1-4 and 1-6 optics discussion

[00bullitt]

Everything that has magnification has Diopter shift, that's why there is the ability to set the focus on most (if not all) magnification optics.

That is not technically true. A well and properly designed optic should not have any noticeable diopter or reticle focus shift through mag range. Diopter is there to accommodate varying types of vision. Typically you get adjustment range from -2.5 to +2.5. Most of the time you can accommodate adjustment to forego using reading glasses as that is the amount of range it has.

If you truly have an optic with as much shift as Unobtanium states and it is verifiable that it IS the optic and not an individual's eye issue, then something is wrong with the optic.

Diopter can add or decrease magnification very slightly from stated, so it is possible to go just a hair past true 1x (unity) at extreme ends of diopter adjustment.

I rarely if ever have to adjust diopter from a factory setting on any of my scopes.

In a design sense, not as much focus is placed on diopter travel on true 1x variables compared to that of a higher magnification variable scopes as they are not designed for glassing during long periods of time and won't generate the fatigue that higher magnification scopes are capable of.

[Gray222]

That is not technically true. A well and properly designed optic should not have any noticeable diopter or reticle focus shift through mag range. Diopter is there to accommodate varying types of vision. Typically you get adjustment range from -2.5 to +2.5. Most of the time you can accommodate adjustment to forego using reading glasses as that is the amount of range it has.

If you truly have an optic with as much shift as Unobtanium states and it is verifiable that it IS the optic and not an individual's eye issue, then something is wrong with the optic.

Diopter can add or decrease magnification very slightly from stated, so it is possible to go just a hair past true 1x (unity) at extreme ends of diopter adjustment.

I rarely if ever have to adjust diopter from a factory setting on any of my scopes.

In a design sense, not as much focus is placed on diopter travel on true 1x variables compared to that of a higher magnification variable scopes as they are not designed for glassing during long periods of time and won't generate the fatigue that higher magnification scopes are capable of.

I do not have to adjust focus either, other than once when I banged the optic on something. Other than that I've never had to do it, and the diopter shift, even though unnoticeable sometimes is still there.

Those who have issues with it may need to try various optics or end up with a 1x rds...

[00bullitt]

I didn't realize that the Short Dot had been out as long as it has. I picked one up in 2004-5 and found out quickly that I had no need for FFP in a low powered variable, but that I really liked the daylight visible dot. The reticle was useless below 2.5x and if it had not been for the dot, you would not have had an aiming reference. My preference quickly went to the S&B Zenith 1-4. I gave up the graduated Mil reticle, but I worked around that with a good zero and knowing POA/POI and could still dial using a home-made label BDC. I really don't see the benefit for FFP until I am beyond 6x and moreso under more specific situations. I can work with an SFP just fine up to 10x. Beyond that and the FFP starts to provide some real advantages in certain situations.

On a 1-4, If I was less than 4x, I was not using the reticle to its advantage to require FFP capability; only to improve PID, target hold refinement and still maintain a wide FOV. If I was at mid range, I was usually inside 200 yards and could deal with the target/threat just fine using a 200 yard zero. When I stretched out beyond 200 or required more magnification for a more precise shot, then I was on 4x and the reticle was true. Same with the 1-6 optics. I was sporting a Swaro Z6i before anyone else even knew what it was. 3-Gun quickly popularized the Z6i as it was the only real game in town for a semi-affordable daylight visible 1-6 outside of the ridiculously priced CQBSS with H27D reticle option that was just hitting the scene.

I was running my Z6i at the Fort Benning 3 Gun in 2009 when Dave Neth won Tac Optics with one of the prototype CQBSS 1-8's. At that match, it was advertised to be $5k but they were most definitely the first one to the dance with a 1-8 and it was all the rage then.
Granted the Z6i still dominates in 3-Gun today as the most popular optic. The Kahles is gaining popularity but the $400 price difference scares some off. It is SFP and does not hold anyone back. The Z6i has a great visible reticle, a super wide FOV, and nice glass and has proven to be robust enough to hold up to the rigors of the game. It is not a combat optic by any means; it is a dangerous game scope that was adapted and works well......in SFP.

FFP has its place and there are those that prefer it. It isn't wrong.....just different.

[00bullitt]

I do not have to adjust focus either, other than once when I banged the optic on something. Other than that I've never had to do it, and the diopter shift, even though unnoticeable sometimes is still there.

Those who have issues with it may need to try various optics or end up with a 1x rds...

If it is unnoticeable, how do you know it is there?

Unnoticeable.....meaning it takes a dioptrometer to identify it.

[StraitR]

I tried the Aimpoint magnifier behind a T-1 and didn't care for it, as the dot turned into a big comma. Kevin probably won't remember, but he witnessed my disdain at a local carbine match where I took about seven shots at 200yard gong before jettisoning the 3x and quickly making the follow-up shot without it. That was about four years ago, and the experience is what drove me to research low power variables. I wanted the closest thing to a red dot at 1x, and for me that ended up being the TR24. Eye box and FOV are generous, and the red triangle is just as easy to track as the dot in my T-1. Downsides, as previously mentioned, are shooting small targets at distance as there is no true reticle to speak of and the triangle is 4.2moa. I think the TR24 is still a viable option if most of your work is done at 1x, but if you do regular business at distance, I'd look elsewhere. Just depends on your needs and priorities.

I've had it mounted on two 5.56 AR's for general purpose use, an LMT MWS for hog hunting, and on a .308 Browning A-bolt for hog hunting. Overall, it's performed well, and I've been happy with it. As such, I have recommended it many times to others and still do if it meets your needs.

Once upon a time, the Noveske was painted, and the TR24 still sports the matching paint job. The MWS has since been sold off in preparation of an SR25 project, and the TR24 now sits on the SR15.

[GJM]

Can someone give the short explanation of first and second focal plane, and how that impacts use of the variable on carbines?

[breakingtime91]

Im.really interested in the accupower with mil dot reticle

[00bullitt]

Can someone give the short explanation of first and second focal plane, and how that impacts use of the variable on carbines?

SFP = Reticle stays constant in size but is only true on a calibrated magnification setting; usually max - the target magnifies against a fixed reticle causing the subtensions to change through magnification.

FFP = Reticle stays in proportion to the target throughout the magnification range. The target and the reticle magnify together (in proportion) and the reticle subtends properly through the entire magnification range.

FFP could have benefits when using graduated or BDC style reticles, but in combat variable true 1x optics, the mag range would really need to support it in my opinion. I find no benefit below 6x but YMMV.

[Gray222]

If it is unnoticeable, how do you know it is there?

Unnoticeable.....meaning it takes a dioptrometer to identify it.

Well I have to set it first, once I do its unnoticeable.

[00bullitt]

Well I have to set it first, once I do its unnoticeable.

Ok, then that's not diopter shift; its just setting the diopter or in laymens terms.....focusing the reticle. The purpose of diopter is to focus the reticle for the users eyes. It has nothing to do with target focus. True diopter range should take the target and reticle out of focus sequentially.

Diopter shift is when you set diopter for your eyes, but change magnification and the reticle goes out of focus (no longer crisp and sharp). Typically diopter shift is fatiguing; meaning your eyes have to compensate for both planes of focus - the reticle is out of focus when you look at it and then your eyes usually try to accommodate and bring it in focus and then the target goes blurry and when you look at the target, then it comes back in focus making the reticle blurry.
That is diopter shift.