Parallax focus

[someguy2800]

Anything over 12x it almost needs to be parallax adjustable. I prefer adjustable on anything bigger than a 3-9x40. The only scopes I currently have in the 15-16x magnification range are a sig tango 4 4-16x44, and an athalon midas 4-16x44.

The athalon has a very short depth of field like you describe yours as being.

The sig is pretty good. If I set the focus to 100 yards and the power to 4x, it is in reasonable focus from about 7 yards to infinity. With the power set to 16x it is in reasonable focus down to about 50 yards. If you needed sharp focus on 16x and less than 50 yards you can adjust it down.

I have had other 3-15 and 4-16 scopes but I don't remember any of them with enough detail to make a recommendation.

 

[someguy2800]

For 100 yard max shooting I would buy something smaller, perhaps a 3-9, 2-10, or even a 1-8 depending on what kind of shooting you do. Even if I have the extra magnification available I typically don't use more than 10x out to 200 or 300 yards.

 

[Varminterror]

Do I not want a scope with variable parallax for a 100yd 5.56 AR?

Rather you don’t NEED adjustable parallax focus when only shooting 100yrds (and only 100, not more, not less), because most fixed parallax scopes will have parallax set for 100 yards. No need to dial when it’s already dialed. But it’s kinda like a stopped clock being correct twice per day - purely coincidental.

 

[wiscoaster]

Yeah, that's what I'm trying to figure out here. Do I not want a scope with variable parallax for a 100yd 5.56 AR?

Your problem isn't at 100 yds; it's that you're also trying to use the scope for ranges under 100 yds. An adjustable parallax scope isn't appropriate for that type of usage.

 

[Walkalong]

Your problem isn't at 100 yds; it's that you're also trying to use the scope for ranges under 100 yds. An adjustable parallax scope isn't appropriate for that type of usage.

It sure is helpful when shooting small targets and want to see detail, and not just of the targets. But yea, as I said earlier, does he need a parallax adjustable scope to shoot at up to 100 yards, and a bit further? No, he doesn't.

I recently shot my first NRL-22 match, and we shot as close as 35 yards, at as small as 1/4" targets, so a crystal clear sight picture really helped.

As with many things, the application dictates the needs/wants.

 

[wiscoaster]

I think for the OP's application a typical "rimfire" scope with a 50-yd fixed focus and a 2x-6x magnification would fit the bill perfectly. Something on the order of a Vortex Crossfire II:

https://vortexoptics.com/vortex-crossfire-ii-2-7x32-rimfire-vplex-moa-riflescope.html

 

[Nature Boy]

For target work you can’t have too much magnification, regardless of distance. The only limiting factors are environmental conditions and your wallet

 

[Atavar]

Yeah, that's what I'm trying to figure out here. Do I not want a scope with variable parallax for a 100yd 5.56 AR?

If you are shooting a set distance - i.e. 100 yards then no, you do not need adjustable parallax.

However, if you ever try shooting 300 or 500 yards you will find it invaluable.

What you could do is adjust the parallax turret for different common distances and make a mark on the turret for each to help you quickly adjust for the distances you commonly use. You could use whiteout or some other easily removable marker.

 

[JEBruns]

I think for the OP's application a typical "rimfire" scope with a 50-yd fixed focus and a 2x-6x magnification would fit the bill perfectly. Something on the order of a Vortex Crossfire II:

https://vortexoptics.com/vortex-crossfire-ii-2-7x32-rimfire-vplex-moa-riflescope.html

I had a Crossfire II. Was not as clear as I liked, so took it back for a Strike Eagle. That is a nice scope, but I'm not in love with the reticle. Neither have parallax adjustment and give the same focus from 25-100 yards. My new Zeiss is a little sharper at any of those ranges, but requires focus/parallax adjustment at each distance change. I just need to figure out if the pluses outweigh the minuses to decide whether to keep it or not. And I need to get the bride out to the range to see what she thinks.

I appreciate everyone's input.

 

[JEBruns]

If you are shooting a set distance - i.e. 100 yards then no, you do not need adjustable parallax.

However, if you ever try shooting 300 or 500 yards you will find it invaluable.

As I've mentioned, I will not be shooting anything over 100 yards, but will be shooting at multiple distance up to 100 yards.

What you could do is adjust the parallax turret for different common distances and make a mark on the turret for each to help you quickly adjust for the distances you commonly use. You could use whiteout or some other easily removable marker.

Yep, that is an option. Thanks.

 

[JEBruns]

Your problem isn't at 100 yds; it's that you're also trying to use the scope for ranges under 100 yds. An adjustable parallax scope isn't appropriate for that type of usage.

I understand your point. So again I'd ask, what is a good higher end scope with 14ish max magnification with no parallax adjuster? It has to be relatively short and light for my AR application. Or is this just a non-starter in higher end optics over 9 or so magnification?

 

[Atavar]

I am afraid that at the magnifications you are talking about adjustable parallax correction becomes necessary.
It could be that you are being confused by having the parallax adjustment on a side turret instead of having a distance adjuster right in front of the eyepiece like they did on older scopes. If that is the case you can look at one of the scopes that offer the adjustment on the barrel.
Take a look at the Leupold VX-3 as an example. https://ads.midwayusa.com/product/1023058753?pid=543990

 

[Walkalong]

I believe if you give it a chance you will very soon get used to adjusting parallax and then enjoy the benefits it brings.

If you don't think that will be true for you and the wife, then buy a nice scope with fixed parallax at 100 yards ( a large percentage of fixed parallax scopes are, specs should say), and it will work very well for your purposes.

 

[jmr40]

Your problem isn't at 100 yds; it's that you're also trying to use the scope for ranges under 100 yds. An adjustable parallax scope isn't appropriate for that type of usage.

I disagree. I don't NEED an adjustable parallax scope on my centerfire rifles since I don't need anything over 9X or 10X for what I do most of the time. 600 yards is as far as I shoot, and I have no issues doing that with a scope with 6X to 10X on the top end.

But I do have one adjustable parallax scope on a 308, and another on a 22. The one on the 22 is used the most. I shoot it at ranges from 25 to 250 yards and I find adjusting the parallax at ranges under 100 yards far more helpful than ranges over 100 yards

 

[Atavar]

This is the best explanation of why parallax correction is necessary and why it works. It’s a very short video and very worth your time to watch.

 

[JEBruns]

This is the best explanation of why parallax correction is necessary and why it works. It’s a very short video and very worth your time to watch.

Thanks, that is a good video, but as I said in the first post of this thread, I understand the how/why of adjusting parallax.

 

[Walkalong]

But remember, if your eye is perfectly centered in the scope, there is no parallax. One way to do this is have your eye a hair too close or a hair too far from the scope, leaving a thin black ring around the inside, just make that even all around and you're centered. Even with parallax adjustable scopes, striving to have you eye centered is a good thing.

 

[JEBruns]

I am afraid that at the magnifications you are talking about adjustable parallax correction becomes necessary.

You could be right on the money here. But I'll search around some.

It could be that you are being confused by having the parallax adjustment on a side turret instead of having a distance adjuster right in front of the eyepiece like they did on older scopes. If that is the case you can look at one of the scopes that offer the adjustment on the barrel.
Take a look at the Leupold VX-3 as an example. https://ads.midwayusa.com/product/1023058753?pid=543990

I'm not confused by that. Actually, if I have to adjust it, I'd prefer it to be on the side. But thanks for the suggestion.

 

[Atavar]

When I was a kid they just told us it was an adjustment to focus at a distance. They didn’t want to confuse our developing brains with discussions of parallax. Lol

 

[JEBruns]

I see Leupold carries on that tradition in their marketing. They actually call it a "side focus" knob.

 

[wiscoaster]

For target work you can’t have too much magnification, regardless of distance. ....

For serious competition, perhaps, but for recreational target shooting my own rule-of-thumb is no magnification under 100 yds: irons and red dots only for less than 100 yds. The rifles equipped with permanently mounted scopes are necessity-based exceptions but they are all fixed-focus scopes and when shot under 100 yds I dial down the magnification to whatever their minimum is. My issues have more to do with eye relief than with target focus. I suppose this approach simplifies my own scope selection but also explains my POV toward the OP's dilemma.

 

[Walkalong]

When I could still see, I had no need for magnification at 100 yards or less either, unless I was trying for serious groups. Now? Not so much.

 

[someguy2800]

When I could still see, I had no need for magnification at 100 yards or less either, unless I was trying for serious groups. Now? Not so much.

I was born that way!

 

[Varminterror]

I see Leupold carries on that tradition in their marketing. They actually call it a "side focus" knob.

Technically, we ARE focusing with an adjustable objective or side focus knob. We are focusing the images of the reticle and the target together into the same plane.

 

[Varminterror]

Despite having searched multiple times, I have not found any mathematical or physical evidence to support that magnification influences parallax error. Lots of folks claim magnification increases error, but I’ve never found anything but anecdotal or speculative claims to support it.

Certainly, with an SFP reticle, the relative proportion of the error size to the reticle would change with magnification, but I’ve not seen anyone provide the mathematics to explain any actual magnification influence on parallax.

Personally, I think this claim is based on mistaken inference from two field observations - at higher magnification, 1) we have shallower depth of field, so our parallax focus becomes more critical (more difficult to align), and 2) at high magnification, we can see the reticle “moving” against the target more easily, so we mistakenly assume it’s moving more. Just like the claim guys have that high magnification causes them to wobble more on target - nah, they just couldn’t tell they were wobbling when shooting at lower magnification…

The formula to calculate maximum potential parallax error is:

+/- (objective diameter)/2 * abs(real range - parallax setting)/parallax setting

So the maximum potential error - in any direction - when shooting a 40mm objective with a 100yrd parallax at 50 yards is 40/2 * abs(50-100)/100 = 10mm. Alternatively, shooting a 50yrd parallax at 100yrds would allow up to 20mm of error.

Conceding - this is the MAXIMUM potential error, and if your eye is close to center, you won’t realize that much error. But given tools to eliminate the problem entirely, do so.