Question About Adjustable Parallax Optics

[mallic]

Say you sight in the optic initially at 25 yards with the parallax setting to 25 for an on paper site in, how much if any would the POA move if I moved the target out to 100 and changed the parallax setting to 100? Was wondering if parallax setting could be adjusted in the field while hunting without rezeroing for best chance shots at various distances.

[Harrier]

I have heard of that happening with Objective based AO in the past, although I can't recall the last time I suspected it. I would imagine is more likely with cheaper scopes. What scope are you asking about.

It seems that when I sight in at 50yd I almost always have to make additional adjustment when moving to 100, and even a little more when going to 200. Coming the other way, 200 to 100 doesn't require that adjustment. 25 or 50yd is good to setup a scope and adjust your windage to get on the paper at 100, but I don't use it for anything else unless that is all the range I have and I am trying to set BSZ. Even then i would confirm at distance.

ETA, The meant to indicate the shortest distance I typically use to initially adjust a scope is 50yd. I don't use 25yd anymore unless for BSZ.

Like 444 mentions, I use the parallax adjustment mainly to focus the target between ranges- until its in focus I can't tell where the reticle is on the target... but if the POA were to change due to the focus adjustment, then the POI would probably also change, but like I said, that shouldn't happen with a decent optic. These days I try to buy side focus scopes as reaching forward to turn the objective is a PITA.

[mallic]

I just used 25 as an example for the sake of what most people start working their zero out on. Real world example would have been more like 100 to 300. Planning on using this rifle to hunt and if adjusting parallax doesn't tend to shift zero, I figured I would zero it at a known distance with a known parallax setting and adjust it in the field to what the shot requires. I understand that parallax isn't an issue if you maintain the same cheek weld and eye to eyebox position 100% of the time, but I know for a fact that I will fail to do so.


Optic I am interested in trying is https://www.primaryarms.com/primary-arm ... oa-reticle

[samnev]

I initially zero all my rifles in at 25 yards. I only have a few scopes that allow me to set parallax correctly at 25 yards and zero my scopes 1.25" high which get me close for my 100 yard adjustments. Those that do I have reset the parallax at 100 yards and always have to readjust the turrets in both windage and elevation once again 1.25 inches high. My range only goes to 200 yards. When I do shoot to 200 yards I usually have to reset the parallax slighly for a sharper image. But the my poi seems to be right on.

[shooter444]

I find it interest how PARALLAX is defined and used by so many different shooters.

First, I have been taught PARALLAX does not affect Point of Impact/zero. PARALLAX only affects cross hair position on target,( AKA POA, Point of Aim ), by basically correcting cross hair movement/mirage caused by scope lens position at certain power settings and shooting distance.

I have been taught that PARALLAX primarily comes into play when using high power settings at long distances. In this scenario, parallax can affect the position of the cross hairs (POA) when eye position behind the scope changes.

PARALLAX is basically a lens/focus created VISUAL ABERRATION,... your weapon will not change POI/ZERO just because you move your eye position enough to cause PARALLAX AFFECT (POA) on the cross hairs. BUT, if you do not allow for PARALLAX, at high power settings, and at long distances,... you can miss your target.

Only weapon, action, caliber, loading, shooter, etc., can affect Point Of Impact.

This is what I was taught,... your lessons may differ.

As I said, I have learned over the years, that PARALLAX is only an issue with scope power of 10X and more. So, the OP's perspective purchase of a 14X maximum power adjusting scope probably could get by at distances less than 200 yards, with just using PARALLAX ADJUSTMENT as a FOCUS type adjustments. I use the term "FOCUS TYPE PARALLAX ADJUSTMENT", because basically, that is about as technical as I usually get when shooting at less than 300 yards, at least this is how I approach it,... your mileage may differ.

Remember, PARALLAX only affects cross hair position on target (POA),... NOT (POI) POINT OF IMPACT/ZERO. Your rifle's POI will remain the same with, or, without a scope.

As I said, this is what I have been taught.

Right or wrong?

You decide!

[Delfuego]

mallic: What scope do you own? Many scopes cannot focus down as close as 25y. Some may say they do, but may not. Some lower end scope can be more susceptible to parallax in their design and material. More importantly the focus/parallax number on the scope knob are nonsense and should not be trusted. Trust the image, trust the focus. Depending on the quality of your scope, the parallax may be very important. If your hunting and have the time, focus! Make sure your reticle is crisp, you can do this by aiming into a blue sky. Make sure your target is in focus, but if your scope can only achieve one, it needs to be the reticle. On rifles, you cheek position can also effect you POA/POI. If you have to crane your head (or move your head fore/aft) you can induce error. Ideally you should get the same image everytime you bring up the rifle. This can be addressed with gear (scope rings/cheek pad/etc) and practice.

shooter444: Parallax can occur with 1x red dot if not built properly. A lot of the old cheap red dot sights suffered from this. Parallax (and mirage) will essentially change your impact by fooling your eyes. The POI is the same, but your POA will vary because you cannot really predict and effectively compensated for parallax. You will simply shoot where the crosshairs or dot is, that's your brain at work.

[mallic]

mallic: What scope do you own? Many scopes cannot focus down as close as 25y. Some may say they do, but may not. Some lower end scope can be more susceptible to parallax in their design and material. More importantly the focus/parallax number on the scope knob are nonsense and should not be trusted. Trust the image, trust the focus. Depending on the quality of your scope, the parallax may be very important. If your hunting and have the time, focus! Make sure your reticle is crisp, you can do this by aiming into a blue sky. Make sure your target is in focus, but if your scope can only achieve one, it needs to be the reticle. On rifles, you cheek position can also effect you POA/POI. If you have to crane your head (or move your head fore/aft) you can induce error. Ideally you should get the same image everytime you bring up the rifle. This can be addressed with gear (scope rings/cheek pad/etc) and practice.

Posted it earlier, but I am thinking about buying this one: https://www.primaryarms.com/primary-arm ... oa-reticle

I don't currently have an optic on this rifle.

[Harrier]

That's a hellova price for a FFP, Illuminated 4-14 scope!
Also I notice it is a side focus which are way way better that the front AO adjusters I thought you were talking about. Although I don't have a Primary Arms scope, I have heard a lot of good about them. I'm not sure about this particular model but some of them are made in China so I would search around to find out about the glass quality.

[Harrier]

That's a hellova price for a FFP, Illuminated 4-14 scope!
Also I notice it is a side focus which are way way better that the front AO adjusters I thought you were talking about. Although I don't have a Primary Arms scope, I have heard a lot of good about them. I'm not sure about this particular model but some of them are made in China so I would search around to find out about the glass quality. An alternative for comparison might be the New 4-16x44 Vortex Diamondback Tactical FFP with EBR-2C reticle... It would give you 85 MOA adjustment instead of 60 and a lifetime warranty instead of 3 yrs. OTOH it is about $50 more. I read it's also made in the Philippines (a step up... as most say).

[mallic]

That's a hellova price for a FFP, Illuminated 4-14 scope!
Also I notice it is a side focus which are way way better that the front AO adjusters I thought you were talking about. Although I don't have a Primary Arms scope, I have heard a lot of good about them. I'm not sure about this particular model but some of them are made in China so I would search around to find out about the glass quality. An alternative for comparison might be the New 4-16x44 Vortex Diamondback Tactical FFP with EBR-2C reticle... It would give you 85 MOA adjustment instead of 60 and a lifetime warranty instead of 3 yrs. OTOH it is about $50 more. I read it's also made in the Philippines (a step up... as most say).

Eh I like illuminated reticles and honestly won't need the extra adjustment. And I am not really concerned with the 3 yr warranty. If it lasts three years at that price, it has paid for itself. And yea what drew me was a cheap as hell FFP optic to play around with that doesn't have any pre-ranged BDC features.

This is going on a 16 inch AR10 which will be used for plinking in the desert and the occasional hunting trip.

[Delfuego]

When it comes to scopes, you get what you pay for. That PA scope might be a pretty good scope, but rest assured it is made from low-end components in china. The owner of Primary Arms is a super nice guy and good on service and support, but you might want to spend a little more and get a little more. There are a lot of new scopes that check all the right boxes, but fail to deliver. If you're just putting it on an 223 AR for plinking it will probably be fine. However if you are hunting, shooting longer ranges or shooting a heavy caliber you are asking for trouble.

I would look at the SWFA 3-15, Vortex PST (Gen1/2), Sig, Athlon Ares or even the new Nikon Black. The first 2 are proven performers the Nikon looks promising. There are lots of good mid-range scopes around now. Most of these scopes will likely come from the Philippines, the higher-end scopes from the same companies (Primary Arms included) will come from Japan (Light Optical Works Factory). You might also look for something used for a discount.

I am kind of a scope snob, so take what I say with a grain of salt. I have however owned and played with a lot of scopes.

[shooter444]

For me, this is the primary absolute truth and reality when scoping a weapon!!!


"When it comes to scopes, you get what you pay for. "

BUT,... the second most absolute truth when scoping a weapon is,...

Do you know what your needs in a scope really are, before you pay!

I don't have a spotter to zero me in on 1.000 plus yard targets! I don't need a high dollar scope to shoot at less than 300 yards,.... which is the limit of my personal shooting!

Over the years, I have succumb to my never ending quest for the cheap, but good, holy grail rifle scope, many times. And, I have been sadly disappointed, 90% of the time.

But,... and this is a BIG BUT,... in all those failures over many years, to find a good cheap scope, I spent far less than half of what a prime top tier scope would have cost me.

Was it worth it,... probably not for most, who have something better to do! Especially when wasted cash, wasted time, wasted ammunition,... is all figured in!

But, after many years of trials and tribulations,... there can be a worth while cheap scope to be had at the end of the rainbow!!! In fact! I found my best cheap scope company some years ago, and the two I bought are still functioning as correctly, as day one!

I got what I payed for, in these scopes,.... and I didn't have to pay an arm and a leg,... not even a finger, or, a toe!!!

[Delfuego]

On Sale. Ready to mount. Done.

https://swfa.com/swfa-ss-3-15x42-tactic ... o-kit.html

[shooter444]

Or, you could go the way I did,... can't promise any results,... but, like I posted, I have no complaints for all the years I have had two!

And,with a savings of almost $300 on a scope with the same power range, side parallax adjustment, inside the scope bubble level, illuminated etched reticle, but, with a 52mm objective lens and a limited lifetime warranty,..., you may be tempted as well!

http://www.konus.com/us/Catalogue/Hunti ... flescopes/

http://www.konus.com/us/Catalogue/Hunti ... 0-4-16x52/

http://www.opticsagent.com/KONUS-4X-16X ... ZwQAvD_BwE

And,you can get free shipping from Amazon Prime,...

[Harrier]

I've a Konus Pro 3-12x50 for a few years now. It is an older model with front AO focus and its been on various rifles but is temporarily on an AR. It's been a decent scope for everything I've used it for (mostly 200--300 yds) and I haven't had any problems with it. It tracks good and holds zero. It will probably go back on a hunting rifle as it has the standard a plex reticle with no ranging hash-marks, so its more suited to hunting use.