Headbob method

[prosportfan]

When you try to eliminate parallax with your scope at a given distance and you use the headbob method, does your crosshairs still move from left to right? Because when I do the headbob method the crosshairs do not move up and down but they do move from left to right. Am I doing it right or am I doing something wrong?

[Artie]

"Head Bob" can be misleading. To me it means up & down and if that's what you did, left/right movement probably won't be detected. I move my head in a kind of circular fashion, like "around" the target and not N-S, E-W like the reticle. If the target/reticle move with relation to each other doing the circle thing, I know I've got parallax.

[prosportfan]

"Head Bob" can be misleading. To me it means up & down and if that's what you did, left/right movement probably won't be detected. I move my head in a kind of circular fashion, like "around" the target and not N-S, E-W like the reticle. If the target/reticle move with relation to each other doing the circle thing, I know I've got parallax.

See artie I move my head up n down and I won't see no movement. But if I go left to right there is movement. When I had a smaller Air max 4-12x with amx reticle, i could swear to no movement. Now I upgraded to the 4-16 airmax it seems like it's nowhere compared to the poser one. I sent it to Hawke and they said nothing is wrong with it.

[Artie]

Left and right movement is what you need to be concerned with. When you see it you will know it. If you don't see left/right movement (parallax), note where your side focus/AO (whichever you've got) range to index dot is and give it a good twist. Then view through the eyepiece and test for left-right movement again. You should see some movement (parallax).
You want to adjust the range until no movement is detected. That is a parallax free sight picture. You do have a scope with side focus or adjustable objective correct? If not you have a scope with fixed objective and preset range (fixed at one distance only). Whole different can of beans adjusting a fixed range scope..

[Scotchmo]

Parallax error can occur when the reticle does not lie on the focal plane. If you have a scope with adjustable parallax, you can use it to bring the focal plane coincident to the reticle.

If you "bob" your head to the eye-box boundaries, both vertically and horizontally, you should see about equal error. If you only bob a small amount, it's possible to only detect it in one direction. It is possible to eliminate parallax by keeping your eye in the perfect center of the scope, but that is an iffy proposition.

Ideally, minimum parallax occurs when the scope appears to be at it's clearest focus. But that is not always the case. You can play with the ocular adjustment as that might improve the parallax/focus agreement. When adjusting, best to do the head bob with the gun rested (hands off).

[Roadworthy]

Use great care when bobbing your head.  It's kind of tricky moving only your head with the gun shouldered.  If any part of your body moves the gun (and scope) will move as well.

[Artie]

Parallax error can occur when the reticle does not lie on the focal plane. If you have a scope with adjustable parallax, you can use it to bring the focal plane coincident to the reticle.

If you "bob" your head to the eye-box boundaries, both vertically and horizontally, you should see about equal error. If you only bob a small amount, it's possible to only detect it in one direction. It is possible to eliminate parallax by keeping your eye in the perfect center of the scope, but that is an iffy proposition.

Ideally, minimum parallax occurs when the scope appears to be at it's clearest focus. But that is not always the case. You can play with the ocular adjustment as that might improve the parallax/focus agreement. When adjusting, best to do the head bob with the gun rested (hands off).

+1. Much better explanation than my effort and Roadworthy is correct about the tricky part. It's best to support the gun with some kind of rest or support.

[prosportfan]

Left and right movement is what you need to be concerned with. When you see it you will know it. If you don't see left/right movement (parallax), note where your side focus/AO (whichever you've got) range to index dot is and give it a good twist. Then view through the eyepiece and test for left-right movement again. You should see some movement (parallax).
You want to adjust the range until no movement is detected. That is a parallax free sight picture. You do have a scope with side focus or adjustable objective correct? If not you have a scope with fixed objective and preset range (fixed at one distance only). Whole different can of beans adjusting a fixed range scope..

I have a SF Hawke Airmax with a amx reticle. I will give it a go tomorrow. Thanks artie and Roadworthy. The rifle is in a rest as well.