bohemr13
X96 MONTHS
Premium Member
First Sergeant
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Setting up a FFP rifle scope - A simple PSA on Diopters
03/02/2015 Last edited 03/03/2015 by bohemr13
(9 votes)
I recently had a somewhat disgruntled customer return a scope because he complained of it being defective. He sent it back to the manufacturer, the manufacturer told him that it passes all tests and it resolves the 1/16th inch lines at 100yd successfully. No issue.
I told him over the phone how to setup the optic but there was something lost in translation because it didn't fix the problem. Once I opened the return box I knew why immediately.
Now that I think back on it, I'm not surprised at the issue since the comparison optics he mentioned are both SFP units. So, for those that have a FFP scope that may or may not be setup properly, here's a quick method to get you rolling. With a little practice it can be done from soup to nuts in <30 sec.
First and foremost: If you have a First Focal Plane scope, it's less forgiving than a Second Focal Plane scope. Failure to follow through on details will yield issues.
Try this if you're having issues or if you've never setup the diopter and parallax before. I had to figure this out the hard way. I've never seen it clearly spelled in a scope manual that worked. Here's how I do it and the process works.
1) Set to Max Power
2) Parallax set to Infinity (this is very important)
3) Point it at a solid, light background like a white wall or blue sky. You don't want anything except a solid, light color to look at.
4) Start from the diopter all the way into the occular and rotate out.
Don't stare into the optic, open and close your eye as you adjust such that you have no more than about 1 second open, 4-5s closed.
In short order you can get the diopter very closely adjusted such that it will be crisp at all but the finest areas of the reticle.
Once you're there, small adjustments are made and you should focus your attention to the smallest details such as 1/10th mil hash marks, square corners in the reticle, etc.
Flick your eye open, then closed. Look at the reticle picture and see if it's crisp. Repeat as necessary until you have the diopter adjusted properly.
Lock down the ring on your diopter or wrap it with electrical tape and lock it down. Perhaps a sharpie with a witness mark between the occular and diopter ring. Something to reference it for the inevitability that it will get bumped.
Following these steps would have saved this gentleman significant frustration and hassle, as well as avoiding some of the bad information being circulated about some of the new scopes on the market.
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talivXGunny Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/02/2015
i'm confused. how could you tell immediately by looking at the scope that the diopter wasn't adjusted?
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Captramrod01
XGunny Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
I'm guessing the diopter was all the way in or out. Pretty uncommon setting for pretty much anyone. That , or he quickly focused it for him and the scope was fine?
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lennyo3034XFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
Thanks for this write up, I recently started doing this to good success. I find taking it outside and looking at the sky better than looking at a wall. I used to set it "all the way in" as it would give me a clear enough reticle. However what I noticed was that if I stared at the crosshairs for a long time, the target would get blurry as my eye had adjusted to the reticle. After using this method, I can stare at the crosshair for longer without the target getting blurry.
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6x47SteveXFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
It's kind of funny in a way/ more so sad, because over the last few years every novice and even extending to most shooters I've met at the range have had no idea that the diopter can be adjusted, LOL ?!?
Doesn't anybody read instructions anymore???
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skinman3834XPrivate
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
(1 vote)
I have a buddy whose father wrote software for john deere. He would get calls all the time from people trying to use the software.
He called these people RYFMS. Read Your F@#$% Manual. LOL
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bohemr13
X96 MONTHS
Premium Member
First Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015 Last edited 03/03/2015 by bohemr13
taliv wrote:
i'm confused. how could you tell immediately by looking at the scope that the diopter wasn't adjusted?
The parallax knob was set ~ 1/4 of the way between 100 and 200yd.
When I spun the parallax to infinity, rotated the diopter about 1/2 turn it turned crystal clear all the way to the edges of the scope picture instantly.
6x47Steve - I agree though this was not the case. The manual that comes with the scope is translated poorly from German. This is purely the fault of the manufacturer... ESPECIALLY because they just ripped off the old manual from a different scope and threw it in the box with the new one.
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LukeNCMXXSergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
(1 vote)
Change the title so it mentions diopter adjustment and then sticky this please.
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USALTC
X42 MONTHS
Premium Member
Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
Excellent. Reads just like the instructions from Nightforce that came with my F1's.
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RthurDXFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/03/2015
(1 vote)
Good psa Bohem. I had to deal with this very problem recently.
R
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SPAK7XFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/03/2015
Great post! Found this to be exactly true on my t5xi steiners...I thought initially I had clarity and Chromatic abberation issues, but when I finally got the diopter set CORRECTLY all those issues went away. Thanks for posting bohem.
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Diver160651
XFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/03/2015
Diver160651 wrote:
whats a diopter?
Crap now that someone is making this a sticky, I am going to remove my transparent attempt at a joke..
It would be good if the OP of the PSA explain why the first focal plan (that changes magnification with the target) is more critical to adjustment than a SFP.
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lennyo3034XFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA
03/04/2015
Diver160651 wrote: Diver160651 wrote:
whats a diopter?
Crap now that someone is making this a sticky, I am going to remove my transparent attempt at a joke..
It would be good if the OP of the PSA explain why the first focal plan (that changes magnification with the target) is more critical to adjustment than a SFP.
Good point. My guess is that you're focusing the reticle and obviously the reticle is in a different location on FFP and SFP. I would like a deeper explanation as to why it's more critical for FFP though.
I have noticed my SFP scopes are more forgiving of diopter setting.
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bohemr13
X96 MONTHS
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/04/2015 Last edited 03/04/2015 by bohemr13
(1 vote)
Whomever asked: The optic in question was a T5Xi 5-25.
FFP is more sensitive due to the location of the reticle in the optical stack. Small errors are more sensitive and the issues are magnified.
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cowholyXFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/06/2015
Would you use the same steps for a SFP scope?
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bohemr13
X96 MONTHS
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First Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/06/2015
(1 vote)
I do. Unless you have clear instructions from the manufacturer stating something different this is a good method to start with.
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TRH1962XCorporal
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/06/2015
3) Point it at a solid, light background like a white wall or blue sky. You don't want anything except a solid, light color to look at.
From No .3: Can I do this at any distance in my home? Say like from 15ft away from the wall adjusting the diopter?
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bohemr13
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/07/2015
(2 votes)
Yes, the goal is focusing the diopter. You're not trying to focus the wall, you just want the reticle to be crisp.
Parallax at infinity is important.
I find it works best on a blue sky but you can do it indoors.
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jeo556XSergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/10/2015
Thanks for the walk through, I followed a different and less straightforward procedure that left me wondering if I had it as good as can be. Illness doing this tonight.
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snubbieXPrivate
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/12/2015 Last edited 03/12/2015 by snubbie
bohemr13 wrote: Yes, the goal is focusing the diopter. You're not trying to focus the wall, you just want the reticle to be crisp.
Parallax at infinity is important.
I find it works best on a blue sky but you can do it indoors.
I tried this method and found if I optimized the diopter/reticle setting for max magnification and max parallax (as per instructions above), the rest of the magnification range (the reticle) was out of focus by 1/4 turn on the diopter. Backing off the diopter by 1/4 turn the entire magnification range preserves the reticle's focus (but not as crisp as it originally was at the highest magnification). Is this normal for this procedure ?
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dondlhmn
XGunny Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/12/2015
What amazes me is that so many shooters have absolutely NO IDEA that the diopter on the "eyeball end" of a scope is to bring the RETICLE ONLY into good, clear and sharp focus for them and then the "parallax adjustment", whether it be around the objective lens or a side mounted knob, is for use at varying distances and HAS NOTHING TO DO WITH THE FOCUS OF THE RETICLE!!! What they need to do is to focus the reticle and then LEAVE IT ALONE. It may require changing when the scope is used by a different shooter with different vision than the first shooter or when the shooter encounters. over time, some kind of a change to his vision, but SHOULD NOT REQUIRE any fiddling if the original shooter has once set it correctly when they first receive it and put it into use and then his/her vision does NOT CHANGE.
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snubbieXPrivate
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/12/2015
dondlhmn wrote:
What amazes me is that so many shooters have absolutely NO IDEA that the diopter on the "eyeball end" of a scope is to bring the RETICLE ONLY into good, clear and sharp focus for them and then the "parallax adjustment", whether it be around the objective lens or a side mounted knob, is for use at varying distances and HAS NOTHING TO DO WITH THE FOCUS OF THE RETICLE!!! What they need to do is to focus the reticle and then LEAVE IT ALONE. It may require changing when the scope is used by a different shooter with different vision than the first shooter or when the shooter encounters. over time, some kind of a change to his vision, but SHOULD NOT REQUIRE any fiddling if the original shooter has once set it correctly when they first receive it and put it into use and then his/her vision does NOT CHANGE.
Are you saying the procedure outlined above for the initial setting of the diopter/reticle focus is irrelevant ?
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dondlhmn
XGunny Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/12/2015 Last edited 03/12/2015 by dondlhmn
(1 vote)
snubbie wrote:
Are you saying the procedure outlined above for the initial setting of the diopter/reticle focus is irrelevant ?
Of course not. Was I somehow not clear enough that I gave you that idea? My apologies if I did. Did I say or imply that it is irrelevant? NO........Let me explain this AGAIN........EACH SHOOTER that uses that scope has to set the diopter up to match their vision and if NOT set up, the reticle will likely be out of focus
FOR THAT PARTICULAR SHOOTER DUE TO HIS/HER vision specifics.THEN, if another shooter uses it, the reticle may be out of focus for that NEXT SHOOTER unless they set it up/focus it again to meet their OWN EYES' differences from the first shooter's eyes. SIMPLE, NOT COMPLICATED!!!!
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snubbieXPrivate
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/12/2015
dondlhmn wrote: snubbie wrote:
Are you saying the procedure outlined above for the initial setting of the diopter/reticle focus is irrelevant ?
Of course not. Was I somehow not clear enough that I gave you that idea? My apologies if I did. Did I say or imply that it is irrelevant? NO........Let me explain this AGAIN........EACH SHOOTER that uses that scope has to set the diopter up to match their vision and if NOT set up, the reticle will likely be out of focus
FOR THAT PARTICULAR SHOOTER DUE TO HIS/HER vision specifics.THEN, if another shooter uses it, the reticle may be out of focus for that NEXT SHOOTER unless they set it up/focus it again to meet their OWN EYES' differences from the first shooter's eyes. SIMPLE, NOT COMPLICATED!!!!
Thanks for the clarification. I was trying to discern if your post was a response to a specific post or the instructions.
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Thrust911
XFirst Sergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
03/19/2015
Good stuff! I Appreciate you putting the information up for folks.
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SHootSTraight22XSergeant
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
04/15/2015
I thought I had this down pat but I guess not. I've always done it this way but didn't relies the focus needed to be set to infinity. I've been setting mine shooting groups at 100yds or on white steel at 727yds.. The cross hairs are perfect black and on the same plane with the targets but since I wasn't setting focus to infinity could this be why I shoot .2-.3 groups some days and 1in groups the next with 1 flier round making them 1 inch?? Even the 1moa 100yd groups have two shots bugholing or .3 max but there are the unexplained fliers off to one side.. I was wondering if my cross hairs were slightly dancing from my head not being anchored exactly the same every shot. Kind of like using a peep site on a bow and not using one. With a bow though it's easier I might add to keep the same anchor point under the jaw line for me but if the scope isn't properly adjusted I'm wondering if slight movements left right up and down with my head could be causing 1 inch movements at 100yds with the center of my cross hairs?? Is that it?
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nogunjoe
XCorporal
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Re: Setting up a FFP rifle scope - A simple PSA on Diopters
05/02/2015
ATACR F1 synchronizing the Parallax, Focus and Diopter
An alternative method.
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