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First focal plain explained


shawn9914
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Most scopes are Second Focal Plane (SFP), which means that if using a milli dot reticule the distance between two dots when looking at a target will increase as you decrease magnification i.e. a rabbits head might be as wide as 4 millidot as viewed through a scope at say 4x mag, however at 9x mag it may be 8 millidots wide.

 In First Focal Plane the distance between millidots will remain constant regardless of magnification, this means that at higher magnification the whole reticule gets smaller within the field of vision through the scope, it's possible at massively high magnification you might not be able to see individual millidots within the reticule .

Hope that makes some kind of sense!!

Edited by Dasher
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as you zoom the reticle sub tensions stay at 1 moa or mil etc with ffp but with second the ret sub tensions are only true at a certain mag. 

as an example my vortex golden eagle reticle is only accurate 1moa at 40x mag but if the fog comes in and your using the ret turning it down can mean fast math needed.

if it was ffp i could be on 15 or 30 or 60 it would not matter the ret would stay accurate 1moa

only down side to ffp is the ret can be a bit big/thick for small aim points.

 

 

Edited by zx10mike
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25 minutes ago, shawn9914 said:

Thanks again

So with this in mind what should I go for on a rimmy scope 1st or 2nd it seems most scopes are 2nd

 

If you're planning on taking mostly quick free standing shots on rabbits from 15 - 45 yards away then a cheap sfp will be accurate and you won't even tell the difference. If you plan on staking out warrens from 80-150 yards away and have a bolt action rifle (and ammo) with the required accuracy of 10p sized groups at said ranges then a ffp scope will prolly be required. There are many such people on this forum who I'm sure will give good advice if asked. 

I have owned at least a dozen scopes and couldn't tell you whether any were ffp if my life depended on it, being an "aim off" kinda guy I've nonetheless managed to kill magpies at silly range with fac air guns and the odd rabbit and pigeon with a rimmie. 

Edited by Hamster
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51 minutes ago, Hamster said:

If you're planning on taking mostly quick free standing shots on rabbits from 15 - 45 yards away then a cheap sfp will be accurate and you won't even tell the difference. If you plan on staking out warrens from 80-150 yards away and have a bolt action rifle (and ammo) with the required accuracy of 10p sized groups at said ranges then a ffp scope will prolly be required. There are many such people on this forum who I'm sure will give good advice if asked. 

I have owned at least a dozen scopes and couldn't tell you whether any were ffp if my life depended on it, being an "aim off" kinda guy I've nonetheless managed to kill magpies at silly range with fac air guns and the odd rabbit and pigeon with a rimmie. 

Neither First or Second are more or less accurate per se, and NEITHER should lose zero at different magnifications.

Second is far more common and works just fine for most people!

:good:

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In my opinion there is a very good reason the vast majority of scopes are sfp.they are better .

Offer a greater degree of uses and you can adapt them better to your trajectory .dont get a ffp. Scope .

I could give you loads of technical reasons .similar to the explanations above. But without playing with one and seeing for your self their short commings its hard to follow sometimes. 

Stick to sfp. 

 

 

I personally cant see a single advantage to a ffp .Scope. 

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48 minutes ago, Dekers said:

Neither First or Second are more or less accurate per se, and NEITHER should lose zero at different magnifications.

Second is far more common and works just fine for most people!

:good:

You are correct, as I have already admitted as much I don't even know what version the current scopes on my Rem Yellow Jacket and a FX Wildcat are in that regard without checking but these vids make it a little clearer. The telling part is at 1.50 - 2.30 on the first and 4.20 - 4.30 on the second video, in essence it seems if you range the target regularly you ought to go for ffp.

 

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2 hours ago, Ultrastu said:

In my opinion there is a very good reason the vast majority of scopes are sfp.they are better .

Offer a greater degree of uses and you can adapt them better to your trajectory .dont get a ffp. Scope .

I could give you loads of technical reasons .similar to the explanations above. But without playing with one and seeing for your self their short commings its hard to follow sometimes. 

Stick to sfp. 

 

 

I personally cant see a single advantage to a ffp .Scope. 

I was under the impression that FFP was fairly new - therefore a lot of scope designs etc are old and therefore SFP - I don’t see how that makes them better or worse. 

Also FFP are more expensive and a lot of people who shoot competitions are swapping over to FFP. 

I don’t see what you mean that a SFP can be “adapted better to your trajectory” - what does that mean please? 

 

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Ok .take one of  my fave scopes the sfp. Hawke map 6 ret. 

If you shoot a 700 fps pellet and zero it at 30 yds. On 10x mag the scope ret and its dash marks under the main x  will line up beautifully at every 5 yd intervals .making for easy to remember hold over points. So 30. 35 .40 .45 .50 yds 

But if you set the scope at say 14 x mag 

The ret won't line up so well on 5 yds intervals. It will be something more like this. 30 (zero stays the same ) .32.38.42.46 not so easy to remember .

Or lower mag say 8x 

30.37.46.51.59 

Also not so easy to remember .

So 10x mag is spot on and has been tailored to the trajectory of the pellet.

A ffp.scope .might be say 30 yd zero .36.41 .48 .54 .60 

And no amount of different mag is gonna change that..your stuck with those hard to remember  increments. 

 

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2 minutes ago, Ultrastu said:

Ok .take one of  my fave scopes the sfp. Hawke map 6 ret. 

If you shoot a 700 fps pellet and zero it at 30 yds. On 10x mag the scope ret and its dash marks under the main x  will line up beautifully at every 5 yd intervals .making for easy to remember hold over points. So 30. 35 .40 .45 .50 yds 

But if you set the scope at say 14 x mag 

The ret won't line up so well on 5 yds intervals. It will be something more like this. 30 (zero stays the same ) .32.38.42.46 not so easy to remember .

Or lower mag say 8x 

30.37.46.51.59 

Also not so easy to remember .

So 10x mag is spot on and has been tailored to the trajectory of the pellet.

A ffp.scope .might be say 30 yd zero .36.41 .48 .54 .60 

And no amount of different mag is gonna change that..your stuck with those hard to remember  increments. 

 

 

I think the big advantage is - the distance between the dashes is the exact same regardless of the zoom. 

Also not many people using FFP scopes for air rifles - for an air rifle it’s not really worth the cost for the benefit of FFP - I think the scopes come into their own when Shooting fast unknown distances out to say 400-1000 yards. 

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Yeah .maybe 

But a  problem I see is. For a long range shot on a c.f. @. Say 400 yds you wind up the mag to a maximum 20x and the crosshair /ret bars are now so thick that they obscure the target. Making the high mag unuseable .

Personally i like sfp  scopes that work out increment wise on 2 different mag settings. 

Often a hawke sr6 or sr pro .will be correct on 24 x mag and 12 x mag 

One at 5 yd intervals and the lower mag at 10 yd intervals .

Also a 6 x mag can do 20 yd intervals .

Very useful 

1 hour ago, Lloyd90 said:

 

I think the big advantage is - the distance between the dashes is the exact same regardless of the zoom. 

Also not many people using FFP scopes for air rifles - for an air rifle it’s not really worth the cost for the benefit of FFP - I think the scopes come into their own when Shooting fast unknown distances out to say 400-1000 yards. 

I used an airgun to illustrate the difference as pellet drop is most significant .But it applies to any bullet that you wish to shoot out to long range for the cal .

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On scope scopes it can make the reticle too big if shooting small targets - had this issue with a hunting scope in FFP. 

There are however as many different reticles ad there are scopes these days and they don’t all have that issue. 

 

All im saying is there’s a reason a lot of folk are swapping over to ffp - they clearly don’t seem to have the issues you suggest. 

On scope scopes it can make the reticle too big if shooting small targets - had this issue with a hunting scope in FFP. 

There are however as many different reticles ad there are scopes these days and they don’t all have that issue. 

 

All im saying is there’s a reason a lot of folk are swapping over to ffp - they clearly don’t seem to have the issues you suggest. 

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As you say 

The as the magnification of the image increases so does the reticle in the scope increase equally .So if your looking at a deer at 300 yds. And cant pick out the kill zone on its flank cos your on 5 x mag And the ret bars are too thick .then zooming to 20x mag your still gonna have the same issue of not seeing the kill zone .am I not correct .? 

If you can see it ok at 20x mag then you can also at 5x mag. So why all the zooming ?? What's the point. ? Just stick to a nice 10x mag or something and shoot. 

Hey maybe I'm wrong ive not ever bothered to splash out£ 400 on ffp .Just to shoot 1 mag  :oops:

 

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22 minutes ago, Ultrastu said:

As you say 

The as the magnification of the image increases so does the reticle in the scope increase equally .So if your looking at a deer at 300 yds. And cant pick out the kill zone on its flank cos your on 5 x mag And the ret bars are too thick .then zooming to 20x mag your still gonna have the same issue of not seeing the kill zone .am I not correct .? 

If you can see it ok at 20x mag then you can also at 5x mag. So why all the zooming ?? What's the point. ? Just stick to a nice 10x mag or something and shoot. 

Hey maybe I'm wrong ive not ever bothered to splash out£ 400 on ffp .Just to shoot 1 mag  :oops:

 

I think the issue is your assuming all reticle are the same. 

Theres so many different reticles - if trying to hit a very small spot on a high magnification with some reticles they will cover the target. 

There are other reticles that won’t cover the target at all and therefore that one specific point your making won’t apply to many scopes.

if anyone is interested in a FFP scope the best thing to do is try and go and look through the exact one you want and see what it’s going to be like for what you want to use it for ?????? 

Some people will be better off with second focal - use whatever suits you best 

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For a rimfire, there's no good reason that I can think of for anyone to buy a (generally) more expensive FFP.

FFP comes into its own at longer distances and NOT for the reasons of being able to use the reticles for range finding.  They're useful because if you miss and see the bullet splash, however many moa or Mrad increments measured by the ret you're off target, you simply and quickly dial that correction in. That's mostly why they're so popular amongst LR target shooters and long range vermin shooters.

It used to be true that some cheap SFP scopes would have an altered POI with changes to zoom range (and well documented).  These days. most decently made SFP scopes are just fine.

Combined with a well designed ret. FFP all the way for me. for my long range rifles, including the 6.5 which wears a PMii in FFP.  For my stalking scope I'd be more than happy with any SFP and 8 x 56 is amongst my favourites for stalking using a fine 4a ret.  

Don't over think it for a rimfire.  Your ability as a shooter is way more important than fretting over what scope you use on a 22LR or an HMR come to that.

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I own and use both each have their advantages for different applications as Fister said it’s also personal preference.  

Personally at long range with drop and wind age calcs I prefer a FFP scope as it simplifies things in my mind as one MRAD marking is 1 MRAD marking at any mag.  

Stalking I like 2fp and a simple duplex as the ranges are short and I judge my hold over/under etc by the beast, I also use a lot less mag as well.  

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