Optics: Parallax vs Focus

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Joe Salt said:
Do you leave it or hope the gun tracks in the same spot each time. I adjust to my eyes!
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The objective needs to be adjusted for zero parallax error after every target distance change. The ocular (eyepiece) must of course be adjusted for your eye to obtain a clear image of the reticle and target without unnecessary eye strain, but a wide range of settings will not be a big distraction for most people for casual shooting, but for serious, extended benchrest sessions where extreme accuracy counts, you would want to adjust it for the shooter's eye.
 
Brian I think that is what I said the scope has to be adjusted to each person's EYE! {I adjust to my eye} You to your's and you might get two that are the same. OH and did you know when conditions change, say at 1000 yard you may have to adjust again. So what is right for you this week may not be in two weeks. And what do you do when the Mirage is so bad and you have tried to adjust to no avail. Now you better know were you last adjustment was. No big deal been there done that.

Joe Salt
 
Joe Salt said:
OH and did you know when conditions change, say at 1000 yard you may have to adjust again.
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If you are referring to ocular (the adjustment which is for individual eye) no. It is not related to conditions outside the scope. Unless you feel temperature change causes internal dimensional changes, which would seem insignificant (to me) for the ocular, since there is already a very wide range of "close enough" anyway.

If you are referring to the parallax (objective) adjustment, I suppose internal changes from temperature might be in play, or atmospherics could change the effective distance to the target, but again I would think it would be insignificant, however I'm more willing to entertain the notion. Please explain in more detail.
 
Yes I was talking Parallax, and no I don't change the Ocular once I have that right. Oh and close enough doesn't get it done a 1000 yard, its right or it's not.I try to adjust the Parallax when it is overcast, then I mark it on the scope so if I am testing at 100 or 200 yards then go back to 1000 I can check to see if my eyes have tricked me again on were the mark ends up. And yes I know about going back to Infinity each time you adjust. Let me tell you this story, I adjusted an older fellas scope for him when I was much younger he was setting up and I look threw his scope and seen the parallax was not right so I asked him if I could adjust it. Needless to say he shot a 4.5" ten shot group with a 98 score. I don't do that anymore! Yes you are right it will change a little from week to week but I think some scopes more than others. I've noticed that before. But if you are in bad Mirage, [Atmospheric Condition] you're at the mercy of the shooting GOD's.

Joe Salt
 
Joe Salt said:
Let me tell you this story, I adjusted an older fellas scope for him when I was much younger he was setting up and I look threw his scope and seen the parallax was not right so I asked him if I could adjust it. Needless to say he shot a 4.5" ten shot group with a 98 score. I don't do that anymore!
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LOL Well, next time you'll know what to do to his parallax.

My shooting buddy, not unlike others, has intransigent ideas about scope adjustments. If he's not shooting groups well, and I look through his scope and notice the parallax error is pretty bad, and point it out to him, he'll say the target is in focus so I must be mistaken. There's simply no way he'll listen to reason. So I let him soldier on in his own fashion.
 
One of the great benefits of having the ocular (eyepiece) right is that you can have confidence, in heavy mirage, that if your objective or side focus adjustment has the target as sharp as it can be, that you have no parallax, even though things are moving around too much to be able to check by moving your eye. If you doubt this, check early or late, before the sun warms the ground, or after it has stopped shining on it directly, or when the wind is blowing all of the mirage away.
 
Brian always said you should learn something new every day, but you also have to remember it. Believe me there are shooters out there that haven't got a clue how to adjust a scope or what to do if they have a problem. I've seen guy's that had scopes go bad that didn't know what was wrong.

Joe Salt
 
When I've adjusted

Parallax out of my scope in the early morning, the sun warms the air creating shimmer making parallax adjustment, as Boyd said, difficult or impossible later in the day, I pull my eye back from the scope and do my best to look through the very center of the optical path where no parallax exists, assuming the x hair intersection is at the optical center. Greg
 
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I find that once the eyepiece adjustment has been properly done (which can take a fair amount of fiddling) , that I can have confidence that there is no parallax as long as the front or side adjustment has the target image at its sharpest, so even though I have changed yardage from say 100 to 200 in the middle of the day, that I simply focus the target image. This has become much less of an issue since the local matches (which I have not shot for a while, but still follow) have changed so that 100 and 200 are shot on different days, making middle of the day scope adjustments unnecessary. Of course keeping ones eye centered can do no harm, and may beneficial if the eyepiece adjustment is very slightly off, which may be more common than many would guess.
 
Brian Adams said:
tim,

Let me ask you this simple question:

Does the March manual explain how check for parallax error by moving the eye around behind the ocular and observing any apparent reticle motion against the target image?
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<crickets>

I thought not. But I can't download one of March's manuals to verify for myself. Does anyone else have one?
 
Brian Adams said:
<crickets>

I thought not. But I can't download one of March's manuals to verify for myself. Does anyone else have one?
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I believe it does. Understand one thing you might not have issue with or experience with. First of all, the primary reason the optics outfits all suggest the methodology the same is that the longer you need to look into the scope and fiddle, the more likely you run the risk that your eye adjusts and your reticle is not as clear as you think.
Secondly, as you get older and/or have any eye issues, you will find your eyes change and the need to readjust your high mag optics becomes somewhat more frequent. Doing it on a systematic basis, the suggested way, is, frankly more repeatable.
 
tim said:
I believe it does.
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If you have the manual, it should be a definite yes or no answer. Look for the something about relative motion between reticle and target.

tim said:
you will find your eyes change and the need to readjust your high mag optics becomes somewhat more frequent.
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I should have mentioned that I do look away and let my eye relax, repeatedly, when adjusting the ocular. The only difference, really, being that I have already focused the target image on the reticle plane, so I am not only observing the reticle, but also the coplanar target image as well. It makes it a lot easier to detect subtle changes in focus than just having the stark dark reticle against a light blank background. I'm sure others here will know what I'm saying. You should try it. After all, you can always readjust the scope afterwards using your choice of procedure, so there's no risk in just trying it out (something I would think you might want to do before denigrating it out of hand.)

tim said:
Doing it on a systematic basis, the suggested way, is, frankly more repeatable.
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Read my method again. It's quite systematic and repeatable, at least to this engineer's feeble mind. It's practically foolproof.
 
Your method is freakin wrong. Go back and re read your series of threads a mere 6 months ago. You know the one where YOU referenced the article published by Leupold. The very same article that states in the forth paragraph that the parallax adjustments to follow should be attempted AFTER the reticle is first focused. Looks like the reading for understanding comment was on target after all.
 
March scope owners manual clearly states how to adjust and look for parallax errors.
 

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tim said:
Your method is freakin wrong. Go back and re read your series of threads a mere 6 months ago. You know the one where YOU referenced the article published by Leupold. The very same article that states in the forth paragraph that the parallax adjustments to follow should be attempted AFTER the reticle is first focused. Looks like the reading for understanding comment was on target after all.
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Yep, that was then - this is now. I have new-found confidence in my own analytical ability, and have proven my method works - and better - for me.

As I said before, tim, by all means stay within your comfort zone. We can't all be pioneers. I only shared my "heresy" here as an FYI, but, as it turned out others, have had the same epiphany.

And, for the record, I've never said the published method is wrong, or can't work.
 
I heard yesterday,

glp said:
Parallax out of my scope in the early morning, the sun warms the air creating shimmer making parallax adjustment, as Boyd said, difficult or impossible later in the day, I pull my eye back from the scope and do my best to look through the very center of the optical path where no parallax exists, assuming the x hair intersection is at the optical center. Greg
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there are available or use to be, rear lens covers that have a small hole drilled in the center, @ a certain size, which automatically centers the eye. Think they would be of any value?

Pete
 
Having always been against the grin;

I have had my own method of adjusting my scopes. I find that, especially with 6x scopes, I need to move the ocular bell sometimes, depending on the day. It has worked well for me. I don't find that my high power scopes are as finicky as the 6x are. That European style ocular ring is of great benefit sometimes. T'would be nice if all scopes had it on em, IMHO.

Pete
 
WSnyder said:
March scope owners manual clearly states how to adjust and look for parallax errors.
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That's great except you kind of jumped ahead. Show where the instructions begin. For those wishing to check for themselves, go to the Deon optics site, the manual is there. It explains why the proper order should be used. It is entitled " To Begin With".
Now Brian, this means you do this first. This is because other systems give random results. Now I'd suggest you read this a few times.....really let it get absorbed.
 
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