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Rifle Scopes Why do you think an adjustable parallax feature is needed on LPVOs? ? ?

Anyone else ever notice that the parallax adjustment from 10==>50 (or whatever your min parallax is) is huge, but from 500==>infinity is negligible? That’s a hint. People arguing against math and physics is fucking comical. Parallax error becomes increasingly insignificant as the target distance increases.

Do LPVOs need a focus knob? IDK. How do fixed parallax scopes maintain good focus across a wide range?
Coupld of quick comments.

A 50yd field-zero followed by a 250yd shot can result in up to ≈ 3/4 MOA optical error from tolerance stacking. With spec mods we can reduce this somewhat, but not eliminate it (eg: 200-275M fixed parallax setting yields cumulative ±.5MOA error).

End user requirements will determine if taking a 2MOA shot is really necessary at 250yd. Its all eye of the beholder stuff. Nobody is going to miss an IPSC at <50m because of this. :ROFLMAO:

(calcs per the posted calculator).
 
Total peanut gallery over here, since my little niche represents a market share of limit approaching zero, but for airgun hunters LPVOs with adjustable parallax down to 10 yards are kind of the perfect scope. Now... most of us aren't going to pay March Shorty money to slap on top of a hunting airgun, but still.

What is unfortunate is that even 100yard fixed parallax is a problem at squirrel hunting ranges. As a for instance, even with the BDC reticle the 5x Vortex prismatic would be a great airgun squirrel optic, but the parallax error is too gnarly at 10 or 20 yards to work when you're trying to hit a 1 inch target quickly before it moves.

Again, peanut gallery.
 
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Total peanut gallery over here, since my little niche represents a market share of limit approaching zero, but for airgun hunters LPVOs with adjustable parallax down to 10 yards are kind of the perfect scope. Now... most of us aren't going to pay March Shorty money to slap on top of a hunting airgun, but still.

What is unfortunate is that even 100yard fixed parallax is a problem at squirrel hunting ranges. As a for instance, even with the BDC reticle the 5x Vortex prismatic would be a great airgun squirrel optic, but the parallax error is too gnarly at 10 or 20 yards to work when you're trying to hit a 1 inch target quickly before it moves.

Again, peanut gallery.

There is a more affordable 1-10x LPVO coming to market later this year that has side focus. I fully intend to put it onto my Leshiy2.

ILya
 
I think that many who want side focus on an LPVO also don’t want to pay the weight penalty, as evidenced by the moaning at the 24oz 2-10x32 Leupold thread.

For perspective, the Razor 1-10 is 21.5oz. If there’s that much moaning over 2.5oz…I dunno. Optimizers like to bitch (I speak from experience).

But what are the hard numbers, the misses we are going to have without side focus / parallax adjustments? Theory is not working here.

Calc from a 1-10x24mm Vortex Razor Gen III that is factory set at a 150yd parallax & based off of a Leupold dude in a RO podcast:

(You might have to turn your phone sideways to best read the table below. Also, earlier versions make the parallax error look worse b/c I suck at math. Scopes with larger objectives will have larger potential errors.)

DistanceMax reasonable error if taking your time
(a guess, half of Max Reasonable in-a-hurry)
Max reasonable error in-a-damn-hurry
(a guess, half of Max Stupid)
Max Stupid Error
(looking through scope diagonally, lots of scope shadow, barely being able to see center crosshair, sliver of light. NOT A GUESS, FROM RO PODCAST.)
AKA: Mr. Sniper LPVOAKA: “Shit I’m getting shot at!”AKA: Fell down a well, upside down, one handed
150yds000
3003mm / 0.1181102362”lol or ~ 1/8”6mm / ~0.25”12mm / ~0.5”
4506mm / ~0.25”12mm / ~0.5”24mm / ~1.0”
6009mm / ~0.35”18mm / 0.71”36mm / 1.4”
75012mm / ~0.5”24mm / ~1.0”48mm / 1.9”
90015mm / 0.6”30mm / 1.18”60mm / 2.4”

I suck at math, so I took this from about 25min at this link (Dave @Feniks Technologies / @Dthomas3523 was on this too)



For those who don’t want to bother listening, the Max-Fell-Down-A-Well parallax error is calc like this: parallax is set at X yds. For every X yds further, add 1/2 of objective diameter.

Perhaps my assumptions of “reasonable error” are off here, but even at Max Stupid Error at 600yds I can deal with a potential 1.4” error when shooting something as small as a damn prairie dog.

Note that I often shoot pdogs from a well’s bottom, upside down, and with one hand.

This isn’t even getting into hyperfocal stuff, which you can’t typically find on a scope’s specs without calling the manufacturer. I’m hazy here.

To sum up:
  • Would side focus be nice? Yes.
  • Would lockable side focus be better? Yes.
  • Do these things add weight? Yes.
  • Will the same people who demand these features bitch and moan about weight? Yes.
  • Does it really matter, from an “hitting what I want to hit” perspective? No*
Usually, the more inconsequential an argument’s outcome, the more strident the opinions.

Edit: in that podcast it was also noted that contrary to popular belief, parallax error affects people’s emotions more at close ranges, like 100 yds. I think the example was if you left your scope set at 750yds and shot at 100yds, you’d notice.

The actual error isn’t a huge number, but errors magnify their importance in your brain at close ranges. Why? Because you want the tightest group to see how good your barrel (& skills) are.

But, of course, if you’re off at 100yds and you base a lot of your dope on that, then a small error here might get magnified. I can’t figure out the potential errors at 100 (only 50yds less than the parallax is set at) but my intuition tells me it’s not gonna be much. Could be wrong, though.

*Excepting you benchrest fags lol

Can you do these calcs for, say, 100 yard fixed parallax, shooting at 25 yards?

Again, it's a hyper niche market that no builder would care about, but for small game pesting with air rifles *really* small targets at very close ranges is the order of the day.
 
Can you do these calcs for, say, 100 yard fixed parallax, shooting at 25 yards?

Again, it's a hyper niche market that no builder would care about, but for small game pesting with air rifles *really* small targets at very close ranges is the order of the day.
Here's one of the online calculators if you want to play around with it.

 
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Here's one of the online calculators if you want to play around with it.

Hey, thanks for the link.

Was kind of what I suspected --- better part of a half inch at 20 yard for something with fixed parallax at 100.

Squirrel head is about an inch and a quarter, and you arent shooting off a bench --- usually leaning against a tree if you're lucky.

So yeah, silly as it sounds, matters a bunch.
 
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