Parallax focus

[JEBruns]

Bought a Zeiss scope the other day, a V4 Conquest 4-16X44. First scope I've owned with a parallax adjuster. I understand parallax and how/why to adjust it. But what surprised me was that the parallax adjuster impacted focus a great deal. I started at 25 yards to get the scope sighted in. First look down the scope, the target was way out of focus. Finally realized I could get it sharp with the parallax adjuster. But I had to refocus with the adjuster at 50, 75 and 100 yards. Even with lower magnification levels.

I like the scope overall. Awesome reticle and very accurate, but being this is my first scope with an adjuster for parallax, I don't know if the focus issue is normal or not. I'm not happy about having to refocus for each of these ranges, and not sure the wife will deal with it well either. I put the scope on a nicer AR, and am not looking to shoot more than 100 yards with it.

So is this normal? Are there scopes with the parallax adjuster that do not suffer from this issue? If so, please let me know which brand/style they are.

 

[Atavar]

It sounds to me like it is working exactly like it is supposed to. Focus the reticle with the eyepiece adjustment and focus the target with the parallax turret.
Parallax needs to be corrected for the range to your target. This is rather in the nature of the beast.

 

[JEBruns]

So is your experience with parallax adjustable scopes the same as mine? The target is way out of focus at varying ranges inside of 100 yards.

 

[wiscoaster]

....The target is way out of focus at varying ranges inside of 100 yards.

Scopes with adjustable parallax are normally intended for use at ranges longer than 100 yards. Sorry, but I think you just bought the wrong scope for your rifle. My advice: buy a long-range precision target rifle and mount your new scope on that!!

 

[243winxb]

The eyepiece needs adjustment first. The scope should have instructions. I set the eyepiece on a target @ 100 yards, with the parallax set @100. When done with eyepiece, fine tune the parallax. The yardage marks on the scope are not always correct. Adjust for a clear target.

Fixed parallax scopes are set at about 150 yards. This works from 50 yards to Infinity.

A 22 rim fire target scope i have, needs parallax adjusted for every yardage. A real pain.

 

[rbernie]

I have never understood (stated more honestly, I have never tried to understand) how adjusting out parallax error for a given target distance makes the target visually more or less clear in a side focus optic - but that’s just the way that side focus optics seem to work.

I have always assumed that it’s an intentional optic design that allows you to spin the dial until the target is in focus and that point know that parallax error has been removed.

 

[Atavar]

What rifle do you have this scope on?

 

[Armorer 101]

If you have an adjustable parallax scope and do not adjust it properly, your groups will go to crapola. You can not go from 50 to 200 without changing the adjustment. But, there is a very real up side, you can use the adjustment knob to estimate range. Look at a target at distance, say about 3-400 yards, through the scope, turn the Parallax adjustment knob until the target is in perfect focus……read the #s indicated on the knob. You get the approximate distance. You will get used to it, it is very common on sniper or counter sniper scopes as well as target scopes as it is one thing that allows precision shooting, at distance.

 

[sarduy]

This is a common technical user issue, there’s nothing wrong with the scope, it’s working as intended. Best way to work around that is to leave the parallax at the longest range you are shooting “say 100 yards” or in the infinity ♾, then adjust the diopter to sharpen that reticle.

 

[sarduy]

I have never understood (stated more honestly, I have never tried to understand) how adjusting out parallax error for a given target distance makes the target visually more or less clear in a side focus optic - but that’s just the way that side focus optics seems to work.

I have always assumed that it’s an intentional optic design that allows you to spin the dial until the target is in focus and that point know that parallax error has been removed.

 

[Nature Boy]

The eyepiece needs adjustment first. The scope should have instructions. I set the eyepiece on a target @ 100 yards, with the parallax set @100. When done with eyepiece, fine tune the parallax. The yardage marks on the scope are not always correct. Adjust for a clear target.
View attachment 1047699

This is what I do as well, but I’m adjusting the ocular to bring the reticle into the sharpest focus while looking at either a blue sky or white background.

Then I adjust parallax based on the distance I’m shooting. It’s usually, but not always, the clearest focus on the target. To ensure you have dialed out all your parallax you move your head slightly up and down and side to side and see if the reticle is moving. Keep adjusting until you can not detect any wobble in the reticle based on your head position.

What happens when you have parallax error is you’ll end up with flyers in your group. Not that big of a deal for hunting level accuracy but for precision shooting it is. Having said all of that, if your head position is consistently in the same exact spot for every shot parallax error doesn’t play a factor

 

[Varminterror]

If your target is going out of focus as parallax is adjusted, then you have your ocular adjustment incorrect, and you are focusing your eye on the reticle, rather than the target. Set the ocular focus first, always. Once that’s set, parallax adjustment is simply bringing the reticle into the plane of the target. What you’re doing now is the opposite, which is not how the scope was designed to function, such you are chasing your tail.

 

[JFrank]

For myself it can be somewhat of a double edge sword, many times my parallax is perfect but I can’t see the target clearly and then back and forth until I’m comfortable with the sight picture and call it good enough as you can’t hit what you can’t see.

 

[CoalCrackerAl]

After i figured out what parallax was. And how to use it for shooting out past 100 yards. I fell in love with the adjustable scopes. Im also starting to get into the first focal plane scopes too.

 

[JEBruns]

This is a common technical user issue, there’s nothing wrong with the scope, it’s working as intended. Best way to work around that is to leave the parallax at the longest range you are shooting “say 100 yards” or in the infinity ♾, then adjust the diopter to sharpen that reticle.

Thanks folks. I know how to set the ocular focus. But that is set and forget. I do not mess with that once set, and you're not suppose to. But if I dial in the parallax at 100yd, a target at 25yds would be WAY out of focus. You can tell it's a target kind of, but you wouldn't want to pull the trigger w/o spinning the parallax knob a bit. The knob on my Zeiss is not numbered, BTW.

 

[JEBruns]

Scopes with adjustable parallax are normally intended for use at ranges longer than 100 yards. Sorry, but I think you just bought the wrong scope for your rifle.

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?

 

[Walkalong]

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?

No.

But if you are going to shoot multiple yardages, especially on out there say 500/600/700/800 yards, a parallax adjustable scope is very handy.

That said, and as posted, you must have the diopter set correctly for your eye.

 

[sarduy]

A 1-4 or 1-6 is more than enough for an AR at 100 yards

 

[someguy2800]

The change in focus at different distances is a seperate thing from the parallax. You'll find that some scopes the focus is affected by the range much more than others. This property in optics is called depth of field and it has to do with the spacing and angles of the lenses inside the scope. Some lower power scopes on their lowest power setting will be in reasonable focus from 10 yards to 1000 yards without adjusting the knobs, even though the parallax will only be correct at one specific range. Other scope designs you can almost use the focus/parallax adjustor as a rangefinder because they are so sensitive. Scopes with non adjustable focus such as a typical 3-9 have the lens angles designed to give a very wide depth of field. An adjustable parallax scope attempts to correct for both the depth of field in order to give a focused image, as well as correct the parallax to keep the image and the reticle on the same focal plane, but sometimes those two things don't quite match in some scopes.

Here is a video that explains how depth of field in an optic works and why some scopes have a much narrower depth of field than others.



While we are on the subject of parallax, I recommend you check all your scopes for parallax error at known ranges yourself from the bench. I don't think I have ever had a scope where the markings are accurate at all ranges. I have had scopes that need to be set anywhere from 75 to 300 on the parallax adjusted in order to be parallax free on target at 100 yards, and at longer ranges its a crap shoot if any of them will be correct. The amount of parallax error is different on various scopes as well. I have had non adjustable 3-9 scopes that have 6 inches of parallax error at 300 yards despite being in focus optically.

 

[JEBruns]

No.

But if you are going to shoot multiple yardages, especially on out there say 500/600/700/800 yards, a parallax adjustable scope is very handy.

That said, and as posted, you must have the diopter set correctly for your eye.

I do not intend to shoot further than 100yds. The diopter is set correctly.

 

[someguy2800]

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?

I prefer adjustable parallax scopes whenever I can find one suitable for what I am doing, but perhaps you don't want that particular scope if the sensitivity of the focus is a problem for you. As explained above they are not all like that.

 

[JEBruns]

The change in focus at different distances is a seperate thing from the parallax. You'll find that some scopes the focus is affected by the range much more than others. This property in optics is called depth of field and it has to do with the spacing and angles of the lenses inside the scope. Some lower power scopes on their lowest power setting will be in reasonable focus from 10 yards to 1000 yards without adjusting the knobs, even though the parallax will only be correct at one specific range. Other scope designs you can almost use the focus/parallax adjustor as a rangefinder because they are so sensitive.

That seems to be the way mine works.

So does anyone have any recommendations for a higher quality scope with at least a 15X max magnification with fixed parallax adjustment?

Zeiss is closed today (maybe all week?), so I can't ask them these questions.

 

[Walkalong]

I do not intend to shoot further than 100yds. The diopter is set correctly.

Most scopes are set parallax free at 100 yards, and will be quite usable from as close as 25 yards to 200 yards.

But you have a nice scope now that is more versatile, I’m sure you can get used to it for plinking/informal target shooting etc.

 

[Walkalong]

That seems to be the way mine works.

So does anyone have any recommendations for a higher quality scope with at least a 15X max magnification with fixed parallax adjustment?

Zeiss is closed today (maybe all week?), so I can't ask them these questions.

I wouldn’t want a 15x with no parallax adjustment.

 

[JEBruns]

I prefer adjustable parallax scopes whenever I can find one suitable for what I am doing, but perhaps you don't want that particular scope if the sensitivity of the focus is a problem for you. As explained above they are not all like that.

Ah, I did not pick up that not all are like that. So what scopes would give a deeper field of view for any given parallax setting?