Others Can You Fix Out of Focus Parallax Correction

[Billm]

I had difficulty with the title of this thread, so let me clarify. In my years of hunting, scopes with parallax focus/correction were usually called Varmint scopes from the likes of Burris. As much as I wanted to, varmint hunting wasn’t really an option in Florida. I usually zeroed in my rifles at 100yd for a Maximum Point Blank Range of about 300yds. That’s all I needed for deer hunting. The last time that I was really into airguns I shot mostly with open or match aperture sights. So now that I’m “slightly” interested in PCPs and have bought a couple of side focus FFP scopes I’ve ran into an issue. The brand of the scopes doesn’t really matter at this point. One is a 5-25x56 with Japanese glass, the other is a 5-30x56 not Japanese glass. Both are FFP and focus down to 25yds - more like 27 yds. I don’t care if the range matched the actual range because I don’t use focus for range finding. I’ve been focusing the ocular for the reticle and then using the side focus to bring the target into the best focus. I’ve been switching back and forth between using a squeeze bag and a mechanical rear rest. I noticed that when focused there is a lot of parallax error. So, I researched it and either read a post or saw a video where someone mentioned that it is not unusual to have to have the side focus out of focus to actually eliminate the parallax error. That is actually what I have to do with both of these scopes to get the best parallax correction. I tried playing with the ocular focus, but it didn’t help. Is this something I just have to accept or is there a fix for this? Besides replacing the scopes. For pestling a little bit of parallax error wouldn’t bother me, but for 50-100yd benchrest I’d think it’s a factor. I’ve been shooting with it out of focus and that’s difficult with a tiny target lol. Yes, my post could be a little briefer, but I really like this forum and brevity doesn’t help with SEO lol.

 

[Solo1]

i would suggest you try getting the best focus by looking at a bright object ( white paper or sky ) with the ocular and then focus with parallax on target leaving ocular alone see how that works. With ocular your looking for best focus of cross hair nothing else.

 

[Billm]

i would suggest you try getting the best focus by looking at a bright object ( white paper or sky ) with the ocular and then focus with parallax on target leaving ocular alone see how that works. With ocular your looking for best focus of cross hair nothing else.

That’s how I’m doing it. I usually use the sky or a white wall. Just someone mentioned that if you have to move the side focus to “out of focus” to correct the parallax error, that you can sometimes correct the focus with the ocular focus. It doesn’t make a lot of sense to me that it would help, but I tried it and it didn’t help lol. I’m trying to figure out if there is a fix for: when the target is in sharp focus and I move my head slightly left or right, the crosshairs move laterally (parallax error). The only way I can eliminate the shift in sight picture is to have the side focus, slightly out of focus. I would think that could only be corrected internally. It kind of irks me, I know it’s not a $2000 Sightron, but for $300+ it should at least work correctly lol. I might make a focus wheel like you FT guys use and see if more precise adjustment helps. Of course the simple fix is: don’t move my head lol.

 

[Solo1]

If this is with the ghost and you have the buttpad all the way up try moving it down some and see if it positions your head more naturally

 

[Roamin Greco 1]

A couple of simple things that you probably know:

When you are focusing the ocular lens by aiming at the sky or a bright surface, the reticle should be instantly in focus, don't give your eye a second or more or else the muscles in your eye will focus on the reticle no matter what the setting is.

Second to expand on Solo1's last point, have someone look at you in different positions (offhand, bench, prone) that you would typically use and make sure your eye is lining up with the center of the scope.

Finally, proper and repeatable cheek weld is important. Some folks glue a felt dot on their stock so that they have a reference point they can feel with their cheek.

Good luck and let us know if you solve this problem.

 

[Billm]

If this is with the ghost and you have the buttpad all the way up try moving it down some and see if it positions your head more naturally

It’s with the Sonoran. I probably should raise the cheek piece on it. I will check the ghost too,

 

[Billm]

A couple of simple things that you probably know:

When you are focusing the ocular lens by aiming at the sky or a bright surface, the reticle should be instantly in focus, don't give your eye a second or more or else the muscles in your eye will focus on the reticle no matter what the setting is.

Second to expand on Solo1's last point, have someone look at you in different positions (offhand, bench, prone) that you would typically use and make sure your eye is lining up with the center of the scope.

Finally, proper and repeatable cheek weld is important. Some folks glue a felt dot on their stock so that they have a reference point they can feel with their cheek.

Good luck and let us know if you solve this problem.

Yeah, I understand cheek weld etc.. with offhand shooting it’s pretty easy to find the correct weld. But, I’m new to rests and squeeze bags etc., and using a folding table probably doesn’t help. I’m trying to let the rear rest do the work and applying a light touch to the cheek piece. But, maybe that’s the wrong way to tackle it. I’m having surgery in a couple of days and depending on how the recovery goes I might have to put off shooting for a little bit. When I can restart, I might start with a solid shooting bench with the correct height etc. I will get a solid foundation and work through the basics. I appreciate everyone’s help.

 

[FL22]

I’m having surgery in a couple of days

Hope everything goes well and you have a speedy recovery .

 

[Billm]

Hope everything goes well and you have a speedy recovery .

Thank you

 

[pan60]

best wishes get well soon!

 

[Solo1]

The height of your gun from the table and the height of your seat all come into play when trying to get comfortable and to be consistent you have to be comfortable.

 

[Billm]

The height of your gun from the table and the height of your seat all come into play when trying to get comfortable and to be consistent you have to be comfortable.

Yes, I’m pretty sure that is hindering me at this point. But, at least it’s easy to resolve. Thanks.

 

[Dogowski]

Yeah, I understand cheek weld etc.. with offhand shooting it’s pretty easy to find the correct weld. But, I’m new to rests and squeeze bags etc., and using a folding table probably doesn’t help. I’m trying to let the rear rest do the work and applying a light touch to the cheek piece. But, maybe that’s the wrong way to tackle it. I’m having surgery in a couple of days and depending on how the recovery goes I might have to put off shooting for a little bit. When I can restart, I might start with a solid shooting bench with the correct height etc. I will get a solid foundation and work through the basics. I appreciate everyone’s help.

Good luck on the surgery man! Here's to a speedy recovery.

 

[Pumacarl]

Bill, good luck and a speedy recovery!

 

[Joey 69]

Go for it, we know you can do it.

 

[Sr.airgunner]

A couple of simple things that you probably know:

When you are focusing the ocular lens by aiming at the sky or a bright surface, the reticle should be instantly in focus, don't give your eye a second or more or else the muscles in your eye will focus on the reticle no matter what the setting is.

Second to expand on Solo1's last point, have someone look at you in different positions (offhand, bench, prone) that you would typically use and make sure your eye is lining up with the center of the scope.

Finally, proper and repeatable cheek weld is important. Some folks glue a felt dot on their stock so that they have a reference point they can feel with their cheek.

Good luck and let us know if you solve this problem.

Very good point about the 1 second max view for the reticle ocular clarity. Most shooters do not realize how much their eyes compensate for a fuzzy view.

 

[Roamin Greco 1]

Very good point about the 1 second max view for the reticle ocular clarity. Most shooters do not realize how much their eyes compensate for a fuzzy view.

Thanks. These days, my vision and my brain are getting a bit fuzzy. ;o)

 

[hameditor]

Thanks. These days, my vision and my brain are getting a bit fuzzy. ;o)

Yeah, me too

 

[WillM]

Ok, this is a long read (and a lot of work) but it makes sense and improves things. Disclaimer: I copied this off the internet a while ago. It is not my work; I believe it’s from The Dark Lord of Optics (you can look him up)

Initial setup: Set magnification to highest setting and set side focus to infinity. Loosen the lock ring in front of the eyepiece (if it has a lock ring) and while looking at a blank wall or the sky, rotate the diopter several turns counterclockwise (in the positive + direction) until the reticle is visibly out of focus. One of the most important things is to not stare continuously through the scope. Make sure you have something distant to look at when you look away from the scope. Then glance through the scope for no more than a few seconds. Then stare out at a distant object again while making a small adjustment. Then rotate diopter back clockwise until the reticle is focused as sharply as possible. (Note: you might need to go past what you think is sharp until it starts to get a bit fuzzy again and then dial back to the “middle” position between both extremes.)

Fine tuning: Find a target that is very far away, so that it looks sharpest when the side focus is at the infinity setting. As you look through the scope (important that it remains steady) you can mess with the diopter by making minute adjustments either CW/CCW and see if the reticle and/or image improves any. You can also check parallax to ensure that small head movements don’t cause the POA to shift. When the target is in the best focus there should be no parallax movement, if there is parallax movement with slight movement of your position behind the scope then try to fine tune so the reticle stays locked on target with no movement.


Closeup tuning: Now find a target that is closeup, say 100 yards away, set your side focus until the object comes into best focus, does the reticle still look sharp? Check parallax to make sure there is no shift. Make minute adjustments to diopter if necessary. Check back at long distance and make sure parallax and focus are still good to go.

Final reticle adjustment: This should be done when you have nothing else to focus on within the FOV other than the reticle. Set your magnification to the lowest setting where you can still define all the hash marks of your reticle. You can either do it while pointing at a blank light-colored wall (keep the side focus at the infinity setting, so any of the minute features on the wall are blurred out) or at the blue sky. One of the most important things is to not stare continuously through the scope. Make sure you have something distant to look at when you look away from the scope (to reset your eye), I have even heard to give your eye about 30 seconds to rest. Then glance through the scope for no more than a few seconds. Then stare out at a distant object again while making small adjustments if needed to improve upon the reticle focus. Confirm both near and distant objects again.

Once you’ve performed the above 4 steps you should be set with your scope, it might be wise to mark your ocular and the scope tube with a pen or marker (especially if you don’t have a locking diopter) so you can return to this position if your scope is ever bumped out of alignment.

 

[Billm]

I’m going to post a link to the video that I watched, that prompted this question. I understand how to focus the reticle with the diopter. This video explains how to check if your’re experiencing parallax error. Parallax error like cant affects POI in a negative way if present. I believe most airgun shooters dial the side focus until the target is in perfect focus and assume it’s correct. I know I did. Joe Rhea explains this starting at 2:00 in his video. Two of my Discovery scopes are out of focus when the parallax error is eliminated. I wanted to know if anyone knew if there was a way to correct this in the scope. He explains that when this happens you pretty much have to decide if you want parallax correction or perfect target focus. If you accept no parallax correction and you do not align your head “exactly” the same way each shot, your POI will shift without you realizing it. Shooting Starlings, probably not a big deal, shooting bench rest at 50+ yds, it could matter.

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