Question about mildots and distance
- Thread starter sarduy
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burrhead
Member
Your scope appears to be a SFP. You have to set the magnification to the power at which your scope's subtension is correct. Usually, but not always, it will be the highest magnification. That info will be in the owner's manual or online.
Here's the math:
Target size (yards) x 1000
________________________
MRADS read = range in yards
Target size (inches) X 27.8
_________________________
MRADS read = range in yards
Here's the math:
Target size (yards) x 1000
________________________
MRADS read = range in yards
Target size (inches) X 27.8
_________________________
MRADS read = range in yards
Last edited:
OP
OP
sarduy
Member
The scope is a 6-24x50
burrhead
Member
SFP scopes have a specific magnification for ranging. For example, my Vortex Viper HS-T 6-24X50 has to be put at 18X for the reticle to have correct subtension to calculate the range. Your's may be different and the manufacturer will tell you. That is the advantage of FFP scopes; the subtension is correct at all magnifications. Unless we know what scope you have we can't help you; not enough info.
SFP = secondary focal plane (most lesser expensive scopes) They're usually set for the Mil Dots to be at the standard spacing at the maximum zoom. So if it isn't set on the highest magnification, you have the additional calculation of the highest magnification / the current setting X the calculated range.
FFP is first focal plane. The mil dots will be at the proper spacing with any magnification setting. This is most common on high end scopes.
If it's the Viper Vortex that I'm envisaging, it's FFP.
http://www.mil-dot.com/user-guide
FFP is first focal plane. The mil dots will be at the proper spacing with any magnification setting. This is most common on high end scopes.
If it's the Viper Vortex that I'm envisaging, it's FFP.
http://www.mil-dot.com/user-guide
burrhead
Member
"If it's the Viper Vortex that I'm envisaging, it's FFP."
Stoky, if you're directing that to me, The Viper HS-T is a SFP.
http://www.vortexoptics.com/product/vortex-viper-hs-t-6-24x50-riflescope-with-vmr-1-moa-reticle
Stoky, if you're directing that to me, The Viper HS-T is a SFP.
http://www.vortexoptics.com/product/vortex-viper-hs-t-6-24x50-riflescope-with-vmr-1-moa-reticle
lysanderxiii
Member
If the dots get closer together as you zoom out, it's FFP.
If the reticle stays the same size, it's SFP.
Simple
If the reticle stays the same size, it's SFP.
Simple
It will definitely help to know exactly what scope you have before any of us can help. Each manufacturer sets their scopes different. I have an older Bushnell 4200 Elite 6-24x50 scope and the Mil Dot is calibrated at 12x power and is exactly half of that at 24X and double at 6X. I know Nikon Mil Dot scopes are usually calibrated at the highest magnification.
coloradokevin
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Others have already pretty much covered this, but just to give you a touch of clarification here:
SFP (Second Focal Plane) Scopes:
These represent the majority of scopes on the market, including almost all of the scopes you would buy at hunting stores, sporting goods stores, etc. In these scopes the reticle looks like it is the same size no matter what magnification level you are at. When you adjust the magnification the subject will appear to change size, but the reticle will appear to stay the same. As such, the mildots will cover a different portion of the target. And, because of that, you need to know what specific magnification your manufacturer used to make the mildots "correct" on target. This is usually the highest magnification setting, but not always. Check with your scope manufacturer!
FFP (First Focal Plane) Scopes:
These scopes aren't as common, and you'll likely know if you have one. With one of these scopes the reticle and the subject both appear to change size proportionally as you adjust the magnification power of the scope. As such, the mildots will continue to cover the exact same amount of the target as you zoom in and out. The reticle will appear to be smaller at low magnification, and larger at high magnification. In these scopes the mildot measurement is always consistent.
SFP (Second Focal Plane) Scopes:
These represent the majority of scopes on the market, including almost all of the scopes you would buy at hunting stores, sporting goods stores, etc. In these scopes the reticle looks like it is the same size no matter what magnification level you are at. When you adjust the magnification the subject will appear to change size, but the reticle will appear to stay the same. As such, the mildots will cover a different portion of the target. And, because of that, you need to know what specific magnification your manufacturer used to make the mildots "correct" on target. This is usually the highest magnification setting, but not always. Check with your scope manufacturer!
FFP (First Focal Plane) Scopes:
These scopes aren't as common, and you'll likely know if you have one. With one of these scopes the reticle and the subject both appear to change size proportionally as you adjust the magnification power of the scope. As such, the mildots will continue to cover the exact same amount of the target as you zoom in and out. The reticle will appear to be smaller at low magnification, and larger at high magnification. In these scopes the mildot measurement is always consistent.
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