Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Long Range Scopes and Other Optics

Long Range Scopes and Other Optics Nightforce Optics


Reply

Explain benefits of front focal plain

 
LinkBack Thread Tools Display Modes
  #1  
Old 11-14-2011, 02:32 PM
Bronze Member
 
Join Date: Nov 2011
Location: Colusa c
Posts: 67
Explain benefits of front focal plain

I am learning so bear with me. What is the benefit of a front focal plane in a scope....
Reply With Quote
  #2  
Old 11-14-2011, 03:07 PM
Gold Member
 
Join Date: Aug 2009
Location: Cheyenne
Posts: 513
Re: Explain benefits of front focal plain

Leupold || FAQs

Basically the reticle "features" work all the time with a FFP scope, but only at one power setting on a SFP scope.
Reply With Quote
  #3  
Old 11-14-2011, 03:18 PM
Silver Member
 
Join Date: Oct 2011
Location: Sun City, Arizona
Posts: 205
Re: Explain benefits of front focal plain

Quote:
Originally Posted by NomadPilot View Post
Leupold || FAQs

Basically the reticle "features" work all the time with a FFP scope, but only at one power setting on a SFP scope.
NomadPilot, really new guy here to this forum, glad i joined as you have answered one question that has always been on my mind. never been too picky about optics until lately since i wish to shoot further out.
you have been a big help, thank you.
Reply With Quote
  #4  
Old 11-14-2011, 04:20 PM
Platinum Member
 
Join Date: Mar 2008
Location: SW Idaho
Posts: 1,160
Re: Explain benefits of front focal plain

The benefit mainly corresponds to any reticle that has multiple hash marks or dots that subtend to varying angles of measurement. It also affects reticles that are designed for a specific ballistic path. This style of reticle includes mil dot or mil hash reticles that may subtend every 1 MIL or 1/2 mil, etc. There are MOA reticles setup the same way but may subtend every 1 MOA or 2 MOA. Also ballistic reticles like the Zeiss Rapid Z or NF's velocity reticle would apply.

On a SFP scope the correct subtention (correct angle of measurement) only occurs at one magnification setting, which is usually the highest. So this means at all other magnifications your ballistic charts regarding hold over/under, MIL/MOA drop etc cannot be directly transferred to the reticle any longer unless a multiplier is applied to the reticle subtentions listed for your scope. This would also affect ones ability to range objects at varying powers or to hold off for windage at various powers.

As an example, a 2.5-10x42 SFP scope with a mildot reticle will typically be setup to subtend correctly at 10x, meaning that when on 10x the distance from each dot is 1 MIL. So if your ballistic chart tells you to hold off 2 MILS for a given distance then you simply use the 2nd mildot to hit the target. But if you are on 5x the correct subtention between dots is 2MILs. The power dropped in half so the correct subtention doubled. So now to hold over 2 MILs, like in the example above, you only need to drop down and use the 1st mildot to hit dead on. At 2.5x 1 mildot would subtend 4 MILs so for me to hit dead on I would need to hold in between the cross hair and the 1st mildot at the 1/2 MIL point in order to have a hit on target.

With an FFP scope it wouldn't matter what magnification setting you had your scope on because the reticle changes size in relation to the target so the subtention is correct over the entire magnification range.

This may lead to asking about what the negatives to a FFP scope are. IMO not many.

* The reticle size, and your ability to see the details of the reticle, drops as the magnification setting goes down. Fortunately, the majority of the times you would need a lower power magnification, closer shots, running shots, etc., you aren't going to be in need of additional hold off points. The main reticle cross is all that you will need to make the shot. And in today's market I have seen very few FFP reticles that aren't acceptable for this use.
* On the flip side as power goes up the reticle lines could become too thick for what some people would want for exact aiming and bullet placement. IMO for big game hunting this is a complete non-issue. Having said that I am not a big fan of high power scopes with 5-6x erectors on them. I do still use SFP reticles on my varmint guns but there are a couple FFP reticles that I am going to try out that seem thin enough to allow success.
* They are more expensive than their SFP counterparts.

HTH,

Scot E.
Reply With Quote
  #5  
Old 11-14-2011, 08:05 PM
Gold Member
 
Join Date: Apr 2010
Location: NW Mt.
Posts: 600
Re: Explain benefits of front focal plain

I think the Germans used FFP because it was a bit more accurate and a little more
reliable from a construction standpoint. With todays manufacturing I don't believe those
reasons have much importance anymore. I can't remember all the details as to why
but I do remember reading it way back.
Reply With Quote
  #6  
Old 11-14-2011, 08:33 PM
Bronze Member
 
Join Date: Nov 2011
Location: Colusa c
Posts: 67
Re: Explain benefits of front focal plain

Very informative.......thanks guys
Reply With Quote
  #7  
Old 11-14-2011, 08:52 PM
Platinum Member
 
Join Date: Feb 2007
Location: Townsend, Montana.
Posts: 7,915
Re: Explain benefits of front focal plain

If you intend to range with reticles,,, the FFP has advantages. But if you intend to range with a laser RF then you may prefer the Second focal plane. I like the SFP because as the power is increased the target gets larger but the reticle stays the same. So this allows a more precise point of aim at extended distances due to less target being covered by crosshairs, in my opinion. Since I never range with reticles or use the hold over methods , the SFP is more precise for me.

Jeff
__________________
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Explain benefits of front focal plain
Thread Thread Starter Forum Replies Last Post
Nightforce 3.5 - 15 X 50 NXS F1 - Front Focal Plane | Reticle? CentreHit Long Range Scopes and Other Optics 4 10-28-2011 03:24 AM
Front Focal Plane or Back Focal Plane Scope Reticle??? Rather Be Hunting Long Range Scopes and Other Optics 14 06-15-2011 07:24 PM
Shepherd Scope V1A -Front focal plane theodore Optics For Sale 2 03-14-2010 09:52 PM
Leupold ERT 8.5-25x50mm Front Focal Plane Mark 4's in stock w/ TMR & Mil Dot Reticles Don - In Idaho Optics For Sale 0 10-04-2007 12:58 PM
Leupold Front Focal Plane Mark 4's finally in stock Don - In Idaho Optics For Sale 0 10-04-2007 09:59 AM


All times are GMT -5. The time now is 03:36 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC