Re: Help with Schmidt & Bender PMll 5-25X56
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wjm1000</div><div class="ubbcode-body">After focusing the crosshair to its’ sharpest point using the ocular lens adjustment, say at 5 power and viewing a target at say 500 yards, if I zoom to 25X the target gets distorted (out of focus) and can’t be cleared up using just the parallax adjustment, I have to use the ocular lens adjustment to get things in focus again. If I go to some intermediate power I have to redo the process all over again. Is this normal? I have several Nightforce scopes and don’t have this problem.</div></div>
It sounds as if you either didn't take the time to properly adjust the ocular/eyepiece for <span style="font-weight: bold"><span style="font-style: italic">your</span></span> eye, or that you do not know how to correctly adjust the ocular/eyepiece. Correct adjustment of the ocular/eyepiece is very important and should be done after the scope is positioned for best eye relief.
<span style="font-weight: bold">Adjustable Parallax models should always be set to <span style="font-style: italic">"Infinity"</span> prior to adjusting the eyepiece (the "Infinity" setting looks like an elongated, horizontal "figure eight"). Variable magnification models should be set to highest magnification.</span>
Below is the correct procedure for Diopter (Ocular/Eyepiece) adjustment for both fixed and variable power scopes. The procedure is the same regardless of scope manufacturer, or whether the objective/parallax focus is on the objective ring or is a side focus type.
<span style="font-weight: bold">NOTE:</span> If the scope is a fixed power unit skip steps 1 and 2 as they do not apply.
(1) Turn the magnification ring to maximum (highest power).
(2) Turn the Parallax focus to "Infinity" (the symbol for Infinity looks like a figure eight). <span style="font-weight: bold">NOTE:</span> Most non-side focus scopes use a ring on the objective bell to adjust parallax, and the distances are usually numbered. Side focus parallax adjustment knobs may or may not have distances marked.
(3) Turn the ocular bell/eyepiece all the way in.
(4) Aim the scope at a cloudless section of the sky (you don't want anything except sky in the view, or else your eye will naturally attempt to focus on the object in the view beyond the reticle.
(5) Look at something nearby, but not too close, then look through the scope at the reticle. If the reticle is out-of-focus turn it a bit to begin to focusing the reticle, but look away from the scope. <span style="font-weight: bold">Never look at the reticle for more than a couple of seconds when adjusting the eyepiece</span> (if you look at the reticle for more than a second or two your eye will naturally begin to adjust to bring the reticle into focus - and you don't want this to happen. <span style="font-style: italic"><span style="font-weight: bold">You want to be able to look through the scope and see a sharply focused reticle immediately with your eye relaxed</span></span>. This cannot be achieved by continuously looking through the scope and turning the eyepiece into focus in one continous motion because your eye will have already begun to adjust.
<span style="font-style: italic">Remember, look away every few seconds and make small adjustments to dial-in the Ocular/Eyepiece focus.</span> Once you have achieved this, you should not adjust the eyepiece at all, <span style="font-style: italic">except to maintain sharp reticle focus</span> as your vision changes over time <span style="font-style: italic">(it always does).</span> You may want to put a pen mark on the eyepiece indexed to the index dot on the scope tube - if the tube doesn't have an index mark use a pencil. That way, if someone else shoots your rifle and adjusts the Ocular you know where to return the adjustment to.
However, if you still cannot achieve simultaneous reticle and image focus after following the above directions for Eyepiece/Ocular Focus, it is <span style="font-style: italic">possible</span> that there is a problem with the scope.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wjm1000</div><div class="ubbcode-body">I also noticed that when changing power from high power to lower power the field of view increases as it should, however at around 8 power it starts decreases in size and continues to do so down to 5 power. Is this normal?
</div></div>
This effect is called <span style="font-style: italic">"tunnelling"</span>, and is "normal" on the S & B 5-25X.
Keith
