Reticles and FFP

[CMOS]

Let's say you have a front focal plane scope. The reticle is specified to have a line thicknes of 0.02 MOA at 25X. When you zoom out to 5X, that's going to be 5X less magnification, meaning that the line thickness is now .004 MOA, right?

I'm just thinking that with an FFP scope that starts with fine lines, it might be really hard to see the reticle when you back out the magnification.

Is that a real issue?

 

[K Train]

With a FFP it will be the same.

Mine @ 3.5 vs 15x is a huge difference in reticle size but it stays the same size in relation to the target as I zoom in/out. In the scope it can be perceived as bigger/smaller but in reality it stays the same size in relation to the target

 

[CMOS]

This article at the Premier Reticles site (http://www.premierreticles.com/pdfs/2009-HowToFFP-SFP.pdf) seems to say that the FFP reticle will appear smaller and have thinner lines at low magnification.

 

[K Train]

This article at the Premier Reticles site (http://www.premierreticles.com/pdfs/2009-HowToFFP-SFP.pdf) seems to say that the FFP reticle will appear smaller and have thinner lines at low magnification.

"appears"

The reticle is tiny at low magnification, no doubt, but it stays the same, however, I can only speak for nightforce on this one.

 

[E.Shell]

"appears"

The reticle is tiny at low magnification, no doubt, but it stays the same, however, I can only speak for nightforce on this one.

This is true of all FFP scopes, and the reticle is maintained at the same size relative to the image.

This is the only perception the user really has on the reticle; relative size: How does it look compared to the image?

When we reduce magnification in a FFP scope, our image gets smaller, and our reticle gets smaller with it. If your reticle subtends .02 MOA at 20x, it will STILL subtend .02 MOA at 5x. We keep our reticle:target relationship the same, so the reticle size actually tells us something if we need it to.

A second focal plane scope will maintain the same reticle appearance throughout our zoom range, so we lose our calibrated relationship to our target image. At lower power, it subtends a larger area of the target and will not be at the correct dimension at any magnification except where it is calibrated.

As we reduce magnification, the image becomes smaller behind the reticle. At a random magnification, the reticle will have a random value, and it will only be correct at a certain magnification setting. If we have a SFP scope with a .02 MOA reticle at 20x, it will be .01 MOA at 10x.

The importance of a FFP scope is that the reticle DOES stay the same size, which makes sense, since if the image gets smaller, so does the reticle, and we always keep our reticle relationship to the target image. This is important when using the reticle graduations for holdovers, leading moving targets or to range unknown distances.

The advantage of a SFP is that the reticle will always be clearly visible, and in low visibility conditions, if we reduce magnification, the reticle stays large enough to stand out well.

Advantages and disadvantages pertain to the actual scope usage, but one is not necessarily better than the other in all aspects.

 

[Biggfoot44]

Non issue with fixed power scopes.

 

[E.Shell]

Non issue with fixed power scopes.

True.

 

[Idempotent]

Gasoline isn't an issue with horse-drawn carriages either

 

[JamesBailey]

I have this reticle on my 3.2-17x FFP scope and I have no problem seeing the lines at 3.2x.

Of course, I have a similar reticle on a 1.8-10x FFP scope and it is a bit tough to see the lines at 1.8x. I turn on the illumination and makes it much easier to see the crosshairs, although not the MOA hash marks.

As Ed said, if you are going to be miling and holding in anything but the max power, a FFP scope is the way to go. If speed is major concern, SFP.

 

[Biggfoot44]

That was my luddite voice in the wind that variables are rarely needed, and that fixed power scopes have multiple advantages.
I spent decades debating the wisdom of scopes at all with #1 shooting/ handloading partner who figured if he could shoot metalic sights in competion @ 600, what was need for a scope. By 40s he saw the occasional need for a 4x .

 

[E.Shell]

That was my luddite voice in the wind that variables are rarely needed, and that fixed power scopes have multiple advantages.

<grin> I hunted with a fixed 6x for about 10 years...

The problem with fixed scopes is mainly in mixed applications. Just one example is a long range rifle that occasionally gets close use, like a "beanfield rifle" on a foggy day.

I spent decades debating the wisdom of scopes at all with #1 shooting/ handloading partner who figured if he could shoot metalic sights in competion @ 600, what was need for a scope. By 40s he saw the occasional need for a 4x .

I love the way these guys say they shoot iron sights at "x distance" with no trouble. This is only because they are shooting a high contrast, black target against a very light, sometime white background. Give that man a deer standing on the edge of the woods or a groundhog in the edge of partially cut hay, and my money says he cannot even see it over his iron sights.

One big issue with old timers and scopes is that they haphazardly stick a scope on a rifle, half the time jacked up over see-through mounts (which should be both illegal AND immoral), and then can't see through the glass. Their distrust of optics leads them to cripple their outfit, then they proclaim how hard scopes are to use. I guess they are when you approach it like that...

A properly installed scope will be in front of the eye when the rifle is mounted. A scope installed thus can be faster to acquire than irons, and will always be more precise.

 

[Biggfoot44]

While I am not afraid of irons, and prefer them for certain applications, a properly mounted scope is a wonderful thing. It's just the perception that one NEEDS a zillon X in order to hit somthing. An object apearing 9x larger does not make it 9x easier to hit. A riflescope ( or shotgun or pistol) is not a substitute for binoculars or spotting scope. You do not need to count the individual hairs on a deer (etc) ribs to place crosshairs just behind front leg, 1/3 way up ( or shotplacement de jure). The limiting factors are trigger control, steady hold/ position, range estimation, etc. Unless one has severe vision problems 4X will provide adaquate sighting to farther than 99.5+ % of shooters can shoot.

While without seriously boning up , if then, I wouldn't try it, but my Father would connect in front of witnesses at 700+ yds with 4X. And he has nearsighted enough to be kept out of USMC , and barely squeeked thru Navy physical in WWII.

Other than used rigs already setup, I delibertly purchased a variable once. A .257 Wby that I envisioned as a truely dual purpose rig for both typical deer, and varmits at long range.

Most shooters would be better off to trade excess magnafication for improved FOV and eye relief flexability.