Second Plane Retical? Or First?

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stargeezer

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As I am exploring scopes at midway, I see many listed as either first plane or second Plane - what is the difference and why one over the other? Sightron SIII looks good, but its listed as second plane and I'm not sure if that's good, or bad. :D

Thanks!
 
Basically, in First plane reticles, the crosshairs will zoom with the image as you adjust magnification, that is they will appear bigger as you increase. The only advantage I see, is that it will allow a quick gauge of range as you zoom, if you're familiar with your scope and it's behavior when increasing magnification, that is the target picture with regard to the cross hair subtension, or width compared to the target - the cross hairs will appear to get fatter as you increase magnification.
In a Second plane reticle (much more common on American scopes) the cross hairs will appear to remain constant as you dial up. This gives what 'feels' like a more precise aiming point, but it's harder to determine range, since the width of the cross hair will cover more width at the target as you dial up.
Again, most scopes you see will have the 2nd plane setup. I don't think most of us are used to the cross hairs growing as we zoom. The availability of Mil-Dot and other simple ranging reticles also have made 1st plane ranging not so much of an advantage I think.
 
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Basically, in First plane reticles, the crosshairs will zoom with the image as you adjust magnification, that is they will appear bigger as you increase. The only advantage I see, is that it will allow a quick gauge of range as you zoom, if you're familiar with your scope and it's behavior when increasing magnification, that is the target picture with regard to the cross hair subtension, or width compared to the target - the cross hairs will appear to get fatter as you increase magnification.
In a Second plane reticle (much more common on American scopes) the cross hairs will appear to remain constant as you dial up. This gives what 'feels' like a more precise aiming point, but it's harder to determine range, since the width of the cross hair will cover more width at the target as you dial up.
Again, most scopes you see will have the 2nd plane setup. I don't think most of us are used to the cross hairs growing as we zoom. The availability of Mil-Dot and other simple ranging reticles also have made 1st plane ranging not so much of an advantage I think.
mildot and other ranging reticals is where FFP scopes excel, there is no need to worry about where on the magnification ring your setting. Follow up shots using the retical as a reference is also made less complicated, see miss, dial scope hit target
 
The problem with FFP reticles is they get really small at 1x. The advantage is the reticle lines are accurate at any power setting.

For the most part, you're only going to be shooting long range when on max power, so the advantage of having a reticle that is accurate at intermediate powers isn't that helpful.
 
I recently bought my first variable power scope - a Nikon P22 with BDC.
Didn't take long to discover a BDC reticle on a 2nd focal plane scope really sucks - who the heck can memorize all those constantly changing BDC values (depending on the power you've selected).
Heck - I'd have to stick a label on the stock or somewhere with all the values per power listed.

My second variable scope was a Bushnell Throw Down PCL.
1st Focal Plane reticle - when on 1x, it functions like a red dot, but dial up the power and the BDC marks come into view, and do not change values no matter the power selected.
 
When I replied I assumed you were asking about 3 gun, which I guess is silly. What are you going to be using it for? I stand by my reply for 3 gun, but for long range shooting the FFP would definitely be ideal.
 
I use a Lee 3 MOA dot on my scopes. A very simple system. On 3 X the dot covers 3 inches at 100 yards. And say I'm looking at a deer and the dot covers the chest top to bottom. That's a 375 -400 yard shot and I know I need to hold over 13 inches. So I crank it up to 9X . The dot still covers 12 inches, and the chest from ce nter to top of back is 6 inches and with bottom of the lee dot held on the top of the back with just a small amount of light I have a 13 MOA hold over. Windage can be done the same way. I have used this system for close to 40 years now.
15 years ago I bought a mil-dot in a Shepard scope. A very quality piece of glass but I liked the Lee dot better. I sold the scope and bought a Leupold 6-18 target scope for the adjustment feature and sent off to Lee to have the Lee Dot put in. That dot has become second nature to me. It's very fast to get the sight picture you want a decide if you ca make the shot. My limit is 400 yards, that's all I'm Capeable of. Fancy mil- dot or bdc didn't advance my capabilities at all
 
When variable power scopes first came out, they were all FFP. The concept of the reticule "growing" with the magnification was considered a problem as precise target aiming became more difficult as at the higher magnification as the aiming point covered more of the target. I believe Redfield is credited with the first 2nd plane variable scope. The military then started using the Redfield as sniper scopes Vietnam as that was considered an advantage.

In precision shooting, usually the finer the cross-hair, the better as it is easier to align on a very precise point. One of the most common target reticules is the 1/8 MOA Dot for that reason. Benchrest shooters, precision target shooters, etc all look for that precision. Although a lot of these scopes are fixed power, all of the variables are 2nd plane.

The FFP scopes have the advantage already mentioned in mildot applications as the ratio remains constant regardless of power. Also the larger reticule is easier to see in reduced light situations vs the fine cross hair. The type of scope you are looking for depends on what type of shooting you want to do. Hope this helps.
 
The availability of Mil-Dot and other simple ranging reticles also have made 1st plane ranging not so much of an advantage I think.
More the opposite, the FFP mildots always stay the same so you can range, holdover, and hold for wind the same at any magnification.

As an example, I bought a Leupold 6.5-20 SFP mildot scope about 16 years ago. The manual didn't say where the mildots were calibrated for magnification wise (usually it's the highest setting). With measuring sticks, I found it is at 12x. How odd; and I can't use easy math (double at half mag, half measures at double mag), if it milled at 20x, then at 10x each dot would be 2 mils. With the 12x setting, I can't go half or double.

Downside, as mentioned a few times above, is a compromise has to be made in reticle thickness so that it isn't overly small at low power and too fat on the highest power. For a pure target scope on KD targets (no ranging required) I'd go SFP for the thinner reticle that stays the same. For a tactical application or for tactical sniper matches, FFP for fast holdovers and consistent ranging at any mag setting.

On the low power variables (1-4, 1-6) they use the FFP in a totally different way (at least SWFA does). On low power there is a circle and cross hair effect for fast shooting. On the high setting, the circle grows so big it goes away and the mildots on the cross hair become usable.
 
The way the mil dots work in several of my FFP scopes is useful.
At lower magnifications, the mildots are too close together to be used. However, I doubt that I will be using low magnification at any range that knowing the distance is needed. Simply speaking, at 3x where the dots are unusable, I doubt that I will be making a 500 yard shot. For that, the 12X will be used and the mildots are quite usable.
You will also find that FFP is a feature on upper end scopes, rarely found on inexpensive optics.

Roger
 
I agree that mil-dots can be too thick to be used at lower magnifications. However, modern reticles using milliradian (MRad) substensions versus actual dots are useable at any mag. And if the scope's turrets are calibrated in milliradians as well, it makes calculating adjustments much easier and much faster.
 
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