-
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
How to set IPD accurately? (1 Viewer)
- Thread starter tenex
- Start date
Hermann
Well-known member
WJC
Well-known member
Wow! I had no idea this topic would be of such interest.
The main reason for measurements in PD (which takes the centerline of the nose into consideration), as opposed to IPD (which doesn't) is the more critical nature of prescribing "progressive" ophthalmic lenses vs. bi-focal or single-vision lenses. The "sweet spot" on progressives is very narrow when compared to the other two. Thus, the prescription must be more precise.
And, of course, those who feel the urge to keep staking these ophthalmic BBs can follow the idea that the PD for those who need glasses for READING would be narrower than for those using binoculars for ASTRONOMICAL OBSERVATIONS. And so it goes. Although all my binoculars are set correctly, I have never bothered looking at the numbers and see no reason to do so. When it's right, you'll know it. When it's not right, you'll know it. And, if you're more than a second grader, you'll intuitively know in which direction to move the setting. Small differences will be taken care of through your spatial accommodation.
Bill
The main reason for measurements in PD (which takes the centerline of the nose into consideration), as opposed to IPD (which doesn't) is the more critical nature of prescribing "progressive" ophthalmic lenses vs. bi-focal or single-vision lenses. The "sweet spot" on progressives is very narrow when compared to the other two. Thus, the prescription must be more precise.
And, of course, those who feel the urge to keep staking these ophthalmic BBs can follow the idea that the PD for those who need glasses for READING would be narrower than for those using binoculars for ASTRONOMICAL OBSERVATIONS. And so it goes. Although all my binoculars are set correctly, I have never bothered looking at the numbers and see no reason to do so. When it's right, you'll know it. When it's not right, you'll know it. And, if you're more than a second grader, you'll intuitively know in which direction to move the setting. Small differences will be taken care of through your spatial accommodation.
Bill
Last edited:
It might depend on the size and configuration of the individual nose.
Not Bill Cook!
In his post #23 above he says that setting it is intuitive. When it is right you will know it and when it is wrong you will know it.:t:
Bob
tenex
reality-based
I'm not trying to make something simple complicated. I just don't find that my experience always corresponds to those "Binoculars for Idiots" photos Dennis posted. There's often a range of settings where it looks more or less like a single circle to me... but if I'm not in the middle of that range, with roof prisms anyway, I'll soon get annoying little blackouts. Maybe I just need a systematic approach to eliminate them as Alexis suggested.
WJC
Well-known member
Get back there and put a couple of exclamation points after "Nothing"; the underlining wasn't enough. :cat:
Bill
It was a general statement, and it was not directed at you or anyone else in particular.
It is a personal observation based on a lifetime of experience, similar to "All behavior offends someone."
WJC
Well-known member
Hey, Bob:
If you're pickin' on me ... stop it. You're inviting folks who aren't qualified to do so. Although, I CAN take it ... I raised 3 teens. Speaking of which, I think the people who make those "baby changing tables" for restaurants should be sued for fraud! I had my first son on many of them over the years and they didn't work ... not once. I was hoping for a puppy. But the only thing that got changed was a poopy diaper! :eek!::cat:
Bill
Torchepot
Well-known member
I've never made a study of this but I think some binoculars are more forgiving of slight misalignment of IPD setting than others. I've noticed on occasion when trying other people's optics that some roof prism bins with a narrow field of view are a bit more tricky to get right while my old Porros 10x50s, which got passed around a fair bit before their premature demise, were very easy to reset - maybe they had more latitude for being slightly out?
Any particular binoculars that you find more problematic tenex?
Any particular binoculars that you find more problematic tenex?
Kevin Conville
yardbirder
No kidding, gentlemen. Not exactly brain surgery. Alexis, you're making me laugh! You mean setting IPD isn't 3 dimensional chess?
Last edited:
He certainly encouraged us to continue in the same way with our expenditure which is primarily on holidays to Scotland with a bunch of binos and cameras as often as we can manage it.
Lee
LOL I think you mean 'until back in the black'. Don't give up the day job to become an accountant!
Lee
Some of my friends wonder who in their right mind visits a website to discuss binoculars.
Lee
Crikey I am struggling with this Peter. Lets look at my own example. I have one eye fractionally closer to the midline of my face than the other, so my two PDs are unequal as in your example. Add them together and I get 58.5mm whereas from my own measurement of how I set my bins I get 58mm so ignoring this minor difference these are in agreement. With my binos set to 58mm they align with my eyes just fine even though I have unequal PDs and if we can enter the world of fantasy for the moment and imagine my nose has disappeared, it wouldn't matter where my eyes were on my face, providing the total IPD remained as it is now, I would still be able to move the binos so as to look through them just fine.
The difference between spectacles and binos is that specs have to sit on your nose so the lenses have to be the right distance from the nose to each side and these distances need not be equal. Your binos are't limited to this fixed position so the total of the two PDs added together to give the IPD can be satisfied by the bino being set to this IPD and when lifted to the eyes being a little to the left or a little to the right of the centreline of the face. Your binos don't need to know where your eyes are, just the distance between them.
Lee
The-Wanderer
Well-known member
And how much did you pay for this advice? My 'financial' acumen is way low, and I could've suggested that!
LOL. I am sure you could.
We have known this bloke for more than 30 years and he has taken care of our retirement investments very, very, very well indeed.
Lee
