scope?
Well, I think that comes down to how you’re actually using the rifle.
Competition vs Tactical Shooting vs Hunting
First focal plane optics are most useful when you need to utilize holdovers at distance or when you need to spot misses for quick corrections. For most people, this situation means you’re shooting in a match.
In fact, there are several match directors out there in the Precision Rifle Series (PRS) setting up stages where you aren’t even allowed to dial your scope’s turrets. They’re forcing you into holdovers. That’s a perfect environment for both FFP and some kind of “tree” reticle.
The further away you get from that scenario, the less important FFP becomes.
Let’s consider tactical or defensive situations. History shows that actual gunfighting, even in war, takes place short to medium ranges. Most of it within 100 yards, with anything beyond 300 yards a rarity. At that distance, the 5.56 drops just a touch more than 1 MRAD. That’s small enough that you could essentially “hold center mass and fire.”
Of course, we’re talking high-speed relatively close range shooting and not precision here. That’s the reason that the reticle in my TR24 pictured above is designed the way it is.
In these kinds of conditions, the magnification of a scope is more about target identification than precision. You don’t need a first focal plane reticle to assist with that.
But What About Milling Targets?
One of the classic arguments for a FFP optic is that it makes “milling” a target much easier. By milling, I mean using the reference marks of the reticle to estimate the distance to a target. It’s one of those classic precision shooting skills and really nifty to impress your friends with.
However, how practical is it for the real world? Most serious shooters with a need to determine the distance to a target will bring along a laser rangefinder. At longer distances, the margin of error is too great. No hunter would leave that first shot to chance or human error when a small handheld device takes the guesswork out.
For competitions, match directors don’t have time to let shooters range the targets because they have to get people through the stages quickly. So it is common to provide the distances to each target ahead of time.
I’m not saying that milling is useless. But, I wouldn’t use it as justification for a first focal plane scope. Let’s stick to the really useful aspects, such as holdovers and shot corrections.
FFP vs SFP for Snipers
Aside from competition, military and police snipers also have a use for FFP scopes when there needs to be a rapid and precise follow-up shot. That could mean the shooter is spotting their own miss, or it could mean they are working with a spotter calling a correction.
In either case, the shooter must be able to quickly implement the correction and get the second shot off. First focal plane optics make that significantly easier.
FFP vs SFP for hunting is a bit of a wash. I put it squarely in the “nice to have” box because most hunters I know don’t plan on taking shots at very long due to ethics concerns and uncontrollable variables like the wind. Once they fire that first shot, the chances of getting a quick follow-up after a miss are very slim.
Again, I’m not saying that you shouldn’t get an FFP optic if your primary use case is hunting, but it should be secondary to useful magnification, low weight, good resolution, and durability against heavier hunting cartridges.
So let’s get to the bottom line. When it comes to comparing FFP vs SFP optics, you have to think about what you really need it to do. If money was no object, then I would say to go ahead and get the FFP scope and call it a day.
But funds being limited in the real world, it’s best to think about the most important characteristics first. It’s better to get a basic scope that does the important things really well, such as resolution and tracking, rather than a similarly-priced optic packed full of gadgetry.
The only time a first focal plane scope ever becomes a serious factor is for competitive and mid to long-tactical shooting. For everything else it is a “nice to have,” secondary to spending your money on optics that execute the basics well.