Parallax in handgun shooting?

[dontcatchmany]

Have any of you noticed that when shooting a pistol (no scope) that sometimes you might cant your head/neck too much up or down or too much left or right.

I have been having spinal issues for a long time and my neck has started getting painful sometimes when I shoot my handguns. I find myself unconsciously holding my head higher or lower or more to the left or right. My point of aim / sight alignment gets off causing my shot placement to be less than perfect.

Do any of you experience times when your sight alignment is off?

I was shooting yesterday and the first 50 shots were right on, then became more off target as my neck started to be a pain.

Old age and mortar/RPG rounds when I was a young guy in Southeast Asia playing GI Johnnie..

 

[Bowdog]

Yes I do. Old age and old eyes making it harder to shoot well with handguns on anything over 15 yards. I keep a pump shotgun on hand for any real world action. Haven't had any real world action after Uncle Sam's tour of Southeast Asia 1968-69. I am hoping I neve need to. Just remember front sight ,front sight, front sight. You might be off a litter in rear sight alinement, but the hits will be good enough. It is just the way it is but we are still on the right side of the grass.

 

[Aguila Blanca]

What you have observed is real ... but it isn't parallax. Parallax only applies to optics with multiple lenses and a reticle.

 

[LeverGunFan]

What you have observed is real ... but it isn't parallax. Parallax only applies to optics with multiple lenses and a reticle.

While I agree that what he describes isn't parallax, it is incorrect to say that parallax only applies to optical systems with a reticle. The general definition of parallax is the apparent displacement of an object because of a change in the observer's point of view. A simple example is to close your left eye and hold your thumb in front a distant object using your right eye, then switch to your left eye; the apparent movement of your thumb against the background object is defined as parallax.

 

[dontcatchmany]

Bowdog, Welcome Home Brother! 68/69 for me also.

 

[Bart B.]

What you have observed is real ... but it isn't parallax. Parallax only applies to optics with multiple lenses and a reticle.

I disagree. Astronomers use parallax angles without reticles to measure distance to things in the universe.

Some definitions use optics with a reticle as an example because a 1/10 MOA or less parallax error is easy to see magnified compared to metallic sights with the unaided eye. None mandates parallax to only optical lens systems.

Parallax is the English word derived from the original Greek word used before optical lenses with reticles were used.

Parallax (from Ancient Greek παράλλαξις (parallaxis), meaning 'alternation') is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines.

Remember the barrel axis comes into this parallax thing, too

 

[JohnKSa]

It is true that parallax doesn't require lenses. It is also true that it doesn't apply to an aiming system with more than 2 objects which all must be aligned. An example of a system with 2 objects to align would be a single aiming reticle and a target--an example of a system with more than 2 objects to align would be metallic sights which require aligning 3 objects, the rear sight, the front sight and the target.

A 2 object system can have parallax if the eye is moved off axis--the reticle/aimpoint will appear to be pointing somewhere different than where it really is--but moving the eye off-axis in a system with 3 or more objects ruins the alignment of the entire system in a very observable way. There's no longer any suggestion that the system is aligned and without alignment there is no aimpoint. Without an aimpoint it's meaningless to talk about it moving.

In a 2 object system (typical scope) parallax moves the aiming point without providing obvious cues that it has moved. In a system with more than 2 objects to align (iron sight system) moving the eye off axis just ruins the aiming point entirely since it takes the front and rear sight out of alignment with each other AND with the target. It's accurate to say that there just isn't an aimpoint any longer.

I think it's probably accurate to say that 2 piece iron sight systems (having both a front and a rear sight) were developed to eliminate issues with parallax since any displacement of the eye is immediately obvious.

 

[Aguila Blanca]

https://www.6mmbr.com/parallax.html

 

[Bart B.]

https://www.6mmbr.com/parallax.html

That's for scopes.

Metallic sights have parallax, too. Moreso because there's 4 points to have on one axis. And the bore is at a fixed angle and direction from the middle two.

 

[HiBC]

I'm asking a question,rather than making a claim.

Correct me if I'm wrong,but with a scope,when you look through the "window" of the scope,ideally you sighted in with a spot weld that positions your eye centered consistently behind the scope.

If you move your eye slightly off center,your scope "window" may be forgiving enough you still see full field,but the apparent position of the reticle on the target may move.Obviously if the reticle is then moved to target,some error maybe introduced to the point of impact.

So,thats one somewhat reasonable,if imperfect (perhaps) explaination of how we see parallax through a scope.

My question: How is it that much different when I look through a peep sight?

I'm looking through a window.Ideally ,my eye will want to center in that window. Ideally,my spot weld is set up so my eye will center consistently.

If I move my eye around,I can still see through the peep,but my shots will show error on the target

What is the difference? Why wouldn't we call both parallax?


Slightly off topic,I believe a few years back,it may have been Bart B who suggested if your spot weld is good and consistent you can remove your rear sight and shoot surprisingly well.


The diameter of the peep orifice is merely a boundary to ensure your eye is centered where it is supposed to be.A very good spot weld technique can repeat pretty well.


That said,good,consistent spot weld helps counteract parallax,....True?

 

[JohnKSa]

if your spot weld is good and consistent you can remove your rear sight and shoot surprisingly well.

Having two sights to align means that if both sights are aligned properly, it doesn't matter where your eye is. Or, more accurately, if both sights are aligned properly your eye MUST be in the right place.

Having two components in different planes in the sighting system means that it's not really possible for your eye to be out of position without your knowing about it.

If I move my eye around,I can still see through the peep,but my shots will show error on the target

Merely being able to see through the peep is not the same as having the sights aligned. There's also a front sight component to the sighting system.

But yes, if you ignore the alignment of one or more of the components of a metallic sight system then you can end up with parallax because now you're effectively using a system with only 2 components--a target and a single sight. As long as you pay attention to the alignment of both of the sights (front and rear) any significant issues with eye positioning will immediately result in visible misalignment of the sights with each other.

 

[HiBC]

Merely being able to see through the peep is not the same as having the sights aligned. There's also a front sight component to the sighting system.

Well,Ok, I'll agree the eye wants to center everything up looking through a rear peep sigh. And the eye can do a very good job of that.
I'll agree those come under the heading of "sight alignment"


But ti illustrate my point,if you unscrew the aperture from the receiver sight,and go full "ghost ring" you will at least have the opportunity to look through the sight window with less precision of sight alignment.

You can use the sight with some error of eyeball alignment,and it will show up on the target.

As I nderstand it,we get parallax error shooting with a scope for the same reason.

I also understand that focusing the ocular lense and the parallax adjustment of the scope,we can minimize the error,just as we can screw a smaller aperture in a receiver sight

Positioning of the eyeball is an important factor. A repeatable spot weld contributes to success.

Which is one reason why ,IMO, without the correct stock geometry,tall rings,56 mm objectives or the old tunnel see thru rings lift the face off the comb. Its harder to find a repeatable spot weld with your chin

 

[Bart B.]

As long as you pay attention to the alignment of both of the sights (front and rear) any significant issues with eye positioning will immediately result in visible misalignment of the sights with each other.

How much is signficant?

Wouldn't zero be better?

How much is the minimum angular resolution in MOA for the eye? 1/16th, 1/8th, 3/4th? More?

Just because you cannot see it doesn't mean it's zero. It's not the same for all of us. We all cannot resolve the smallest letters on an eye chart. Depending on the test and image contrast, it varies.

The decision of scope sight companies and others renaming target or range focus to parallax adjustment has caused more problems in communication and understanding how sights work.

 

[Bart B.]

I'm asking a question,rather than making a claim.

Correct me if I'm wrong,but with a scope,when you look through the "window" of the scope,ideally you sighted in with a spot weld that positions your eye centered consistently behind the scope.

If you move your eye slightly off center,your scope "window" may be forgiving enough you still see full field,but the apparent position of the reticle on the target may move.Obviously if the reticle is then moved to target,some error maybe introduced to the point of impact.

So,thats one somewhat reasonable,if imperfect (perhaps) explaination of how we see parallax through a scope.

My question: How is it that much different when I look through a peep sight?

I'm looking through a window.Ideally ,my eye will want to center in that window. Ideally,my spot weld is set up so my eye will center consistently.

If I move my eye around,I can still see through the peep,but my shots will show error on the target

What is the difference? Why wouldn't we call both parallax?

Slightly off topic,I believe a few years back,it may have been Bart B who suggested if your spot weld is good and consistent you can remove your rear sight and shoot surprisingly well.

The diameter of the peep orifice is merely a boundary to ensure your eye is centered where it is supposed to be.A very good spot weld technique can repeat pretty well.

That said ,good,consistent spot weld helps parallax,....True?

HiBC understands, explains and posted all the right stuff. The eye to target aimpoint axis must be on the front to rear sight axis. Any angle off changes the LOF to LOS angle and direction the same amount.

Parallax happens with all sights. Even shotguns shooting skeet or trap where a good, consistent spot weld helps when there's only one bead on the rib at the muzzle.

 

[zukiphile]

That said,good,consistent spot weld helps counteract parallax,....True?

Since a parallax error doesn't arise in an optic unless the viewer has occupied two different positions vis a vis the scope, a weld that reduces any variation in position will reduce parallax error. I've gotten good accuracy from some cheap scopes just by using a stock that fits well.

If you move your eye slightly off center,your scope "window" may be forgiving enough you still see full field,but the apparent position of the reticle on the target may move.Obviously if the reticle is then moved to target,some error maybe introduced to the point of impact.

It's important to state why the reticle moves relative to the target; they aren't on the same plane because they are focused at different distances. That's why parallax gives rise to an error in an optic and why eliminating that difference eliminates the error.

My question: How is it that much different when I look through a peep sight?

Parallax is present whenever a viewer moves relative to two objects that are at different distances, whether those two objects are the image of a reticle and that of a target, or a rear sight and front post, or a front post and target.

With iron sights, moving the front or rear sight out of alignment with the target doesn't introduce a parallax error because it isn't an error at all. Instead, it is an apparent and faithful representation of poor alignment.

 

[JohnKSa]

The eye to target aimpoint axis must be on the front to rear sight axis.

Of course. If the eye is off axis with metallic sights, the sights will show misalignment. If the sights appear to be misaligned, one can expect that the aimpoint will not correspond to the impact point.