Does low parallax affect image quality?

[Peskadot671]

Does anyone know if scopes with 10 yards parallax affect image quality? I guess my question is...Do scope manufacturers have limitations or are they any compromises given up when they design scopes in different magnification ranges with a minimum of 10 yard parallax adjustment?

 

[B y r o n]

My guess is that the low end of parallax adjustment is limited by the design of the scope internals.

 

[Trigger Monkey]

Specifically talking about an adjustable parallax optic, the parallax range itself won’t necessarily affect the image quality. The quality of the lenses, the optical design/prescription, and the lens coatings are what’s going to separate the wheat from the chaff. That’s why there are scopes that cost <$800, focus down to 10 yards, and possibly look like like hot garbage on full mag. Then there’s the $5,000 Europeans that will be crystal clear focused down to 10 yards on high mag.

 

[Peskadot671]

I'll give an example and try to be more specific. Let's say if ZCO was to introduce their ZC420 or ZC527 with a 10 y/m - infinity adjustable parallax, would it cost them more to do so? Is it harder for a scope manufacturer to do? Would there be anything to give up such as DOF or sensitive/finicky parallax adjustment?

I'm just wondering why scope manufacturers limit their parallax to 25 yards, 50 yards. I personally think it would appeal to a wider market that not only covers centerfire but also rimfire and airguns if they start off with a minimum parallax of 10 yards.

 

[MikeMiller]

Parallax is either correct or not. Adjusted for too short or too long ruins the focus and can cause errors

 

[Trigger Monkey]

I'll give an example and try to be more specific. Let's say if ZCO was to introduce their ZC420 or ZC527 with a 10 y/m - infinity adjustable parallax, would it cost them more to do so? Is it harder for a scope manufacturer to do? Would there be anything to give up such as DOF or sensitive/finicky parallax adjustment?

I'm just wondering why scope manufacturers limit their parallax to 25 yards, 50 yards. I personally think it would appeal to a wider market that not only covers centerfire but also rimfire and airguns if they start off with a minimum parallax of 10 yards.

Yes it would cost ZCO more money to re-engineer the optical design of a current model in order to allow it to focus down to 10 yards. There’s no free lunch, they can’t just put a new knob on it with more numbers. The internals would need to allow for enough movement to get the full parallax range. That could mean redoing the optical prescription and or mechanical components. Regarding any difference in performance and image quality between these hypothetical versions, with good enough engineering you’re probably not going to be able to tell the difference.

I certainly can’t speak for the design requirements set by manufacturers but I speculate that part of it is simply institutional inertia and a little bit just not caring about a small niche of non-centerfire shooters.

 

[MikeMiller]

Remember adjust parallel by target being clearly in focus not by numbers on the knob

 

[Baron23]

Remember adjust parallel by target being clearly in focus not by numbers on the knob

Mike….I kinda think you are missing the pout of the OP’s inquiry which is basically “what are the tech and cost challenges of creating a SFP scope that will focus (parallax, right) to 10 yds vs the more common 25 or 50 yd designs.

 

[CSTactical]

Yes it would cost ZCO more money to re-engineer the optical design of a current model in order to allow it to focus down to 10 yards. There’s no free lunch, they can’t just put a new knob on it with more numbers. The internals would need to allow for enough movement to get the full parallax range. That could mean redoing the optical prescription and or mechanical components. Regarding any difference in performance and image quality between these hypothetical versions, with good enough engineering you’re probably not going to be able to tell the difference.

I certainly can’t speak for the design requirements set by manufacturers but I speculate that part of it is simply institutional inertia and a little bit just not caring about a small niche of non-centerfire shooters.

This post above sums it up pretty well, there would probably be some sort of compromise somewhere in the complete package whether it's on the parallax forgiveness, DOF, IQ or cost.

 

[Diver160651]

Does anyone know if scopes with 10 yards parallax affect image quality? I guess my question is...Do scope manufacturers have limitations or are they any compromises given up when they design scopes in different magnification ranges with a minimum of 10 yard parallax adjustment?

Technically, as others have said, with good glass, a wide range of focus control (parallax) doesn't degrade the image quality. My Swaro ATX 95mm spotter focuses down to about 3 yards. You can easily pay up to $8K for the Top-of-the-line ATX, and granted the size and weight are a non-starter for a file scope with a magnification range not being 5x. BTW I could NOT imagine enjoying this shallow DOF on a rifle scope.

Really though who needs a rifle scope laser-focused to 10 yards, at that distance, even with NRL22, you can pull zoom back and work well with most scopes already offering 25y parallax.

There certainly are things that can be negatively affected by changing the optical design for such a niche market, such as cost, scope size, weight, robustness, and probably overlooked, a shallow depth of field (less forgiving in the majority of the shooting scenarios).

Edited to add: as I was typing this, CS Tactical replied.

 

[MikeMiller]

Mike….I kinda think you are missing the pout of the OP’s inquiry which is basically “what are the tech and cost challenges of creating a SFP scope that will focus (parallax, right) to 10 yds vs the more common 25 or 50 yd designs.

My bad. Sorry

 

[Baron23]

Really though who needs a rifle scope laser-focused to 10 yards

The only thing I can think of is scope leveling against a plumb bob.....and wanting to do it in your garage/living room/etc.

My neighbors get a kick out of me (well, "kick" may be the wrong term haha) in the parking lot of my town house community with a table and the rifle set up leveling against a plumb bob at the far end of my garage.

I do this before taking it to the range and verifying/fine tuning the leveling.

Other than that....not at all sure.

Cheers

 

[AccuSol-ERN]

Probably off topic, but parallax related. I always hear people say......adjust it until the image is in focus. I may be an idiot but I adjust clarity with the eyepiece. I adjust parallax by setting the rifle up solid and somewhat on target.....then adjust the parralax knob while moving my head around without moving the rifle at all. I adjust until the reticle stops moving on the target while the rifle is perfectly still.

Is this just another way of skinning the cat or am I an idiot? My eyes (with glasses) always seem to auto focus even when I am trying to purposefully look at an image out of focus while adjusting a scope.

Ern

 

[MikeMiller]

You have 5-10 seconds or so before your eyes will try and focus an out of focus object. If you will allow your eyes to do this you will get eye strain and head aches
So look through scope make quick adjustments then look away a few seconds before looking through scope again. Focus on target not reticule. Reticule focus is done by diopter adjustment rear of scope

 

[Peskadot671]

Mike….I kinda think you are missing the pout of the OP’s inquiry which is basically “what are the tech and cost challenges of creating a SFP scope that will focus (parallax, right) to 10 yds vs the more common 25 or 50 yd designs.

Yes, this is what I'm referring to but FFP as well. As an example, I can choose any March optic and most of them have a minimum of 10 yards of parallax adjustment. This broadens the customer's decision making in choosing a scope for whatever application they would want to use it for. Why don't most scope manufacturers do this as well?

 

[Diver160651]

Probably off topic, but parallax related. I always hear people say......adjust it until the image is in focus. I may be an idiot but I adjust clarity with the eyepiece. I adjust parallax by setting the rifle up solid and somewhat on target.....then adjust the parralax knob while moving my head around without moving the rifle at all. I adjust until the reticle stops moving on the target while the rifle is perfectly still.

Is this just another way of skinning the cat or am I an idiot? My eyes (with glasses) always seem to auto focus even when I am trying to purposefully look at an image out of focus while adjusting a scope.

Ern

Well, if the scope is decent and you find yourself repeating this process, you've never really set up the ocular correctly in the beginning. You should not need to readjust the ocular at different distances and if the parallax-free image (moving your eyes off center) produces a fussy image you need to go back and set up the scope's diopter against an image-free setting so that the reticle is set correctly to your eyes.

 

[AccuSol-ERN]

Nope, I am not changing the ocular once it is set. I am simply setting the parallax by making sure the reticle doesn't move on the target when I move my head around behind the scope and keeping the rifle perfectly still.

I guess don't fix it if it is not broken. I am just wondering if I am missing out on something. I have a feeling there are a lot of people who may be getting a focused image while still having parallax. Granted a consistent cheek weld pretty much eliminates the parallax problem......or at least keeps the error consistent and repeatable.

Ern