Parallax.... how to?

[Crews]

So I get the concept behind parallax..... if you're looking at the speedometer from the passenger seat the needle looks like it's in a different spot that what it is from directly in front of it in the driver's seat. And I hear folks talking about how this may make your reticle tell you you're aiming at stuff that you're not. What I don't really understand is how to make sure I'm not DOING it.

How do you figure out if you are making an aiming error due to parallax issues? I've got an ATACR, and played with the adjustment when I'm shooting out at distance... often times there isn't a real huge discernible difference in the reticle clarity from one end of the adjustment to the other. I can see clearly and hit the plate, and I figure if there's a discrepancy in my POI it's probably just me needing to work harder on my fundamentals and trigger control. Is it as easy as turning the knob until the target is in the best focus for my eyeballs and rolling with it? Is there something in my sight picture that I should be looking out for that indicates there is an error?

 

[Sheldon N]

Is it as easy as turning the knob until the target is in the best focus for my eyeballs and rolling with it? Is there something in my sight picture that I should be looking out for that indicates there is an error?

Generally dialing for focus works.

If you want to test for perfect parallax, place the rifle in a position where it has the crosshairs on target and is stable without you holding or touching it. Then hovering over the cheek piece look through the scope (again not touching the rifle) and move your eye around. If you can see the reticle move around on the target then you have parallax error.

It's more sensitive and prone to error at closer distances. Out far it's not nearly as much of an issue.

 

[phlegm]

 

[47guy]

Generally dialing for focus works.

If you want to test for perfect parallax, place the rifle in a position where it has the crosshairs on target and is stable without you holding or touching it. Then hovering over the cheek piece look through the scope (again not touching the rifle) and move your eye around. If you can see the reticle move around on the target then you have parallax error.

It's more sensitive and prone to error at closer distances. Out far it's not nearly as much of an issue.

This right here.^^^

 

[308pirate]

often times there isn't a real huge discernible difference in the reticle clarity from one end of the adjustment to the other.

That's because parallax adjustment has nothing to do with reticle FOCUS (clarity and focus are not the same thing). Parallax adjustment has everything to do with bringing the target image into focus (technically bringing the target into the same focal plane as the reticle).

Reticle is focused to your particular eye using the occular's diopter adjustment. The target is focused using the parallax knob. Rough adjustment by watching the target come into focus, fine adjustment as Sheldon N described.

 

[Crews]

Okay, thanks for the input guys. The take away for me is to first go focus the reticle for me using the diopter adjustment. Then make sure I’m at least getting the best focus I can with the knob. If I want to verify leave the rifle stationary and move my head a little bit to see if the reticle moves around.

 

[Racer88]

I get the concept of parallax. I also understand adjusting the diopter is to get the reticle in focus, parallax knob focuses the target image. I'm also familiar with the technique of moving your head slightly to see if there is any movement of the reticle relative to the target to confirm parallax-free.

Here's my question: I find that the distance markings on the parallax know rarely / never coincide with the measured target distance when ideally focused. Especially at the longer distances... say 300+ yards... once I have the target sharply focused, the knob is closer to the "infinity" end, past the indicated distance number on the knob.

Can I safely assume that the distance markings on the parallax knob effectively mean nothing? Pay no attention to them?

Thanks!

 

[KML7201]

I get the concept of parallax. I also understand adjusting the diopter is to get the reticle in focus, parallax knob focuses the target image. I'm also familiar with the technique of moving your head slightly to see if there is any movement of the reticle relative to the target to confirm parallax-free.

Here's my question: I find that the distance markings on the parallax know rarely / never coincide with the measured target distance when ideally focused. Especially at the longer distances... say 300+ yards... once I have the target sharply focused, the knob is closer to the "infinity" end, past the indicated distance number on the knob.

Can I safely assume that the distance markings on the parallax knob effectively mean nothing? Pay no attention to them?

Thanks!

Yes, ignore the markings. Just turn the knob to focus the target.

 

[Dthomas3523]

I get the concept of parallax. I also understand adjusting the diopter is to get the reticle in focus, parallax knob focuses the target image. I'm also familiar with the technique of moving your head slightly to see if there is any movement of the reticle relative to the target to confirm parallax-free.

Here's my question: I find that the distance markings on the parallax know rarely / never coincide with the measured target distance when ideally focused. Especially at the longer distances... say 300+ yards... once I have the target sharply focused, the knob is closer to the "infinity" end, past the indicated distance number on the knob.

Can I safely assume that the distance markings on the parallax knob effectively mean nothing? Pay no attention to them?

Thanks!

If the markings on your particular optic don’t line up, just learn where the line up for common distances. This helps a bit to set before you shoot a stage.

Sometimes the markings are close and sometimes not. This is why some brands such as TT do not out distance markings on their parallax knob.

 

[perttime]

...
It's more sensitive and prone to error at closer distances. Out far it's not nearly as much of an issue.

I believe people who do Airgun Field Target competition use parallax to estimate distance to target. Distances are very short by centerfire rifle standards, so parallax errors are not hard to see. Turn your focus/parallax wheel until there is no error, note the indicated distance, and set your elevation knob accordingly.

 

[MarkLeupold]

Okay, thanks for the input guys. The take away for me is to first go focus the reticle for me using the diopter adjustment. Then make sure I’m at least getting the best focus I can with the knob. If I want to verify leave the rifle stationary and move my head a little bit to see if the reticle moves around.

One other thing. If you have a FFP reticle, focus the diopter with the parallax on the infinity setting. Some people forget this step.

 

[davsco]

One other thing. If you have a FFP reticle, focus the diopter with the parallax on the infinity setting. Some people forget this step.

didn't forget that because i didn't know that! what's the rule if any for sfp? thanks!

 

[Diver160651]

Like a lot of guys in here I have had way to many nice scopes and brands to list. Of all my scopes, the ATCAR 5-25 (a great scope) had one of the worst yardage markings of those that had them. Hence NF argument against them for years.

Some scopes seem more prone to conditions messing with the actual location required for the knob.

 

[MarkLeupold]

didn't forget that because i didn't know that! what's the rule if any for sfp? thanks!

I don't think second focal plane has a rule to it regarding parallax because of the physical position of the reticle inside the scope

 

[RTH1800]

To further confuse you, the point of maximum optical clarity does not always coincide with minimum parallax.
To field check simply move your head with rifle on bipod or tight sling etc.
Some scopes will adjust for clarity but parallax does not change.

 

[Diver160651]

Also why old school - scope shadowing, really is still a useful skill

 

[Vandy321]

Sorry to bump a thread dead for a year, but....

How parrallax error is normal/acceptable?

I've got a S&B 5-25...at 600 yards, I get about .5 mil movement in the crosshairs when I beleive I have parralax set, seems to get slightly better on infinity, maybe .25 mil, but I cant seem to find a setting to where the vertical stays firmly put as I move my nugget around the eye box

 

[Dthomas3523]

Sorry to bump a thread dead for a year, but....

How parrallax error is normal/acceptable?

I've got a S&B 5-25...at 600 yards, I get about .5 mil movement in the crosshairs when I beleive I have parralax set, seems to get slightly better on infinity, maybe .25 mil, but I cant seem to find a setting to where the vertical stays firmly put as I move my nugget around the eye box

Zero parallax is the only amount that’s acceptable.

 

[47guy]

Is the gun absolutely solid? Not moving with your head? If yes the parallax May be out of adjustment or broken.

I had a minox that did this and turns out the parallax was broken.

 

[Vandy321]

It should be solid, hands off...I'll throw it on the bench tomorrow to double check.

When trying to find that sweet spot, is it best to slowly adjust in from infinity in 5ord increments or so, go hands off each time and check?

Is there a fast/better way to set it. Target will focus, but my eyes, which are pretty good, when it does focus, the true parallax seems a bit off.

 

[47guy]

Do you ware glasses

 

[Vandy321]

Do you ware glasses

No, 20/17 in both eyes, no shooting glasses, no see through lens covers or anything either, just mk1 eyeball and glass

 

[47guy]

Gotcha just trying to rule stuff out

 

[Vandy321]

Not discounting a broken or out of adjustment parralax, but it does move, feels like it anyhow, I can see target focus come and go, etc. Wouldn't expect a undropped Schmidt to have issues, but if I cant figure ut out, maybe I'll send it in after hunting season just to be sure.

 

[Sheldon N]

I've got a S&B 5-25...at 600 yards, I get about .5 mil movement in the crosshairs when I beleive I have parralax set, seems to get slightly better on infinity, maybe .25 mil, but I cant seem to find a setting to where the vertical stays firmly put as I move my nugget around the eye box

My guess is you are bumping the gun or causing movement. The only way I can get 0.5 mil of vertical from my S&B 5-25 is to do something drastic like a target at 50 yards and parallax defocused to 300+ yards where the image is super blurry and I can't really see the target anymore.

For more distant targets 150+ yards I physically cannot get 0.5 mil of vertical movement on parallax. I have to focus close to the point where I can no longer see the image before I get 0.5 mil. Most I can get is about 0.2 mil while still keeping the target visibly focused in the scope. And I have to try to get that much. This is all with a gun locked in a tripod not touching it.

FWIW when I shoot PRS stages with targets from 300 to 1000 I don't usually adjust parallax. Split the difference, set it around 500 and shoot the stage.

 

[Carl_Ross]

When I shoot PRS stages with targets from 300 to 1000 I don't usually adjust parallax. Split the difference, set it around 500 and shoot the stage.

Same here, I might touch my parallax mid-stage once every two to three matches, if that. That said, not all scopes are equally forgiving. Having tested a ATACR 7-35 (well known for forgiveness in this arena) vs my K525, the NF is definitely superior. Yet I don't feel the limited but larger variation in my Kahles almost ever costs me a shot.