Parallax shift

[BoydAllen]

Putting it another way, if your objective (or side) focus is set for absolutely the sharpest target image that you can get, and you have parallax, your eyepiece is slightly out of adjustment.

 

[Texas10]

I'm going to have to go back and adjust the eyepiece on my scopes now

Not trying to hijack the thread, but I have a question about side focus adjustments. I shoot targets that are the dayglo orange dots on white paper and I notice that when using the side focus that the dots go from burnt orange to dayglo depending upon where I set the side focus. I presume this is chromatic aberration but what is it telling me about my focus, or my scope for that matter?

 

[Texas10]

As hard as it is for me to agree or support anything that flaming idiot writes, this is probably true. There's a reason he "don't come around anymore"...he cant. Or at least he is not supposed to. That jacka$$ has been banned from just about every forum on the web. He will still try though. Just cannot help it, he shows up about every 4-6 months or so with a new username. I think they figure him out {it aint hard} and once again get rid of him. His number one claim to fame is that he "wrote the third most important paper on eyeglass repair".
Here is a quick way to check out really having vertical and no horizontal {or the other way around??}...Look thru the scope and identify which it is, then turn the entire rifle 90 degrees and try again to see if the parallax movement you are seeing changes to the opposite. If it is truly in the scope then it has to. If it remains horizontal with the rifle turned then it has to be something you are doing.
Parallax error {that movement you see} occurs when the reticle is not on the same focal plane as the rest of the scope. Many scopes have a separate focus at the eyepiece. This sometimes has a pretty wide range in which the reticle can appear in focus. It still has to be correct {in the right place} or the side or objective focus may appear fuzzy when parallax is gone.
I also hate posting on optics questions because it seems like everyone has a different way of wording things optical. How easy or hard it is to adjust out parallax has a lot to do with the design and quality of the optic to begin with. One scope that stands out {probably because it was purpose designed this way} is the USMC Unertl 10X. Also known as the MST-100, initially it is a real pain to get focused, but once you have it there is no parallax over a very wide range. Of course it's a fixed power, so that helps a lot although when you compare it to the Leupold M1 Mark 4 {also a fixed 10X} with it's side focus that constantly needs cranked on to eliminate parallax error it shines.

OK, i get it, the guys prolly got a personality disorder or two, but in your opinion is his information correct for the most part? I found the article informative, and a bit overboard AUTHORITATIVE in the way it was written. He'll never make a good technical writer...LOL But for me it clarified the scopes inner workings a little. But it also leaves me with more questions than answers which I'll post about in another thread.

 

[msinc]

OK, i get it, the guys prolly got a personality disorder or two, but in your opinion is his information correct for the most part? I found the article informative, and a bit overboard AUTHORITATIVE in the way it was written. He'll never make a good technical writer...LOL But for me it clarified the scopes inner workings a little. But it also leaves me with more questions than answers which I'll post about in another thread.

Yeah, for the most part the moron wont really steer anyone wrong...he's just a professional jerk that cannot help himself. I don't know if he's bipolar or manic depressive or some other psychotic disorder, but he is something.
When you say it left you with more questions than answers...that's just the way he likes to bait people. It's important to understand how he works...he isn't trying to help or educate anyone...he's just looking for someone to pi$$ with. He writes purposely that way so someone will try and clarify and then it's on!!! The clown will pounce with both feet into a big argument in which he must win and generally wont quit until he is banned again. Even when you agree with the idiot he still argues.
Over on Predatormasters he actually had a coupe of guys that were in love with him. They tried to get him re-admitted several times but thankfully the owner said "I've had enough of him, no". Imagine what kind of galactic flaming AH you would have to be to actually re-register under a different username, just so you can get on here and pi$$ with everyone that will respond. Ridiculous!!!!! No matter how "correct" his information may be, it's difficult to take him serious...I think THAT is what hurts him the most.

 

[Don_Parsons]

You can keep shooting the optic lens the way you've been doing it all along,,, or you can adjust it so it benefits the down range horizontal & vertical.

Nothing like having Firearm, Ammo, optic Scope and Shooter all dialed in on a level playing field.

As some of us age, our eye sight changes, so fine tuning "might" need to be addressed once in a while.

These are the tools I bring to the range when setting up a optic that I choose to shoot long range.

1- A Blue Sky Day.
2- A coloured felt marker.
3- Good quality bypod.
4-Firm bunny ear rear bag.
5-Distance of 300 to 1700 meters or beyond.
6- Large targets with mileage bars.
7- And as much time needed to get things sorted.

Funny that we allow what ever time we need to get things right for long range shooting, yet "alot" of shooters don't take the time to fine-tune thier personal optic lens which can benefit us "More" then chasing smaller issues that benefit us the least.

Of course I only share Earl Hines concepts of "Parallax Adjustments" with those that choose to chase this part of the dragons-tail once and for all.

This is not saying that there aren't other ways to fine tune the optic scope as well.

https://www.longrangehunting.com/articles/what-is-parallax.1175/

Foot-note added:

1- I start at 300 to 400 meters since it allows me to see the cross-hairs move off target with rifle firmly planted.

2- If I don't see the cross-hairs move that much,,, then I manipulate the focus and parallax so I can move the cross-hairs to maximum amount.
This would be 12" to 17" inches from the target bulls-eyes out-ward to the edge of the target. Target placed at 3 to 400 meters.

3- I'll share more on this for those interested in getting this sorted,,, again,,, for those that choose to correct a optic lens for their own personal shooting needs.

PS: If a person chooses to shoot close range, is not fussy about spilling hairs at 25 feet to 200 meters,,, then carry on.

Those that choose to push the limits of 300 to infinity shooting meters "could" benefit from this.

I have 3 F Class optic scopes ready to go,,, and 1 for my 1700 meter stuff.
It's like a work of art sorting out the things that benefit us the most as we address the small things at a later date.

A proper tuned optic lens is a major thing in my shooting sports.

More wrong then right I hope. Ha

Don

 

[alinwa]

Yeah, for the most part the moron wont really steer anyone wrong...he's just a professional jerk that cannot help himself. I don't know if he's bipolar or manic depressive or some other psychotic disorder, but he is something.
When you say it left you with more questions than answers...that's just the way he likes to bait people. It's important to understand how he works...he isn't trying to help or educate anyone...he's just looking for someone to pi$$ with. He writes purposely that way so someone will try and clarify and then it's on!!! The clown will pounce with both feet into a big argument in which he must win and generally wont quit until he is banned again. Even when you agree with the idiot he still argues.
Over on Predatormasters he actually had a coupe of guys that were in love with him. They tried to get him re-admitted several times but thankfully the owner said "I've had enough of him, no". Imagine what kind of galactic flaming AH you would have to be to actually re-register under a different username, just so you can get on here and pi$$ with everyone that will respond. Ridiculous!!!!! No matter how "correct" his information may be, it's difficult to take him serious...I think THAT is what hurts him the most.

yeahhh.... I hear you..... that galactic asshole flaming moron jerk bipolar manic depressive idiot clown MUST come in just to bait people like you and "pi$$" in their cheerios......

you sure made that point clear

thankfully, due to yourself we'll never have to deal with HIM again! No more a' that "correct" information to deal with!!

wheewwww

Thank You So Much For Your Protection

 

[msinc]

.....thankfully, due to yourself we'll never have to deal with HIM again!.....

Due to myself???? No sir, you are wrong!!! I didn't ban him from MOST of the internet forums out there...he did, go and cry to your hero. Better yet, I understand he is now in Arizona...maybe you can fly out there and find him...maybe you two can get married. Even Coburn has followers, I guess you are one of them.

 

[Depart123]

Due to myself???? No sir, you are wrong!!! I didn't ban him from MOST of the internet forums out there...he did, go and cry to your hero. Better yet, I understand he is now in Arizona...maybe you can fly out there and find him...maybe you two can get married. Even Coburn has followers, I guess you are one of them.

Birds of a feather and all.....they might make a happy couple.

 

[Texas10]

Putting on my raincoat now..

 

[Texas10]

Seriously though, after reading all the info about how the ocular's sole purpose is to focus on the reticle, and how to focus it, this leaves me with more questions.
The procedure I keep reading is to point the scope at the sky or something far away and move your eye quickly onto and then off the reticle, so your eye doesn't have time to refocus. And turn the ocular until cross hairs are in focus without your eye having to adjust. HOWEVER, this assumes your eye is focused on something (infinite?) before hand. So what state of focus should your eye be when performing this task? If the sky is clear and without any clouds to focus on, how do you know it's focused properly?

Secondly, (again referring to the ocular's sole purpose) when shooting I read I should focus my eye on the reticle, not the object image in the scope. If both are on the same plane, i.e. properly adjusted, what difference does it make to focus on the cross hairs and not the object? If my eye has to refocus when shifting from object to reticle, does this indicate the scope is not properly adjusted. Or am I better advised to focus my attention on the reticle instead of the object?

Not being argumentative, just trying to get a good clear picture of what is obviously an important part of scope adjustment for long distance shooting. And my Vortex HS 6-24X50 is very hard to adjust so that both the object and reticule are properly focused and at the same time have no parallax errors.

 

[Don_Parsons]

How will you know if the objective eye peace is out of focus.

This will be easy to address.

Let's go to the 300 meter / yard target down range to find out how close you are at this point "after" you set the parallax to infinity and adjusted the optical eye peace lens till the cross hairs are crystal clear,,, using full zoom of course. {Blue Skies}

Plant the rifle solid, adjust the parallax so the target is clear,,, starting from the lowest setting up to where the 300 meter / yard target is clear.

Do the side to side / up & down bubble test.

If the cross-hairs stay on the target bulls-eyes with out moving a Inch,,, then your dialed in correctly,,, if the cross-hairs move 4", 6" on more inches off the bulls-eye,,, its now time to fine tune.

It is a bit challanging at first when getting the optic focus and parallax tuned,,, I got frustrated learning this,,, so I went to the other end of the of the scale by manipulating the cross-hairs to make the X drift off the target.

Once I learned where out of focus was,,, it made it easier to find / "get closer" to what focus is. LOL.

Like my Pops told me, tear things apart, then read the instructions. Ha

 

[Depart123]

Seriously though, after reading all the info about how the ocular's sole purpose is to focus on the reticle, and how to focus it, this leaves me with more questions.
The procedure I keep reading is to point the scope at the sky or something far away and move your eye quickly onto and then off the reticle, so your eye doesn't have time to refocus. And turn the ocular until cross hairs are in focus without your eye having to adjust. HOWEVER, this assumes your eye is focused on something (infinite?) before hand. So what state of focus should your eye be when performing this task? If the sky is clear and without any clouds to focus on, how do you know it's focused properly?

The idea of pointing it at the sky, or a white wall, or whatever, is to have a field of view devoid of other objects for your eye to focus on besides the reticle. The proper procedure is to actually close your eye to let it rest, then open it to look at the reticle.

 

[Kramerica]

Here is the response I got from the engineer...

Good morning Jalen,
OK, what you are seeing is caused by astigmatism, and will vary from user to user based on the amount of inherent astigmatism each person has. The main thing the optical engineer said was to minimize motion when checking for parallax. Another thing he mentioned was to hold the same gun mount position so it doesn't affect accuracy, meaning do the same thing every time you get on the gun. He also mentioned using the side to side motion while checking for parallax is more likely to move your eye out of alignment and be harder to actually get parallax free. I hope this helps. One last thing to check, I thought of something over the weekend, how old is that optic?

 

[BoydAllen]

If your scope is properly adjusted eye position should not be critical because the target image and the reticle will be in exactly the same plane, as if they were printed on the same sheet of paper. There is a lot of crap on the internet about this subject because people do not get that manufacturers are not writing instructions to the highest level, because that would confuse most of their customers. If your scope's eyepiece is properly adjusted, and your objective or side focus is set for peak target sharpness, you will not have parallax, eye position will not be critical and that eyepiece setting will be correct for all distances as long as the front of the scope is properly adjusted for peak target sharpness. The question that the "experts" do not answer is what to do when you have followed the basic instructions for setting your eyepiece and you cannot get zero parallax and peak target sharpness at the same setting. They simply ignore that situation and keep telling you that they are experts. I am not an optical engineer or expert, but I can teach you how to fix that situation. I usually do this by PM or phone because I am doing it to fix someone's problem not to argue.

 

[Brians356]

If your scope is properly adjusted eye position should not be critical because the target image and the reticle will be in exactly the same plane, as if they were printed on the same sheet of paper. There is a lot of crap on the internet about this subject because people do not get that manufacturers are not writing instructions to the highest level, because that would confuse most of their customers. If your scope's eyepiece is properly adjusted, and your objective or side focus is set for peak target sharpness, you will not have parallax, eye position will not be critical and that eyepiece setting will be correct for all distances as long as the front of the scope is properly adjusted for peak target sharpness. The question that the "experts" do not answer is what to do when you have followed the basic instructions for setting your eyepiece and you cannot get zero parallax and peak target sharpness at the same setting. They simply ignore that situation and keep telling you that they are experts. I am not an optical engineer or expert, but I can teach you how to fix that situation. I usually do this by PM or phone because I am doing it to fix someone's problem not to argue.

What he said.

I guess it's time to just, um, yeah ... go ahead and reprint in full my essay on scope adjustment.

To wit:

Scope manufacturers' instructions are woefully inadequate. WRT parallax error, they generally advise adjusting objective focus until the target image is sharp. However that requires that the ocular (eyepiece) is already focused on the reticle plane. And their procedure for focusing the ocular is itself dicey: "Point the scope at the blank sky, glance quickly at the reticle (don't stare at it!)", adjust focus, repeat, etc. You are required to fight you eye's innate ability to bring the reticle into focus over a very wide range of adjustment.

There's a more precise, comprehensive approach, based on first principles: The only condition under which parallax error will be zero and target image sharp is when both objective and ocular have been focused on the reticle plane.

The easiest way to adjust for both zero parallax error and sharp target/reticle focus (making no assumptions about the scope's adjustments whatsoever) is as follows:

1. Adjust objective (side focus or AO) for zero parallax error, i.e. no apparent reticle movement on target while moving your eye around behind the eyepiece. (Disregard target image sharpness or focus.) Now the objective is focused on the reticle.

2. Adjust ocular (eyepiece) for sharpest target image focus (and, coincidentally, reticle focus - since they are now in the same plane). This is much easier than focusing on the reticle alone with a bright blank background, but you should still glance at the image for short periods, and trust your eye's first impression, which will also avoid eye fatigue.

Usually, a second iteration of the above two steps pays dividends in fine adjustment, since detecting parallax error (reticle movement on target) is easier once the image is more sharply focused.

Once you get the eyepiece focused on the reticle plane, and locked, thereafter focusing the target image for sharpness should also minimize parallax error, but I never trust that on the bench when accuracy testing - I always move my eye around behind the ocular to make darned sure there is no parallax error.
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