What you need to know about focal planes – First focal plane scopes differ from second focal plane scopes, by having their reticle positioned at the opposite end of the magnification lenses. When the magnification is increased, the reticle increases in size along with the image you are looking at. This can often be very useful for long range shooting
FIRST FOCAL PLANE (FFP)
First focal plane optical systems have the reticle positioned toward the turrets of the riflescope, after the magnification system. This means the visible size of the reticle changes when adjusting the riflescope’s magnification; the target image behind the reticle will stay in proportion to the reticle as the magnification is adjusted. As such, the reticle’s aimpoints are correct on all magnification settings. At lower magnifications the visible reticle size will be smaller. At higher magnifications the reticle size will be larger.
The reticle aimpoints (or subtensions) will always remain the same on all magnifications. This is the main advantage of FFP scopes. The benefit of this is that you know, no matter what, your holdover and under aimpoints for longer (and closer) distances will always be correct. You do not need to recalculate your aimpoints after adjusting magnification.
This also gives a great sense of confidence and means you do not need to worry about checking your magnification setting is correct before firing with holdover.
All Hawke FFP riflescopes are currently designed with Mil spaced reticles. When combined with Mil (MRAD) turrets, the click adjustment matches up perfectly. Every 10 clicks equal 1 Mil on the reticle.
As the Mil spacing remains true on all magnifications, the reticle can be easily used for zeroing your riflescope.
E.g. if the point of impact lands 1 Mil space to the right, then the windage turret needs adjusting 10 clicks to the left.
When adjusting magnification, the whole reticle enlarges or reduces in size along with the target you are looking at. This means you do not have an overly large reticle obscuring the view of the target when on low magnification.
Second Focal Plane scopes will always look the same thickness as you look at them. This means that when on lower magnification, the reticle will obscure more of the target you are aiming at.
Range finding is made easier, as it can be done on all magnification settings without need to recalculate. The spacings on the reticle can be used for range finding a target, as the size of the gap between each mark on the reticle is known.
E.g. 1 Mil of spacing is equal to 3.6” at a distance of 100yds. This is true on all magnification settings, so results can be calculated quicker.
The advantage of the reticle changing size with magnification can also prove a disadvantage if being used on low magnifications.
To help overcome this problem, Hawke have ensured all FFP scopes are illuminated, so even if the reticle begins to appear small on lowest magnification setting, you can turn on the illumination and still easily see the aimpoints.
SECOND FOCAL PLANE (SFP)
Second focal plane optical systems have the reticle positioned toward the eyepiece of the riflescope, before the magnification system. As such, the size of the reticle does not change when adjusting the riflescope’s magnification only the object will increase and decrease as the magnification is adjusted. At lower magnifications the object size between the aimpoints will be larger. At higher magnifications the object size between the aimpoints will be smaller. Most SFP reticles are designed with their aimpoints calibrated on a specific magnification.
E.g. the Hawke 10x Mil-Dot reticle is designed to give true Mil spacing when on 10x magnification.
In examples of hunting, SFP reticles are far more popular. A reticle that stays the same size as you see it, means the reticle and aimpoint are always easily visible.
so fast acquisition is made easier.
On FFP scopes, the reticle thickness must be large enough to still be visible on low magnification. This means it will be very thick on high magnification. By comparison, SFP scopes have the same reticle thickness on all magnification.
This generally means the thickness of SFP reticles on high magnification is less than the thickness of FFP reticles on high magnification. The reticle will obscure less of the target and be more useful for target applications like benchrest shooting, or when shooting at a fixed distance.
The center aimpoint (zero) will stay the same on all magnifications, but the target distance of each holdunder and holdover aimpoints above and below the center will change with magnification.
This means having to recalculate the relevant distance of each aimpoint if adjusting between magnifications.
This means you can potentially have a reticle that obscures your view of the target when on lower magnification settings.
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