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Rifle Scopes Parallax vs Image Focus

Correct.

And if anybody out there reading this is a photographer and works with SLR cameras, then this should all make sense and actually be rather elementary. This is also why I PREFER scopes with very narrow depth of field. It makes it easier to eliminate parallax and find the very center of that focal field for a perfectly focused target. Wider depth of field makes the scope more forgiving for shooting multiple targets and different distances without having to touch your parallax (sort of ). But it also means it's harder to nail perfect target focus for zero parallax.

Personally, I have no need to engage multiple targets at difference distances super fast. I do a PRS-style match here or there, so it's not needed quite as much for me. And I'm not engaging live targets in combat. So I can take my time and readjust parallax when needed.
I think your preference for a narrow depth of field is reflected in some optics like March. Not
as easy to use, but allows absolute elimination of parallax error and max precision. Some
folks seem to mistake ease of use and large depth of field for better design: not so. Horses
for courses....
 
I think your preference for a narrow depth of field is reflected in some optics like March. Not
as easy to use, but allows absolute elimination of parallax error and max precision. Some
folks seem to mistake ease of use and large depth of field for better design: not so. Horses
for courses....

Yeah that's why some people like to rock their head back and forth to check for apparent movement between target and reticle. Me? I just like to adjust the parallax control until the target is sharp.
 
Some great info in this thread. I’d like to throw two cents in the bucket, being the human
eyeball . Past few days have been spent at the range for 10 hours. Yesterday I became a
bit dehydrated and found I was missing my favourite 2.5 inch practice gong @ 500 meters,
when making a perfect wind call. Suspected aero jump or mirage, but reticle was a bit
blurry so Iwound diopter out a bit and elevation on target was perfect again. Wonder
how many people blame the solver when it’s actually parallax error, mirage displacement
etc?

Today I made sure I had enough water, and had to wind the diopter back in to yesterday
mornings’ setting. So despite same scope, rifle, ammo, target and (similar) wind conditions,
the biggest variable was me and my dehydrated eyeball.....

I believe this is why S&B will state in some manuals that when behind the rifle scope for long periods of time to readjust the diopter occasionally.
 
Some great info in this thread. I’d like to throw two cents in the bucket, being the human
eyeball . Past few days have been spent at the range for 10 hours. Yesterday I became a
bit dehydrated and found I was missing my favourite 2.5 inch practice gong @ 500 meters,
when making a perfect wind call. Suspected aero jump or mirage, but reticle was a bit
blurry so Iwound diopter out a bit and elevation on target was perfect again. Wonder
how many people blame the solver when it’s actually parallax error, mirage displacement
etc?

Today I made sure I had enough water, and had to wind the diopter back in to yesterday
mornings’ setting. So despite same scope, rifle, ammo, target and (similar) wind conditions,
the biggest variable was me and my dehydrated eyeball.....
Yep, dehydration is a real concern. Especially when it's not that hot outside, it's easy to forget to drink when you're not sweating alot.
 
Now I always check it with headmovement (when I am in a stable position) and dont go just by image quality.

I think this is a mistake many shooters make - thinking that "in focus" automatically means parallax free, I've had my share of setting side focus for an image that looks good but parallax ends up being quite wobbly. This is where fine tuning the diopter can help out in some situations, I've seen parallax settle down with minor tweaks to the diopter - it's not just for setting reticle focus. I think ILya has some videos on this but I'm too lazy to look them up right now o_O :LOL:
 
So a quick follow up, earlier I stated I need to check the diopter setting more and really spend some time with it, to get my Hensoldt 6-24x72mm parallax free, which I was never successful at.

During range setup I happened to look through the scope with my left eye, holy crap it was like a new scope bright colors etc..., turns out I have a small cataract exactly right in the middle of my right eye. I have always had 20/12 or 20/15 vision with that eye, now it is 20/30 but it explains everything I was perceiving.....I thought the scope was failing and was about to send it back for repair/inspection.

So if someone else is having similar problems, you can get cataracts early, I am just over 50 years old and frankly did not notice them at all, even now that I know it is there it does not bother me except for shooting.

Getting new lenses...after the surgeries are done I will then try to se the scope up again.

Hopefully if someone else is reading this with similar problems they will get their eyes checked.
 
Not yet another few weeks before surgeries are done, going to try the new lenses that are supposed to give you a little bit of near vision. It takes a while, they do the non dominant eye first...then make sure you recover, then the dominant eye.
 
Not yet another few weeks before surgeries are done, going to try the new lenses that are supposed to give you a little bit of near vision. It takes a while, they do the non dominant eye first...then make sure you recover, then the dominant eye.
Unless you are extremely nearsighted (ahem, like me). I've got early cataracts too, in both eyes. If they did just one of my eyes, my ophthalmologist said that my brain would not be able to reconcile the two different sized images projected on my retinas (one low Rx, one high).

Boy, that's going to be fun, both eyes done at once.
 
So to finally report back with all my results...

Both eyes are done, I went with new lenses in my eyes by Bausch and Lomb called "Crystalens" (these lenses cost more but I highly recommend them) They let you focus up close and far using your original muscles that focused your eyes when you were young, the eye people call this accomadation. For you young guys not a problem you are likely to see until age 45-55...but as you age your lenses typically harden so you are then not going to be able to focus up close at some point, Crystalens fixes that problem.

Anyway my eyes are working great! Got almost all the parallax out of the scope...there is still a little an inch or two at 1000yds, which is still irritating, but if I back my eye off the scope to get just a touch of vignetting equally around the edges my eye is centered in the optic path. A bit like shooting iron peep sites but much easier....

Anyway shooting 1000yd FCSA 50BMG matches, now that I can see doing much better :)
 
So to finally report back with all my results...

Both eyes are done, I went with new lenses in my eyes by Bausch and Lomb called "Crystalens" (these lenses cost more but I highly recommend them) They let you focus up close and far using your original muscles that focused your eyes when you were young, the eye people call this accomadation. For you young guys not a problem you are likely to see until age 45-55...but as you age your lenses typically harden so you are then not going to be able to focus up close at some point, Crystalens fixes that problem.

Anyway my eyes are working great! Got almost all the parallax out of the scope...there is still a little an inch or two at 1000yds, which is still irritating, but if I back my eye off the scope to get just a touch of vignetting equally around the edges my eye is centered in the optic path. A bit like shooting iron peep sites but much easier....

Anyway shooting 1000yd FCSA 50BMG matches, now that I can see doing much better :)
So they actually implanted glass lenses inside your eye? What was recovery time?
 
So to finally report back with all my results...

Both eyes are done, I went with new lenses in my eyes by Bausch and Lomb called "Crystalens" (these lenses cost more but I highly recommend them) They let you focus up close and far using your original muscles that focused your eyes when you were young, the eye people call this accomadation. For you young guys not a problem you are likely to see until age 45-55...but as you age your lenses typically harden so you are then not going to be able to focus up close at some point, Crystalens fixes that problem.

Anyway my eyes are working great! Got almost all the parallax out of the scope...there is still a little an inch or two at 1000yds, which is still irritating, but if I back my eye off the scope to get just a touch of vignetting equally around the edges my eye is centered in the optic path. A bit like shooting iron peep sites but much easier....

Anyway shooting 1000yd FCSA 50BMG matches, now that I can see doing much better :)
50 bmg and proper eye surgery recovery.......the concussion and sinal pressure from that weapons platform should be greatly considered. That rifles recoil and concussion had caused retina detachment in shooters. Just saying.......be careful.
 
Lenses, no they are not glass some special flexible plastic of some sort....this is the normal treatment for cataracts, as I understand it somepoint they used cadaver lenses, did not fact check that though. (google key words "cataract surgery" explains it all way more clear than I can)

I can not comment on retinas, opposite end of the eye and no issue there for me....I did ask my surgeon about lens replacement and concussion. His take was an over-pressure/concussion that would do enough damage to dislodge the lens would cause far more than just eye damage. The new lenses are held in the same way as the original I was born with, so the replacement is as robust as the original.

Recovery time, that varies depending on what your going do, for shooting 50's I did the surgery in the fall and did not shoot until the spring. For driving reading there was almost no no recovery time but a few weeks of taking special eye-drops. I was driving within a day or two.

For flying, since these lenses are "new and special" the FAA made me wait 90 days. If they had been the standard cataract lens replacement then it would have been only a week or less.

Swimming was not allowed for a month or something like that as well.

Results 20/15 maybe 20/10 on a good day far vision which is what I had when I was young, close up keeps improving and can improve up to 5 years post surgery as. For now around 20/30-40 or so depending on lighting. Shooting flying and reading all good, still need cheaters for things really close and really small.
 
Lenses, no they are not glass some special flexible plastic of some sort....this is the normal treatment for cataracts, as I understand it somepoint they used cadaver lenses, did not fact check that though. (google key words "cataract surgery" explains it all way more clear than I can)

I can not comment on retinas, opposite end of the eye and no issue there for me....I did ask my surgeon about lens replacement and concussion. His take was an over-pressure/concussion that would do enough damage to dislodge the lens would cause far more than just eye damage. The new lenses are held in the same way as the original I was born with, so the replacement is as robust as the original.

Recovery time, that varies depending on what your going do, for shooting 50's I did the surgery in the fall and did not shoot until the spring. For driving reading there was almost no no recovery time but a few weeks of taking special eye-drops. I was driving within a day or two.

For flying, since these lenses are "new and special" the FAA made me wait 90 days. If they had been the standard cataract lens replacement then it would have been only a week or less.

Swimming was not allowed for a month or something like that as well.

Results 20/15 maybe 20/10 on a good day far vision which is what I had when I was young, close up keeps improving and can improve up to 5 years post surgery as. For now around 20/30-40 or so depending on lighting. Shooting flying and reading all good, still need cheaters for things really close and really small.

Heavy recoil and associated concussion both via direct recoil to the body and aerial shock from the muzzle blast are potentially dangerous to the retina, not really to the lens in the eye. These issues are exacerbated by aging effects and various diseases, like diabetes and a few others.

ILya
 
Heavy recoil and associated concussion both via direct recoil to the body and aerial shock from the muzzle blast are potentially dangerous to the retina, not really to the lens in the eye. These issues are exacerbated by aging effects and various diseases, like diabetes and a few others.

ILya
In addition, there is a common occurrence after cataract surgery called Posterior Vitreous Detachment (PVD) and has to do with the implanted new lenses being on the order of 1 mm thick while your natural lenses were more like 3 mm thick (please don't quote me on the exact measurements...point is that implanted lenses for cataracts are thinner than your natural ones).

As we age, the vitreous jelly in our eye becomes more liquid and shrinks. As it does so, it tends to pull away from the three attachment points at the back of the eye and this is called PVD. This can happen to anybody but is often precipitated by cataract surgery as a couple of mm of support in the front is removed with the lens replacement.

Then there is aging, cataract surgery, and recoil....all sort of a PVD perfect storm.

Not everybody gets large floaters from PVD but it is common including a round ring floater called a Weiss Ring which is from where the vitreous jelly attached to the location of the optic nerve. Single flashes of white at the far periphery of your vision is also common. Both the floaters and the flashes get much better over time and treatment for PVD floaters is commonly viewed as worse than the problem. If interested, lots of stuff can be found on the net about PVD.

The really important thing, per my eye surgeon, is to be able to distinguish normal PVD and a detached or torn retina. I was told to memorize these three symptoms and if I observed any of the three to come in on an emergency basis as its a torn or detached retina:

1. Snow Globe effect - just what it sounds like...looks like snow floating in your vision
2. Repeated flashing light in the center of your vision (vice PVD which is one flash and in the far periphery)
3. Curtain...looks like a curtain coming down over part of your vision.

I got PVD symptoms 6 months after my first cataract surgery. Rarely notice floaters at all and very occasionally see at night a flash of light in my far outside periphery when I cut my eyes (think looking in the passenger side mirror when driving at night). It freaked me out but over time become a nothing burger.

I've had the other eye done and so far no PVD.

I'm very glad that I got cataract surgery, worth it by far, and I'm back to 20/20 in both eyes at 70 y.o.

But I think we need to recognize that there really isn't any free rides in life and there is always some sort of degradation or side effect from surgery.
 
But I think we need to recognize that there really isn't any free rides in life and there is always some sort of degradation or side effect from surgery.


YEAH.... SIDE EFFECTS from my surgery.

No deductible for my surgery on both eyes, but I'll still need glasses, of course the 1st thing out of my mouth is then why bother.


They of course tell me if I'd like my vision back to where it was when I was 30 where I can see distance and up close, that'll be an upgrade of $6,000 per lens and of course I doubt if anybody ever gets just one so it's a $12,000 deductible.


They did take pity on me, I told my doc I was a photgrapher, turned out he was too, sent him some of my pics, the guy was sincere and told me he'd get me back decent, so he had them knock off a discount for the upgrade, which kept my wallet from having a stroke.


Felt good about the fact that some docs aren't all about golfing and money bags.


At 74, I don't plan on shooting any of my 000 buck out of my shotguns any time soon.
 
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YEAH.... SIDE EFFECTS from my surgery.

No deductible for my surgery on both eyes, but I'll still need glasses, of course the 1st thing out of my mouth is then why bother.


They of course tell me if I'd like my vision back to where it was when I was 30 where I can see distance and up close, that'll be an upgrade of $6,000 per lens and of course I doubt if anybody ever gets just one so it's a $12,000 deductible.


They did take pity on me, I told my doc I was a photgrapher, turned out he was too, sent him some of my pics, the guy was sincere and told me he'd get me back decent, so he had them knock off a discount for the upgrade, which kept my wallet from having a stroke.


Felt good about the fact that some docs aren't all about golfing and money bags.


At 74, I don't plan on shooting any of my 000 buck out of my shotguns any time soon.
Did you get multi-focal lenses? If so, any issues w headlights at night? Glare and/or starbursts?
 
I got the torics where they rotate them lining them up to correct for astigmatism, so I can see what I'm typing/the dash on my car w/excellent distance vision.

The torics correct for both the cataracts and my astigmatism. If memory serves, I think Carbonbased has had the same surgery.

Closer than 9-10 inches will use glasses which means I'm good for everything except for the extra small print which to me is fine.

Had a 2nd surgery on the left eye because either the toric had moved or wasn't rotated all the way into position (30 degrees off). I looked up at the moon on a dark night, and could see a thick ass beam of white light going all the way across the field of vision in my left eye.

EXACT same thing as when watching a movie shot w/cinemascope lenses where the headlights of a car point straight at the camera and a shaft/beam of light goes all the way across the screen from the headlights.

Luckily they got the toric loose from the connective tissue that had grown around it from the first surgery and were able to rotate it another 30 degrees to correct for the astigmatism so that the vision in that eye is fine.

No glare or starbursts around light sources @ night.


What's been discussed here was the cautionary drummed into me by my surgeon; what he said was essentially that you don't have a brand new pair of eyes, you're an old man w/old eyes which have been partially repaired so you're getting a chance to get a good deal of your vision back, but everything else "in there" is getting delicate, so you have to be careful/thankful for what you're getting back, and most importantly take care of yourself or you can easily lose what we just gave you.
 
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I got the torics where they rotate them lining them up to correct for astigmatism, so I can see what I'm typing/the dash on my car w/excellent distance vision.

The torics correct for both the cataracts and my astigmatism. If memory serves, I think Carbonbased has had the same surgery.

Closer than 9-10 inches will use glasses which means I'm good for everything except for the extra small print which to me is fine.

Had a 2nd surgery on the left eye because either the toric had moved or wasn't rotated all the way into position (30 degrees off). I looked up at the moon on a dark night, and could see a thick ass beam of white light going all the way across the field of vision in my left eye.

EXACT same thing as when watching a movie shot w/cinemascope lenses where the headlights of a car point straight at the camera and a shaft/beam of light goes all the way across the screen from the headlights.

Luckily they got the toric loose from the connective tissue that had grown around it from the first surgery and were able to rotate it another 30 degrees to correct for the astigmatism so that the vision in that eye is fine.

No glare or starbursts around light sources @ night.


What's been discussed here was the cautionary drummed into me by my surgeon; what he said was essentially that you don't have a brand new pair of eyes, you're an old man w/old eyes which have been partially repaired so you're getting a chance to get a good deal of your vision back, but everything else "in there" is getting delicate, so you have to be careful/thankful for what you're getting back, and most importantly take care of yourself or you can easily lose what we just gave you.
Cool. Yeah, Toric are not the same as multi-focal and it is the later that seem to have a significant frequency of issues with headlights and similar point light sources.

I only have a very minor astigmatism in one eye and Dr assured me that I wouldn't notice any difference between regular lenses and one that would correct for this very minor defect.

I'm 70 and so perhaps like yourself, I did not resume shooting until all restrictions were lifted. Just not worth endangering my vision.


Cheers
 
Cool. Yeah, Toric are not the same as multi-focal and it is the later that seem to have a significant frequency of issues with headlights and similar point light sources.

I only have a very minor astigmatism in one eye and Dr assured me that I wouldn't notice any difference between regular lenses and one that would correct for this very minor defect.

I'm 70 and so perhaps like yourself, I did not resume shooting until all restrictions were lifted. Just not worth endangering my vision.


Cheers



Being in your 70's is GREAT!!

There isn't anybody in the cemetery who wouldn't trade places w/either one of us in hot second.
 
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Ok holy crap the torn retina symptoms I would notice...wow that is some scary sounding shit! But also VERY good to know thanks!!

I am "only" 56, my cataracts were likely early for me due to so much high altitude flight, also in the Navy I was bad about wearing a tinted visor...half the time I had the stinking thing up vice down where it belonged. And I continued to be bad a as an airline pilot not wearing sunglasses...anyway those things likely/maybe accelerated the onset of cataracts. The cool thing is these lenses have built in UV protection :cool:

I went with the accommodating/focus-able lenses out of all the options the most expensive....seems to always work that way. Anyway no side affects for me at all and no complaints. I had to pay for the upgrade, my cataracts were mild but since I needed 20/20 vision to work insurance covered me for everything except the upgrade, if I did not need the surgery to work they would have delayed until they got worse.

ILya of course has it correct, diabetes would not be good for your eyes in any way, also VERY bad for a flying career....keeps me doing the PT and sort of eating correctly...

50BMG, I am one of the youngest guys competing...most of the guys I shoot with are late 60s at the youngest, have not heard of any of them having retinal problems, don't read much into that, its not a scientific study or large sample size by any stretch...
 
Well, I’m 53 (but apparently 85yrs old inside) and as @Convex mentioned, I had toric lenses installed late Jan of this year. I had the distance set in a monovision fashion, which means one eye is set for close up and the other for distance. About 20% of the population’s brains can merge the two images together. Works well for me.

Recently, I also had double vitreous detachment, which left me with Jupiter-sized floaters, one in each eye. I already had millions of small floaters, but now it’s just out-of-control stupid.

Was walking on pins and needles and not lifting a thing due to my dad having three retina detachments after his surgeries 30 yrs ago. Didn’t matter, as I had a retina detachment about four weeks ago. Good times.

I caught it very early. Noticed I suddenly lost a tiny bit of my bottom peripheral vision in one eye and immediately called the doctor at 8pm at night on a Sat.

He had me come in at 9am on Sunday and lasered around the entire retina’s circumference and injected a gas bubble to float up and press against the detachment in order to make it stick against the back of the eye. You see, the bottom of your vision is actually the top of the retina as you see upside down and your brain flips it.

Outpatient procedure. With lots of needles. Yeesh.

I was instructed to sleep sitting straight up, like in grade school lol. Didn’t make it the whole night…impossible. Then the next day he lasered the detached bit. So it was a success.

But I’ll see that damn black giant gas bubble at the bottom of my vision for another month, at least, until it gets absorbed by my body (2 months total). The bubble reflects light so I also see lots of internal flare plus the Jupiter floaters, and that eye’s vision is fuzzy due to the iris being dilated (see below).

Can’t fly with a gas bubble in the eye, nor can I have certain anesthesia until the gas bubble goes away. Or “pop” goes the eyeball 🎶

The laser procedure caused my eye to be massively dilated for 6 months, and just in case I need the other “good” eye lasered in a month to hopefully prevent that retina from detaching.

I guess if one eye goes, the other is sure to follow.

So then I’ll have two massively dilated eyes for months and months. No shooting for me for most of this year…last time I picked up a rifle was in January, pre-cataract surgery.

After that I’ll probably need the floaters either lasered (like Star Wars) or eliminated via traditional surgery (suck bad juice out, put good juice back in lol).

Before the surgery I was nearsighted at -10 / -11.

I do wish they made cataract replacement lenses physically bigger to mimic the biologic lenses so the eye’s internal volume wasn’t reduced. I was told, as someone above mentioned, that this is a main reason for vitreous detachment which, in people like me, often leads to a retina detachment.

I guess I’m lucky because I can still see?

Moral of the story is: Even if you don’t see a shower of floaters, pay attention. The doc was amazed I had detected the detachment. Earlier detection = better.

If the retina really falls off bad then you need major “open-up-the-eyeball” surgery, which my dad had three times and man, that is noooooo good. In his case, during one surgery some noob nicked an eye muscle and then he was sorta cross-eyed for some time. Ugh.

Sorry for being so wordy. Maybe this will help someone in the future.
 
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Don't do any lifting Carbonbased while UR healing up, be careful and don't take any chances where U might take a "spill".

One of my neighbors is too old to be getting up on a ladder and did it anyway and took a spill.

You're way younger than he is but U don't need any hard knocks.


Good luck Sir.


Surgeon told me while UR healing up, don't lift anything heavier than 10 pounds, hell, that's everything except eating dinner.
 
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Don't do any lifting Carbonbased while UR healing up, be careful and don't take any chances where U might take a "spill".

One of my neighbors is too old to be getting up on a ladder and did it anyway and took a spill.

You're way younger than he is but U don't need any hard knocks.


Good luck Sir.
Thanks man. Don’t worry, I’ve been Ultra Puss™ ever since late Jan after my cataract surgeries. Lifting too much was the mistake my dad made after his cataract surgeries and I wasn’t about to repeat it.

And you should see me scuttle away like a hermit crab when I am unexpectedly around anyone hitting a ball or swinging a stick. Lol. I’m not even supposed to jog or use vibrating power tools.

After all of this I’m going to have the muscle tone of a 100 yr old grandma! Regarding shooting, I’ll be so out of practice I won’t be able to hit the broad side of a barn.
 
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