Home Forums Hunting & Shooting Hunting Optics how was any of this possible without FFP?!?

As is the case with any other piece of gear, every design decision always involves accepting tradeoffs. There's a place for both SFP and FFP and valid arguments for both. One thing that is often cited as a FFP disadvantage is the old "reticle is worthless at low power" anecdote. Sometimes that's true, but not always. It depends entirely on the design of the reticle in question and the zoom ratio of the optic in question. I have several FFP scopes with reticles that I promise you are just as visible at 3X as any SFP hunting duplex reticle, even with illumination off, but certainly more so with illumination on. It all depends on how thick features like the outer bars on the reticle are, how far these bars extend toward the reticle's center, and other reticle features expressly designed to work at both extreme ends of the zoom range. At the same time, these same reticles have thin enough inner bars for extremely precise aiming at the highest magnification. Again, its all a matter of good design.

Another advantage to FFP that is almost never discussed is the fact that it is far more likely to maintain POI when magnification is changed. The reason for this is because in a SFP scope, the reticle is located at the front of the zoom tube & erector, and can be shifted off center with power changes by sliding parts adjacent to it. The higher the magnification selected, the more offset error comes into play if everything isn't perfectly aligned and centered. It requires much tighter mating tolerances of parts to prevent zero shift in a SFP scope. This isn't an issue in most well-designed, quality scopes, but it is possible nonetheless. It isn't possible at all in a FFP scope because the reticle in a FFP scope is located on the objective lens group side of the erector assy, independent of the zoom assy. The target image and the reticle are in the same optical plane, always locked together. In short, a SFP scope may shift POI some with power change, but a FFP scope mechanically cannot, at least not from this cause.