SFP mildot

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SFP mildot

Post by Chappo » 29 Mar 2019, 7:25 pm

What’s the point of a bdc or mildot on a sfp?
Please educate someone who’s only ever used sfp plain / plex reticles.
Just considering the options for a new scope......
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Re: SFP mildot

Post by SCJ429 » 30 Mar 2019, 9:05 am

Perhaps for shooters that find it impossible to dial the adjustment you would know the hold over value at commonly used magnifications such as 25x and 12x. For me I would just use them for references when holding off.

For me the FFP sucks when adjusting the magnification as the reticals goes from too heavy to too fine especially when using it in low light conditions.
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Re: SFP mildot

Post by on_one_wheel » 30 Mar 2019, 10:12 am

Mill dot scopes are used for ranging distance.

Have a look on YouTube. There's several good videos explaining how they work.
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Re: SFP mildot

Post by Chappo » 30 Mar 2019, 10:23 am

Yeah I get how they work but on a sfp scope you can only use them at set magnifications.
As soon as you dial up or down they are no longer accurate.
Maybe like scj said, learn your holdovers on the most commonly used magnifications only?
Seems harder than using a plain reticle to me.
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Re: SFP mildot

Post by bladeracer » 30 Mar 2019, 2:17 pm

Chappo wrote:What’s the point of a bdc or mildot on a sfp?
Please educate someone who’s only ever used sfp plain / plex reticles.
Just considering the options for a new scope......


Same point as in a FFP scope, for holding over and rangefinding.
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Re: SFP mildot

Post by bladeracer » 30 Mar 2019, 2:21 pm

Chappo wrote:Yeah I get how they work but on a sfp scope you can only use them at set magnifications.
As soon as you dial up or down they are no longer accurate.
Maybe like scj said, learn your holdovers on the most commonly used magnifications only?
Seems harder than using a plain reticle to me.


You can use the reticle at any magnification. It is calibrated at one magnification though, usually maximum, but sometimes at the best exit pupil magnification.
BDC are not designed for precision shooting, and significant holdover is rarely needed under about 300m. Past 300m you most likely are well set up and have time to range the target and dial the scope up to suit. Holding over imparts cant into the reticle so for precision you want to dial the scope to allow a dead-on hold.
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Re: SFP mildot

Post by bladeracer » 30 Mar 2019, 2:23 pm

SCJ429 wrote:Perhaps for shooters that find it impossible to dial the adjustment you would know the hold over value at commonly used magnifications such as 25x and 12x. For me I would just use them for references when holding off.

For me the FFP sucks when adjusting the magnification as the reticals goes from too heavy to too fine especially when using it in low light conditions.


My neighbour bought a pair of Athlon's recently, one SFP and one FFP. The FFP is virtually useless for field work for me as the reticle is invisible at low-magnification against any background other than a paper target. At higher-magnification it becomes usable, but I think it's designed primarily for punching paper. The SFP is more useful.
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Re: SFP mildot

Post by Kel » 31 Mar 2019, 5:25 pm

bladeracer wrote:
SCJ429 wrote:Perhaps for shooters that find it impossible to dial the adjustment you would know the hold over value at commonly used magnifications such as 25x and 12x. For me I would just use them for references when holding off.

For me the FFP sucks when adjusting the magnification as the reticals goes from too heavy to too fine especially when using it in low light conditions.


My neighbour bought a pair of Athlon's recently, one SFP and one FFP. The FFP is virtually useless for field work for me as the reticle is invisible at low-magnification against any background other than a paper target. At higher-magnification it becomes usable, but I think it's designed primarily for punching paper. The SFP is more useful.


That's probably a good case for an illuminated reticle on the FFP.
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Re: SFP mildot

Post by bladeracer » 31 Mar 2019, 6:31 pm

Kel wrote:
bladeracer wrote:
SCJ429 wrote:Perhaps for shooters that find it impossible to dial the adjustment you would know the hold over value at commonly used magnifications such as 25x and 12x. For me I would just use them for references when holding off.

For me the FFP sucks when adjusting the magnification as the reticals goes from too heavy to too fine especially when using it in low light conditions.


My neighbour bought a pair of Athlon's recently, one SFP and one FFP. The FFP is virtually useless for field work for me as the reticle is invisible at low-magnification against any background other than a paper target. At higher-magnification it becomes usable, but I think it's designed primarily for punching paper. The SFP is more useful.


That's probably a good case for an illuminated reticle on the FFP.


Perhaps, but the reticle is so incredibly fine I'm not sure it'd help.
I'm not a fan of illuminated reticles though.
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Re: SFP mildot

Post by Kel » 02 Apr 2019, 12:19 pm

bladeracer wrote:
Kel wrote:
That's probably a good case for an illuminated reticle on the FFP.


Perhaps, but the reticle is so incredibly fine I'm not sure it'd help.
I'm not a fan of illuminated reticles though.



Fair enough, having said that I have a very fine FFP illuminated reticle on an S&B 5-25x56 PMII and I do find the illumination compensates nicely for the fine nature of the reticle on low power magnification.
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Re: SFP mildot

Post by SCJ429 » 02 Apr 2019, 7:31 pm

I have the same S&B and even at the lowest power setting the illuminated dot covers a lot of the target. Better than not being able to see the retical at all though. I find that even when it is quite dark the scope gathers enough light to see the target. If you can keep the magnification up you can see the cross hair but below 10x it is way too fine.
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Re: SFP mildot

Post by DropBear » 17 May 2019, 8:07 pm

It seems pretty stupid at first glance to put MIL/MOA/BDC reticles in SFP scopes. In some cases it definitely makes you wonder if the manufacturers have a clue at all - for example Hawke have the VANTAGE 3-9×40 AO MIL DOT. The reticle is calibrated for 10x power! WTF? They also have fixed power scopes such as the 4x32 with the same reticle - no idea what they were thinking..

Given that, I have a couple of SFP Vortex scopes with BDC reticles that are calibrated for standard calibre performance at max magnification. They work very well within "Minute of rabbit/pig etc" expectations for hold over over the nominated ranges. Reduce the magnification (as the range befits) and then it becomes more guesswork and gut instinct, but up close it is not an issue.

Some manufacturers have taken it a step further with the SFP scopes and they use the fact that the BDC value varies with magnification to make the range marks work with numerous calibres and ammunition performance variables at different zoom values. Zeiss for example have a phone app that tells you what power to set your scope to using the ballistic variables specific to your load data and environmental conditions and then gives you impact distance for each marker on the reticle (e.g. RZ800 reticle).

I prefer FFP for consistent long range performance and unless I plan to shoot entirely in the day and only at targets I will have an illuminated reticle on my FFP scopes. For short range I would use plex or something similar but I wouldn't rule out educated use of SFP BDC for occasional range stretching on my hunting platform.
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Re: SFP mildot

Post by bladeracer » 19 May 2019, 7:45 am

DropBear wrote:Some manufacturers have taken it a step further with the SFP scopes and they use the fact that the BDC value varies with magnification to make the range marks work with numerous calibres and ammunition performance variables at different zoom values. Zeiss for example have a phone app that tells you what power to set your scope to using the ballistic variables specific to your load data and environmental conditions and then gives you impact distance for each marker on the reticle (e.g. RZ800 reticle).


You can calculate your reticle differences through the range of magnification with any scope, you don't need the manufacturer to build one specially to allow that.
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Re: SFP mildot

Post by DropBear » 19 May 2019, 4:06 pm

bladeracer wrote:
DropBear wrote:Some manufacturers have taken it a step further with the SFP scopes and they use the fact that the BDC value varies with magnification to make the range marks work with numerous calibres and ammunition performance variables at different zoom values. Zeiss for example have a phone app that tells you what power to set your scope to using the ballistic variables specific to your load data and environmental conditions and then gives you impact distance for each marker on the reticle (e.g. RZ800 reticle).


You can calculate your reticle differences through the range of magnification with any scope, you don't need the manufacturer to build one specially to allow that.


That's a great point. Straightforward when you know the base subtension values for the reticle - such as those in standard MIL and MOA values. It gets a little more complicated with the BDC reticles like the Zeiss RZ800 etc when manufacturers don't publish the subtension for the holdover markings on their reticles.
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Re: SFP mildot

Post by bladeracer » 19 May 2019, 4:29 pm

DropBear wrote:That's a great point. Straightforward when you know the base subtension values for the reticle - such as those in standard MIL and MOA values. It gets a little more complicated with the BDC reticles like the Zeiss RZ800 etc when manufacturers don't publish the subtension for the holdover markings on their reticles.


Bushnell don't either, so I emailed and asked them :-)
But it's easy enough to work it out for yourself fairly accurately.
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