Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Long Range Scopes and Other Optics
Parallax vs Focus
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Bart B" data-source="post: 1835582" data-attributes="member: 5302"><p>My Weaver model T scopes compensate for (adjust) parallax effects by twisting the objective bell back and forth to focus the target image in the first image plane. Exactly like the first adjustable objective lens scopes made a century or more ago. Their focal length is about 7.2" and move about 2/10ths inch forward changing range focus from infinity to 50 yards to focus the upside down target image in the first focal plane. Erector tube lenses invert it to right side up to focus again in the reticle plane. </p><p></p><p>As long as my aiming eye is on the scope optical axis, there is no parallax error regardless of the range the objective lens is set to focus on. Its easy to center the eye on that axis when it's at maximum eye relief plus a fraction.</p><p></p><p>That knob on the left side doesn't adjust anything other than where the target image is focused in the line of sight inside the scope. Exactly the same as adjustable objective lens barrels. Worst thing scope companies did was claiming it adjusted parallax instead of focusing for target range.</p></blockquote><p></p>
[QUOTE="Bart B, post: 1835582, member: 5302"] My Weaver model T scopes compensate for (adjust) parallax effects by twisting the objective bell back and forth to focus the target image in the first image plane. Exactly like the first adjustable objective lens scopes made a century or more ago. Their focal length is about 7.2" and move about 2/10ths inch forward changing range focus from infinity to 50 yards to focus the upside down target image in the first focal plane. Erector tube lenses invert it to right side up to focus again in the reticle plane. As long as my aiming eye is on the scope optical axis, there is no parallax error regardless of the range the objective lens is set to focus on. Its easy to center the eye on that axis when it's at maximum eye relief plus a fraction. That knob on the left side doesn't adjust anything other than where the target image is focused in the line of sight inside the scope. Exactly the same as adjustable objective lens barrels. Worst thing scope companies did was claiming it adjusted parallax instead of focusing for target range. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Long Range Scopes and Other Optics
Parallax vs Focus
Top