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Thread: FFP against SFP Scopes.?

  1. #1
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    FFP against SFP Scopes.?

    I have a question please.

    I have a sfp scope and it is zeroed to 40 yds if I shoot at 30yds or 50yds I need to take into account mil Dots up or down to be on target.

    If I get a FFP scope will I still need to do the same mildot adjustment to be on target or will it be on target if I zoom in at 50 and zoom out at 30??

    Is it just the recital that changes??

  2. #2
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    I've just got my first ffp & it's all rocket science. I shoot mostly within 8x to 12x range & slowly finding out myself. I'm thinking, from what I've seen of ffp & my needs for hunting I'll be staying with Sophie scopes.
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  3. #3
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    You will always need to use your mil dot adjustments if shoot above or below your scopes zero.
    With an FFP escape, your reticle will change in size as you increase or decrease zoom on your scope
    so your mil dot calculations will remain constant regardless of the chosen zoom you use.
    With an SFP scope, the reticle remains the same size regardless of the magnification your using.
    The mil dot calculation will be set to a specific magnification.

    ATB,

    JP

  4. #4
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    Quote Originally Posted by Tonynw1 View Post
    I have a question please.

    I have a sfp scope and it is zeroed to 40 yds if I shoot at 30yds or 50yds I need to take into account mil Dots up or down to be on target.

    If I get a FFP scope will I still need to do the same mildot adjustment to be on target or will it be on target if I zoom in at 50 and zoom out at 30??

    Is it just the recital that changes??
    The POA of the centre + act exactly the same way on both FFP & SFP.

    What changes is how the scope substrates (be they mil-dots, milrads, or random marks), act when you change magnification.

    With SFP the image gets bigger with more mag but the ret stays the same size so 1 dot holdover at 4x moves the POI 4 times as much as 1 dot holdover at 16x.
    Because of this, the SFP Mil-Dot is only "true" as a unit of measurement, at 1 specific level of magnification, usually 10x but sometimes 20x on higher mag scopes.

    With FFP the image and the ret change size together, so 1 dot holdover at 4x is the same as 1 dot holdover at 16x.

    see here; 4x FFP is slightly off because the ret is pretty small but then I don't usually use 4x at 25yds

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    Last edited by angrybear; 09-08-2022 at 08:00 PM.

  5. #5
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    For the benefit of amateurs like me, I wish people would elucidate at least once what those TLAs mean.

    [Three Letter Acronyms]
    P1V1overT1=P2V2overT2

  6. #6
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    Quote Originally Posted by Antoni View Post
    For the benefit of amateurs like me, I wish people would elucidate at least once what those TLAs mean.

    [Three Letter Acronyms]
    FFP - First Focal plain
    SFP - Second Focal Plain
    POA - Point of Aim
    POI - Point of Impact
    MOA - Minute of Angle, imperial aiming system, 1 MOA = 1" @ 100yds, 10" @ 1000yds (near as damn it)
    MRAD - Milliradian, Metric aiming system, 1 MRAD = 10cm @ 100m - 1m @ 1000m
    Mil-dot - Milliradian dot, 1 Mil-dot = 3.6" at 100yds / 10cm at 100m.

    MOA, MRAD & Mil-Dot are all measurements of angle, therefore they increase with range, and in SFP a Mil-Dot will only be "true" at 1 stated mag level.
    Last edited by angrybear; 09-08-2022 at 10:22 AM.

  7. #7
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    Jesim1 is offline Can juggle 3 pineapples but not 4!!!!
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    My views on these are well known, for air rifle distances I find little value in a FFP scope, it's different using a full bore rifle at 6oom for dear with a 3-9x40 scope, but for an air rifle zeroed at say 35m, your known holdover/under between 12m and 38m is only about 1cm up/down, which is just too small to me trying to mess around with the tiny ret increments on a FFP scope if zoomed out. So you then just use the FFP scope zoomed in - and therefor waste the point of a FFP scope

    Your local to me and I have both types, if you want to drop in for a coffee and a chat then you can try them both out and make up your own mind if they suit you

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  8. #8
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    Quote Originally Posted by Tonynw1 View Post
    I have a question please.

    I have a sfp scope and it is zeroed to 40 yds if I shoot at 30yds or 50yds I need to take into account mil Dots up or down to be on target.

    If I get a FFP scope will I still need to do the same mildot adjustment to be on target or will it be on target if I zoom in at 50 and zoom out at 30??

    Is it just the recital that changes??
    Try this example, no shooting involved;

    Put a ruler at 25yds aim at 0 note where 1 dot is, now change the mag, again aim at 0 note where the dot has moved,
    repeat changing mag each time and you will see that at lower mag 1 dot measures more than at high mag.

    With FFP 1 dot would measure 23mm at 25yds for every magnification.

  9. #9
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    I had a similar discussion while shooting on Sunday. Having recently got an FFP scope, I can say, at lower magnifications the reticle is getting so small it becomes, for me, unusable. As most (all) of my shooting does not involve changing magnification between shots (indeed 3 out of 5 of my scopes are fixed magnification), there is no disadvantage of me using a SFP. So, why did I buy a FFP? Because I liked the glass and the reticle featured a centre dot, and my eyes centre circles far more intuitively than cross-hairs.

    But all to their own when it comes to scope preferences.

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