Rifle Scopes  Setting up a FFP rifle scope - A simple PSA on Diopters

derekthehunter

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bohemr13

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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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663 posts this site
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
Rating: 3.2/5 this site
732 posts this site
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
Rating: 3.4/5 this site
1640 posts this site
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
Rating: 3.4/5 this site
8046 posts this site
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
Rating: 3.0/5 this site
19 posts this site
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
Rating: 3.6/5 this site
7824 posts this site
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
Rating: 3.5/5 this site
398 posts this site
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
Rating: 2.9/5 this site
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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
Rating: 3.3/5 this site
2113 posts this site
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
Rating: 3.4/5 this site
1777 posts this site
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
Rating: 3.6/5 this site
2158 posts this site
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
Rating: 3.4/5 this site
1640 posts this site
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
Rating: 3.1/5 this site
1055 posts this site
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
Premium Member
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
Rating: 0.0/5 this site
74 posts this site
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

X96 MONTHS
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First Sergeant
Rating: 3.6/5 this site
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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.
Rate now:
jeo556XSergeant
Rating: 3.1/5 this site
464 posts this site
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.

Rate now:
snubbieXPrivate
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27 posts this site
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
Rating: 0.0/5 this site
27 posts this site
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
Rating: 3.1/5 this site
66 posts this site
Re: Setting up a FFP rifle scope - A simple PSA on Diopters
05/02/2015

ATACR F1 synchronizing the Parallax, Focus and Diopter

Thanks for sharing the information, very informative and educative



An alternative method.
 

JCHayes

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May 18, 2020
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bohemr13

X96 MONTHS
Premium Member
First Sergeant
Rating: 3.6/5 this site
7824 posts this site
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.
Rate now:
talivXGunny Sergeant
Rating: 3.2/5 this site
663 posts this site
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?

Rate now:
Captramrod01

XGunny Sergeant
Rating: 3.2/5 this site
732 posts this site
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?

Rate now:
lennyo3034XFirst Sergeant
Rating: 3.4/5 this site
1640 posts this site
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.
Rate now:
6x47SteveXFirst Sergeant
Rating: 3.4/5 this site
8046 posts this site
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???
Rate now:
skinman3834XPrivate
Rating: 3.0/5 this site
19 posts this site
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

Rate now:
bohemr13

X96 MONTHS
Premium Member
First Sergeant
Rating: 3.6/5 this site
7824 posts this site
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.
Rate now:
LukeNCMXXSergeant
Rating: 3.5/5 this site
398 posts this site
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.

Rate now:
USALTC

X42 MONTHS
Premium Member
Sergeant
Rating: 2.9/5 this site
293 posts this site
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
Rating: 3.3/5 this site
2113 posts this site
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
Rating: 3.4/5 this site
1777 posts this site
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.
Rate now:
Diver160651

XFirst Sergeant
Rating: 3.6/5 this site
2158 posts this site
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.



Rate now:
lennyo3034XFirst Sergeant
Rating: 3.4/5 this site
1640 posts this site
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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7824 posts this site
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.
Rate now:
cowholyXFirst Sergeant
Rating: 3.1/5 this site
1055 posts this site
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
Premium Member
First Sergeant
Rating: 3.6/5 this site
7824 posts this site
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.
Rate now:
TRH1962XCorporal
Rating: 0.0/5 this site
74 posts this site
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?

Rate now:
bohemr13

X96 MONTHS
Premium Member
First Sergeant
Rating: 3.6/5 this site
7824 posts this site
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.
Rate now:
jeo556XSergeant
Rating: 3.1/5 this site
464 posts this site
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.

Rate now:
snubbieXPrivate
Rating: 0.0/5 this site
27 posts this site
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 ?
Rate now:
dondlhmn

XGunny Sergeant
Rating: 3.0/5 this site
631 posts this site
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.

Rate now:
snubbieXPrivate
Rating: 0.0/5 this site
27 posts this site
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

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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

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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

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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.
Thanks for the good info. I have a new FFP scope coming.
 

hindmarsh

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I listened to a podcast with ZCO and they described a different process for FFP scopes. They recommend a low magnification, I think 7-10x, and adjusting for clarity at 100 yards or so. Try it both ways and see what yields the best results throughout the magnification range.
 

Nathan Gravitt

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bohemr13

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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.
Thanks for this! My first first focal plane scope is on order. I don’t even know if I’ve ever heard of a diopter before. Guess I’m showing my ignorance
 

Nathan Gravitt

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i just read a nice little article in the April 2020 Guns and Ammo magazine written by Tom Beckstrand in which he describes a technique to adjust / minimize parallax

STEP 1
point scope at neutral background

look at reticle for a few seconds, look away, adjust DIOPTER, repeat until reticle is in focus …(don’t look at reticle while you’re adjusting diopter)


STEP 2
put up target with clearly defined small aiming point (i.e. 1 inch peel and stick paster dot)

use SIDE FOCUS KNOB (parallax knob) to get target sharp

stabilize rifle on bags or rests so it stays on target without having to touch the rifle

without touching the stock, move your face around to confirm no reticle movement relative to target.

if there is movement of the reticle relative to the target make small adjustments to the DIOPTER till the reticle no longer moves
This seems even more simple than the original write up and it actually makes sense that you may need to make a minute adjustment
 

Moe Ron

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Vortex podcast episode 138
Has their optical engineer explaining details.
Maybe too in the weeds but interesting to me
 

308pirate

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    I don’t even know if I’ve ever heard of a diopter before.

    That's because gun people repeat technical terms without understanding WTF they're talking about.

    What everyone here incorrectly calls a diopter is correctly called "reticle focus knob". They are talking about the rotating portion of the eyepiece, which is turned to focus the reticle to your vision. In some scopes the entire eyepiece is rotated.

    A diopter is an optical measurement to describe the focusing power of a lens. A diopter is defined as 1/focal length. The numbers that your optometrist writes in your prescription are in diopters. The lab uses them to grind your lenses (or make your contacts) to the correct profile that will change the focal length of your eyeball so that the light converges on your retina.
     
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    Nathan Gravitt

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    That's because gun people repeat technical terms without understanding WTF they're talking about.

    What everyone here incorrectly calls a diopter is correctly called "reticle focus knob". They are talking about the rotating portion of the eyepiece, which is turned to focus the reticle to your vision. In some scopes the entire eyepiece is rotated.

    A diopter is an optical measurement to describe the focusing power of a lens. A diopter is defined as 1/focal length. The numbers that your optometrist writes in your prescription are in diopters. The lab uses them to grind your lenses (or make your contacts) to the correct profile that will change the focal length of your eyeball so that the light converges on your retina.
    Now that’s crazy. I adjust that every time. I don’t even see how you could shoot a scope without adjusting that
     

    Nathan Gravitt

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    Now that’s crazy. I adjust that every time. I don’t even see how you could shoot a scope without adjusting that
    Why does the article differentiate between first focal plane and second focal plane if that’s the case? I’m agreeing with you but just don’t understand why you wouldn’t have to adjust it on a second focal plane scope?
     

    308pirate

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    Why does the article differentiate between first focal plane and second focal plane if that’s the case? I’m agreeing with you but just don’t understand why you wouldn’t have to adjust it on a second focal plane scope?

    The reticle has to be focused to your eye regardless of which focal plane it is on, first or second.

    Someone with more optical engineering knowledge than I will need to explain if the procedure for adjusting the reticle on a second focal plane scope is different than on a FFP scope. @koshkin
     

    Nathan Gravitt

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    The reticle has to be focused to your eye regardless of which focal plane it is on, first or second.

    Someone with more optical engineering knowledge than I will need to explain if the procedure for adjusting the reticle on a second focal plane scope is different than on a FFP scope. @koshkin
    I agree, which is what I was meaning to say. The original article seems to state theat those using a second focal plane scope haven’t had to do this step before?
     

    koshkin

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    The reticle has to be focused to your eye regardless of which focal plane it is on, first or second.

    Someone with more optical engineering knowledge than I will need to explain if the procedure for adjusting the reticle on a second focal plane scope is different than on a FFP scope. @koshkin

    I did a couple of videos on that a little while ago.

    There are a couple of difference with FFP scopes, some perceptual and some due to technical differences.

    Let me know if this helps. I've been asked to do something simpler and more to that point, so I should probably do one.



    ILya
     
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    308pirate

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    The original article seems to state theat those using a second focal plane scope haven’t had to do this step by step

    I didn't get that impression. Regardless you and I are both right, all scopes need to have their reticle focused to the user's eyesight.
     
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    GrumpyOleFart

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    When excitement and enthusiasm overwhelms the concentration required.
    Perfect preparation, practice, prevents piss poor performance.
    We have all played in that field.... at least I certainly have.😈
     

    JAS-SH

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    I agree with the original post. That said, there is a quicker way (for me anyway) to get the reticle really close quickly. I do everything pretty much as per the original post except that I start at the lowest magnification. The reticle image is very small at that magnification.

    Think about it this way, when you get your eyes checked, the top line on the chart with those large letters looks a heck of a lot sharper than the last line at the bottom. So, at lowest magnification and with the diopter screwed all the way in the little reticle will look terribly out of focus. Much more so than at full magnification.

    At that point I turn the diopter adjustment out until the reticle gets real sharp, eyes open all the time. Then I adjust it back and forth slightly with my eyes closed and recheck with eyes open. It's really easy to see the when that small reticle is OOF. I do this until it as clear as I can make it. Only THEN do I go to full power and do very minor adjustments with the same method as the original post. It wont need much adjustment at all. It is much quicker for me to do it that way. Plus, as a bonus I just checked diopter at both ends of the magnification spectrum....
     

    MLS2GO

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    To the OP Thanks. I am excited to see how far away was on my FFP Scopes.