Advanced Marksmanship Management of Parallax Adjustment

[servicepuke]

Greetings!
My name is Kev.
I am using a Swarovski 4-12 scope now with fixed parallax set at about 100 yards (I think it is set at 115 yards.)
I am considering getting a scope with more magnification and elevation adjustment.
These scopes have adjustable parallax.
I primarily use this on my Remington 308 varmint for hunting.
How do you manage the adjustment of parallax when time is critical?
I know that many of you use first focal plane scopes for moving targets because you can judge range quickly on multiple moving targets at multiple ranges-how does the parallax adjustment fit in?
Thanks!
Kev

 

[BOLTRIPPER]

Re: Management of Parallax Adjustment

its easy...one very deftly twists the parallax nobbie if you need to...and then slap the boolit launching lever

 

[JoeSmith]

Re: Management of Parallax Adjustment

Depending on how your eye works, you may be able to set it at, say, infinity, and that might work for you. However, you will have to shoot it out to various ranges to find out if that will get you the accuracy you are needing.
Or you could preset it at 200 or 300 and that might cover enough range to get you close for quick shots.
That works for some guys I know, not so much for others.
The advantage of, say, the Schmidt and Bender designs, is that the distance setting on the parallax knob gives you a very quick head start on fine tuning the adjustment, ie, if you have a 550m target you can dial 500 quick and go from there. This compares to a lesser design like the "Bubble dots" on the Leupold. You have to memorize thru trial and right down the correct dot for a given range-why don't they just right the darn range corresponding to a given distance?

 

[servicepuke]

Re: Management of Parallax Adjustment

Thank you Shooter 5,
I was wondering how much leeway there is in focus (fuzziness) when the parallax adjustment is off by 200 yards or so.
The only scope I have with parallax adjustment is a cheapie and I'm sure it is not a good representation of the concept.
Deer lungs are a pretty good sized target so I doubt that the point of impact error would be a problem.
They seem to pop in and out of concealment at widely varying ranges and just give enough time for identification and aiming-I can't get them to pose while I make adjustments.
Thanks,
Kev

 

[Downzero]

Re: Management of Parallax Adjustment

You are not adjusting out the fuzzyness so much as the error. It makes quite difference in the focus but i highly doubt it'd affect accuracy to have your parallax adjustment off even by quite a bit, assuming you maintained perfect cheek weld and didn't introduce actual parallax error.

 

[BOLTRIPPER]

Re: Management of Parallax Adjustment

i sense a lot of BENCH SHOOTERS !!!!!!


how about managing or trying to figure out which way the wind blows...........there is one parallax adjustment.

then there is a consistent cheek weld as mentioned above.....yet another parallax procedure.....

and then there is the use it if you need it feature for them fading light scenarios or night shots.......

 

[Greg Langelius *]

Re: Management of Parallax Adjustment

Parallax originates from optical components and their alignment relative to the scope optical axis and the eye's pupil. This may be something of an oversimplification, but it explains the process well enough for this purpose. The closer the eye is to perfect alignment with the optical axis, the less parallax affects POI.

It's my belief that parallax is not well understood by many shooters, and that this lack of understanding is at the origin of most 'near misses'.

There is a technique called 'quartering the reticle', which finds better pupil alignment.

With scope ontarget, slightly nod and wag the head slowly and deliberately behind the scope eyepiece. As the pupil approaches the edge of the image, shadowing will appear along the image's edge.

While you're doing this, there may be apparent motion relative to the reticle and target. If this motion is present, it betrays a parallax miscorrection. If you can adjust the objective to reduce or eliminate this apparent relative motion, you have correctly compensated the parallax mismatch. If you can't, don't be discouraged, the next step will help.

Repositioning the pupil up/down/left/right behind the eyepiece to the point most closely centered between the shadow edges will place the pupil in a better position, where parallax, if present, will have less effect.

This location represents a more ideal cheek weld location. If the stock needs alteration to provide completely relaxed support with this alignment, this is the goal those alterations are aiming for.

Do this Quartering technique for each shot, so proper pupil alignment is a conscious and precisely repeatable thing, rather than a fortunate accident.

Greg

 

[servicepuke]

Re: Management of Parallax Adjustment

Thanks for the useful info.
I am always working on getting better at judging the wind.
Since my existing scope doesn't have parallax adjustment I have worked hard at cheek weld.
I will try the quartering method.
My main concern with an adjustable parallax scope is the ability to see and hit my target when there is not time for adjustment-they don't give me time for adjusting maginification either...
I guess I need to try look through a higher quality scope that has parallax adjustment and see if it fits my needs, or, if I need to stay where I am.
My hunting ranges stay well under 500 yards, so it would be more of a range toy (that I think I want) than something I need.
Thanks,
Kev

 

[sled_mack]

Re: Management of Parallax Adjustment

OK, I'm still pretty new to all this and a bit confused by the parallax issue.

I've been told that once the eyepiece is focused, I should not need to adjust the parallax knob for focus. Is this correct?

My scope is a Falcon Menace 4.5 - 18x. No matter what I do with the eye piece focus, I have to adjust the parallax knob to get in focus at different ranges. If the answer to the question above is yes, then I think I have a problem with my scope? Or is it just the higher end scopes that maintain focus at different ranges without adjusting the parallax?

Thanks for any input.

Steve

 

[TiroFijo]

Re: Management of Parallax Adjustment

You adjust the reticle sharpness with the eyepiece, an once done is set there for that particular user, at any range.

Yo adjust the focus of the viewed object and also take out parallax error with the parallax adjustment. Of course you have to adjust it at different ranges, this is perfectly normal.

The parallax error and even the object image being slightly off won't make for a large error if you have your eye well aligned with the scope, as described by Greg. It is nice to have the option to correct it, but there are more important things as boltripper said.

 

[Greg Langelius *]

Re: Management of Parallax Adjustment

Sled;

Scopes that employ adjustable objective (front) lenses take advantage of the fact that distance focus and parallax are related (but not the same thing). They construct the scope so parallax compensation gets adjusted with the same motion as adjusting the focus.

However, it's sometimes improperly linked, so when the focus is good (which is obvious when seen through the eyepiece) the parallax may not be (and unless you do the nod/wag thingie, that's not so obvious). Unfortunately, this improper linkage is rather common, especially among the less expensive scopes. Proper linkage is something you're paying for when you buy the more expensive scopes, and even if they're good, you still may not have the focus right on the button, so always nod/wag before that match shot, just to be sure. A few of the more expensive scopes provide a separate parallax adjusting knob.

Parallax is something that must be adjusted every time the focus is adjusted, which is why they link the adjustments.

However, if parallax is important to you, and the linkage is not correct, you may find yourself having to choose between good parallax adjustment and good focus. If parallax is secondary to a sharp image (as in hunting), favor the focus. If precise POI management is primary (as in match shooting), favor the parallax.

Scopes that do not allow focus/parallax adjustment are typically focused at infinity, and corrected for parallax to an arbitrary distance that corresponds to the most likely (in their opinion) distance for the average hunting shot, typically either 100 or 200 yards/meters, usually 200 for hunting scopes. They sacrifice shorter distance correction (where actual error is small) for longer distance correction (where error is greater, but parallax changes less as distances recede) Please note that while parallax is less obvious at lesser magnifications, it is still there in all its magnitude and glory. Parallax is something that increases like MOA (1" at 100yd becomes 2" at 200yd, and 3" at 300yd, etc.)

Boltripper is absolutely correct in assigning parallax a lesser importance for nearly all practical applications. For match shooting at small targets, though, I believe it takes on somewhat more importance.

Greg

 

[Unsichtbar]

Re: Management of Parallax Adjustment

Greg, best explanation of parallax that I have ever read, I have S &B scopes with both a parallax adjustment and with ( it set at 300 yds ). I have heard a case made for the benefits derived by having an adjustable parallax adjustment on a scope, also a case made for not having an adjustable one, for tactical application. Since my application is a tactical one, I think I prefer the fixed parallax scopes because the adjustable scopes ( have be adjusted and seem to have a narrow depth of field) something else to deal with. It don’t think I have missed a target (humanoid or silhouette) under 300 Yds due to parallax error with a fixed scope.


Question, over 300 yards say out to 1000 yards (tactical target) with a fixed parallax scope, sight picture full with no shadowing is there anyway to approximate what could be the potential error.

 

[Lowlight]

Re: Management of Parallax Adjustment

Cheek weld is what corrects uncorrected parallax... if you have a proper and consistent cheek weld you reduce the potential error caused by uncorrected parallax, it's why it's more important with Iron Sights, because it changes your perspective of Aim as Sterling puts it.

 

[Downzero]

Re: Management of Parallax Adjustment

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Cheek weld is what corrects uncorrected parallax... if you have a proper and consistent cheek weld you reduce the potential error caused by uncorrected parallax, it's why it's more important with Iron Sights, because it changes your perspective of Aim as Sterling puts it. </div></div>

This is exactly what i was trying to say.

Nose to the charging handle, Privates!

 

[sobrbiker883]

Re: Management of Parallax Adjustment

On an adjustable objective, mechanically the parallax is adjusted out when the focus of the target and the reticle meet, BUT the point that is set at is also with the diopter (reticle focus)set to 0.
When I have my general purpose sunglasses on that have my prescription for distance vision, the two don't necessarily match-if my sight picture if sharply focused, I can usually discern some parallax using the "quartering" method Greg described, because I need to adjust the diopter for the reticle to be clear.
I recently had a pair of shooting sunglasses made that have my near vision prescription in my scope eye, and my far vision Rx in my left. These work with the diopter set at "0", and the focus and parallax free image are back at the same place.

 

[servicepuke]

Re: Management of Parallax Adjustment

sobrbiker883,
Interesting idea on your glasses.
My Trifocals are becoming an issue with my shooting-more with iron sights, I usually remove them for shooting with a scope.
I am thinking of getting some prescription glasses made that focus at the distance to the front sight on my m1A.

 

[raptorfendercash]

Re: Management of Parallax Adjustment

try pulling your eye away from the scope until the view starts to close down leaving a black ring and center that ring in the scope each shot.this way you know your in the same spot each time.not that you would want to shoot like that all the time because you would not but it may show you if you are getting parallax error by shooting a couple groups both ways.