There are several things to consider when choosing a new riflescope. Magnification is an obvious choice, and we covered MOA and MRad reticles in a recent article. Another feature to think about – and one that often confuses new hunters – is the “focal plane” of the scope.
Oscilloscopes can be either “first focal plane” (FFP) or “second focal plane” (SFP). These terms indicate whether the reticle is placed in front or behind the scope mounting system. The mounting system is the mechanical system that creates the magnification and houses the reticle, but we’ll save a technical description of the scope’s construction for another day.
For our purposes, here is the key information you need to know.
- In an FFP scope, the reticle grows and shrinks along with the magnification.
- In an SFP scope, the reticle remains the same size regardless of the magnification level.
Second Focal Plane Scopes
Since the size of the reticle does not change in SFP scopes, the reticle hash marks that indicate hold for bullet drop only work at the highest magnification power. They could theoretically be set to operate at any magnification, but oscilloscope manufacturers usually set them to operate at maximum magnification. So if your SFP scope is 3-9x and your scope manual says to hold at the first hash mark at 200 meters, you need to zoom up to 9x for this hold to work. The same goes for wind marks, if any. Composing the scope turrets to compensate for bullet drop will still work at every magnification. Only the retainer marks on the reticle are affected by the SFP design.
The reticle on a second focal plane scope does not change size. (Note: image is not to scale)
First Focal Plane Scopes
In an FFP scope, the reticle hash marks work at every magnification because the reticle grows and shrinks with the magnification setting. This 200 yard Bullet Drop Compensation (BDC) mark will work at 3x and 9x, although the reticle will look much smaller at the lowest magnification setting.
The reticle on a first focal plane scope changes size depending on the level of magnification. (Note: image is not to scale)
What is better?
As mom always said about your siblings, SFP is not better than FFP (and vice versa). It’s just different. Unlike mom, I really mean it.
Ryan Muckenhirn from Vortex told me that your choice depends on the terrain of your hunting ground. Muckenhirn is a sales and product specialist, and he regularly explains to customers the pros and cons of each choice.
“If a customer calls and says, ‘Which scope should I use?’ I ask them to tell me about the pitch,” he said.
FFP scopes are all the rage in the world of tactical long-range shooting, and it’s easy to see why. In some long-range shooting scenarios, you might not want to scale this Hubble telescope up to 25x. If there is a lot of candling on a hot day, for example, a lower magnification can reduce this distortion. Transitioning between targets is also generally easier at lower magnifications. In these scenarios it is useful to have a BDC reticle that works on 18x or 12x.
That’s why Muckenhirn has no problem recommending an FFP scope to a hunter considering targeting open country animals. The reticle will still be easy to see at higher magnifications, and the BDC marks will work all the way up the magnification scale.
“Do you hunt Coues deer in Arizona?” If so, go for a first focal plane, turn it on and enjoy the extra magnification and full reticle,” he said.
However, if there’s a chance you’ll be tracking animals in woods or other low-light conditions, Muckenhirn recommends an SFP scope. The reticle on an SFP scope will remain large and visible even at lower magnification levels which facilitate greater light entry. This will allow you to keep your scope at 3x or 5x and still see the deer crosshairs at 100 or 150 yards. BDC marks won’t work well at this lower magnification, but you won’t need to use them at these distances anyway.
Muckenhirn found himself in exactly this scenario last year. His 4.5x-22x FFP scope was excellent in the big country of Wyoming, but as soon as he entered the woods he had trouble seeing his reticle and preparing for a snapshot with lower magnification settings .
“If I could go back in time, I would have chosen a second focal plane riflescope,” he said.
Muckenhirn likes SFP scopes, especially in the higher magnification category of 15x to 18x. Hunting applications don’t often require huge magnification, and 15x is sufficient to bring most shooters and centerfire cartridges to terminal levels. This will let you see that pronghorn at 600 yards, and the BDC reticle will dial in at full power.
There’s a reason most scopes designed for hunting are SFPs. Hunting is unpredictable and you never know when you’ll need to make a close range shot in less than ideal lighting. An SFP range is far superior in this scenario, but every hunt is different. My advice? Look through the SFP and FFP oscilloscopes in store, or better yet, recruit a friend who will let you see the difference from a distance. With real hands-on experience, you might find the choice easier than you think.