Rifle Scopes Zero shift when changing power on SFP scopes

eff10mm

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Minuteman
Nov 9, 2012
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I have always heard about a zero shift when zooming a SFP scope. Is this really true or is it more of a cheap scope phenomenon from poor parts and assembly? For long range varmint shooting I have alway used SFP scopes to keep the reticle from zooming to large to obscure my target, but I wonder how much error I introduce by changing power. If this shift is occuring what kind on scale are we talking?
 
Re: Zero shift when changing power on SFP scopes

Zero shift when changing power should not happen on good glass. You hit the nail on the head, it is a cheap scope phenomenon from poor parts and assembly. (to use your words). If you have sub par glass- the only way to tell is to shoot at a range at both extremes of your magnification- and see the shift on your target.
 
Re: Zero shift when changing power on SFP scopes

It could happen on any scope. But the better the build quality , the less pronounced it will probably be. Or if you will be able to discern the difference while shooting...
 
Re: Zero shift when changing power on SFP scopes

I think I remember reading something on a link from US Optics about the shift and what I gathered was that it was inherent to all scopes in the second focal plane. Has anyone seen a shift when testing and if so how much?
 
Re: Zero shift when changing power on SFP scopes

Are you thinking about the reticle's milling marks not being accurate with a SFP reticle at all magnifications?
 
Re: Zero shift when changing power on SFP scopes

The trait that is common amongst Second Focal Plane (SFP) optics is known as "Between Power Deviation". It is the occurrence of reticle movement as the erector changes magnification which in turn creates a change in the POI from the POA as much as 2moa throughout the power zoom range.

It is a trait that is more common than one may think. Also possible in FFP, just more prevalent in SFP scopes. It is something you will absolutely not find in a Nightforce.

 
Re: Zero shift when changing power on SFP scopes

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body">It is something you will absolutely not find in a Nightforce.

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As the owner of more than a few NightForce scopes and having just got another F1 in the mail...... I will ask you this.

You sure about that? Bold statement.

I am a huge NightForce fan, but to make a statement as fact, such as you did..... that can and has been proven to be false could blow up in your face.
 
Re: Zero shift when changing power on SFP scopes

Let's put it this way. Every single scope that leaves the NF Factory has been QC inspected and wears the label to show such. It would not pass if there was any Between Power Deviation present as it is one of the points on the 70+ point QC inspection checklist. And to my knowledge, there has not been one returned with that complaint for warranty in 10 years.

I am very confident in my statement. If a Nightforce exists that exhibits any "Between Power Deviation", we would like to see it.
 
Re: Zero shift when changing power on SFP scopes

Not something that I or many other people would send a scope back for. It's a common issue in SFP scopes.

Simple as putting a bore sight device on the muzzle and running the scope through the range of power. I didn't believe it about a nightforce until I saw it. I actually argued the fact. I ate crow.

Not a slam on NF scopes by any means, but it happens.
 
Re: Zero shift when changing power on SFP scopes

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RussW1911 ®</div><div class="ubbcode-body">Not something that I or many other people would send a scope back for. It's a common issue in SFP scopes.

Simple as putting a bore sight device on the muzzle and running the scope through the range of power. I didn't believe it about a nightforce until I saw it. I actually argued the fact. I ate crow.

Not a slam on NF scopes by any means, but it happens.</div></div>

How much reticle movement did you witness?
 
Re: Zero shift when changing power on SFP scopes

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body"> It is something you will absolutely not find in a Nightforce.
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This is why I buy NF and will continue to... One of mine has taken a serious beating and just keeps on trucking...
 
Re: Zero shift when changing power on SFP scopes

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RussW1911 ®</div><div class="ubbcode-body">Not something that I or many other people would send a scope back for. It's a common issue in SFP scopes.

Simple as putting a bore sight device on the muzzle and running the scope through the range of power. I didn't believe it about a nightforce until I saw it. I actually argued the fact. I ate crow.

Not a slam on NF scopes by any means, but it happens.</div></div>

How much reticle movement did you witness?


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Only about a minute. I saw much worse out of a Premier when I started checking everything. As stated before, it's not only SFP scopes. It's not a deal breaker on the scope for me. I don't have an issue with the fact that a mechanical device isn't perfect. I have an issue with a statement being made that is just not true.
 
Re: Zero shift when changing power on SFP scopes

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RussW1911 ®</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 00bullitt</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RussW1911 ®</div><div class="ubbcode-body">Not something that I or many other people would send a scope back for. It's a common issue in SFP scopes.

Simple as putting a bore sight device on the muzzle and running the scope through the range of power. I didn't believe it about a nightforce until I saw it. I actually argued the fact. I ate crow.

Not a slam on NF scopes by any means, but it happens.</div></div>

How much reticle movement did you witness?


</div></div>

Only about a minute. I saw much worse out of a Premier when I started checking everything. As stated before, it's not only SFP scopes. It's not a deal breaker on the scope for me. I don't have an issue with the fact that a mechanical device isn't perfect. I have an issue with a statement being made that is just not true.

</div></div>

Our scopes do not have that amount of deviation.

If yours does, I urge you to send it back to us. If you personally witness more than 1/8moa then your scope has an issue and we need to address it as it did not leave the factory that way as it is outside of spec.

If you send it in and it does in fact have deviation, you will be the first scope of record to have been repaired for such.
 
Re: Zero shift when changing power on SFP scopes

I have switched to all Mil/Mil scopes and all FFP.

As I said, not a deal breaker, but I found your statement questionable. While you may believe what you said is true, users of the product may not agree. not only that, I doubt 99% of the users out there check for this. They adjust numbers in their ballistics program to get "close enough" on target.
 
Re: Zero shift when changing power on SFP scopes

most of us magnificaton hoe's always shoot on max power anyway unles shooting close in fast pace styles of shooting unless marrage doesn't permit.

I have, but rarely shoot on min power. no issues with shift on my two NF scopes.
 
Re: Zero shift when changing power on SFP scopes

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JWP6114</div><div class="ubbcode-body">most of us magnificaton hoe's always shoot on max power anyway unles shooting close in fast pace styles of shooting unless marrage doesn't permit.

I have, but rarely shoot on min power. no issues with shift on my two NF scopes. </div></div>

As you shouldn't. If there is movement beyond the thickness of the reticle, there is an issue that occurred after it left our factory and your scope requires warranty service.

I still stand firm in my statement, that NF scopes do not have deviation issues between power. While it is common in SFP scopes, it is not common in NF.
 
Re: Zero shift when changing power on SFP scopes

Thanks for everyones input this has been educational. I assume the shift can be in the windage as well as elevation. 2 MOA is a huge change when shoot even mid-range distances.