The spec says that the minimum parallax setting is 10 meters ( 5-25x56 PM II/LP/MTC ). I am wondering if that is acheivable at maximum magnification or the minimum ? I have tried to ask S&B but didn't get any reply so far. Thanks.
Rifle Scopes S&B 5-25x56 PM II/LP/MTC
- Thread starter new2scope
- Start date
Its acheivable on both. The 100 yard indoor range I go to here in SD makes us get on target at 25 yds before we can shoot at 100. And I'm running a SB 3-27.
I don't have a PMII 5-25X[56] MTC (I have three PMII 5-25X[56] DTs'), but I can crank all three (3) up to 25X or down to 5X and turn the Parallax Knob to 10 Meters and have the image in perfect focus at a measured 33 feet (objective lens surface to target face). The index mark (arrow) on the turret "saddle" doesn't line-up perfectly with the "10" on the Parallax Knob (I turn the Parallax Knob a little past the "10" as if the distance is slightly less than 10 Meters/33 feet), but that may be because I have a little correction dialed into the Ocular.
Based on my low sample rate (my three plus another couple dozen I've looked through and/or shot with over the years), it's apparent to me that Schmidt Bender really does take the time to calibrate their Parallax Knobs to correspond to the actual distances in Meters pretty closely. The key is adjust the Ocular Lens correctly after mounting your scope. Over the years I've seen a bunch of people here "chase the focus" because they didn't adjust their Ocular correctly during their initial scope set up. And a lot of people think they know how to adjust the Ocular but don't.
For instance, some Hide members have said that they continue to have parallax even after they've set the Ocular focus. One guy said that he was having parallax issues with four different scopes. Unless the scopes are all crap (two of them were from the same manufacturer), it's more likely that either the Parallax wasn't correctly set and/or he/she isn't consistent with cheekweld/position. Adjusting the Ocular Lens (aka the "Diopter", or "Eyepiece") on a scope is the first thing that should be done after the scope has been mounted and leveled. Below is THE CORRECT WAY, plain and simple, for parallax correction (even the Nightforce Owner's Manual suggests a somewhat questionable step in the procedure, namely instructing people to "look through the riflescope eyepiece at a light colored background such as a white wall...". Following that suggestion isn't the best way to focus the Ocular / Diopter / Eyepiece. Ideally you want to adjust the reticle without distraction to the eye, and the best way to eliminate any distraction is to have nothing else in the view except the reticle. This is why the Ocular should be adjusted while viewing the reticle against a cloudless sky (or at least a clear area of the sky). A blank wall is "OK", but clear sky is best because the reticle will be the only visible object within view.
NOTE: 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). NOTE: 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. Never look at the reticle for more than a couple of seconds when adjusting the eyepiece (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. You want to be able to look through the scope and see a sharply focused reticle immediately with your eye relaxed. 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.
Note that the threads on Diopter adjustments are normally very fine, so you may have to turn the Diopter more than you might expect before any appreciable difference in reticle focus is discernable. You will most likely have to make several small adjustments before you get the reticle perfectly and finely-focused for your eye, but it is very important that you do so. A lot of shooters' "chase the focus" because they didn't set their diopter adjustment correctly when they initially set-up the scope.
Remember, look away every few seconds and make small adjustments to dial-in the Ocular/Eyepiece focus. Once you have achieved this, you should not adjust the eyepiece at all, except to maintain sharp reticle focus as your vision changes over time (it always does). 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.
If you cannot achieve simultaneous reticle and image focus after following the above directions for Eyepiece/Ocular Focus, it is possible that there is a problem with the scope.
NOTE: Setting the diopter at the extreme end of it's adjustment range in either direction can affect the image focus. Also, since all of the lenses in a scope except for the reticle are curved, when using aggressively canted bases (as suggested by S & B for their PMII line) the eye may be pushed out of center of the lens slightly blurring the reticle. The quality of the lens and coatings, and the user's vision, i.e. astigmatism, can also affect the reticle focus.
Keith
No problem new2scope. It's always better to start out doing things the right way than trying to unlearn incorrect procedures and/or bad habits. Doing things right the first time almost always saves time, effort, frustration, and money down the road.
However, going back to parallax knobs and distance markings, don't assume that the distance indicators (if any), correspond accurately to actual distances on any scope, whether high end or low end scopes. It's the responsibility of the scope user to verify how accurate the markings are on their own. Not all scopes (upper or "low end"), have Parallax Knobs that have been calibrated/tweaked to have the actual distance correspond closely to distance indicators on the Parallax Knob. Some scopes have no markings on the Parallax Knob at all with the exception of markings at point blank and infinity. I remember when the "old" Premier Reticles company sold the Heritage Tactical scopes with unmarked Parallax Knobs, stating something to the effect that parallax markings are never going to be accurate anyway
I used my personal experience with PMII scopes because you asked about PMII 5-25X[56] LP MTCs'. As I said - based on my low sample rate of maybe two dozen or so PMIIs' I've looked through and/or shot with over the years, it seems apparent to me that Schmidt Bender calibrates PMII Parallax Knobs to correspond to the actual distances in Meters pretty closely. YMMV.
The bottom line is that no one should assume that distance indicators on Parallax Knobs on all scopes are calibrated to a fine degree of accuracy. Users have to verify how accurate the markings are on their own.
Keith
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