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help with moving IPD scale (1 Viewer)

gammaray

New member
Hello there

I am very new to binoculars, bought a pair the other day second hand and wanted to make sure I adjust them properly.

One thing i noticed is that the IPD markings are on a black plastic washer, held with a screw on top of the brass screw which keeps the eye pieces in place.

The IPD markings are 60 and 70, with a few gradings in between.

Now one thing that confuses me is that the washer with the IPD markings is not stable, it spins really easily around the screw. And this definitely makes it inaccurate. So i was wondering whether i should tighten that screw - and if I do so, where do the markings have to sit?


On another note, is it really important to have this sorted, or can I simply adjust the eyepieces according to whatever feels comfortable for me, regardless of what the markings indicate?

From what I have noticed, the washer with the IPD scale on it just covers the brass screw, so whether or not I set the markings in the correct place it should not really affect how the binocular functions.... Am I on the right track?

Thanks guys.
 
I guess the IPD scale might be of some use if a pair of binos is passed between people who already know their IPDs. In practice I've almost never noted it or used it as it only takes a second or so to adjust once it's up to the eyes. The exception is one pair of large porros I have with a stiff hinge. It has unusually large oculars and exit pupil, and is a little tricky to centre the view, so if someone else has used it, I can reset it easily.

I'd just tighten it down to stop it falling off. If you want to reset it, I imagine it would only take moments with a ruler and a screwdriver. Just measure between the same points at the edge of the lenses or something similar, turn the ring to the same value and tighten up.

David

PS. Gammaray, welcome to the forum. :t:
 
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thank you! that is good advice, i will do so.... but could you please elaborate regarding how to measure? i am a complete beginner, so do not know about measuring binoculars.

what do i have to measure? like from the edge of one lense to another? like move the eye pieces towards each other and put the 60 mm mark when i have them at 60 mm distance, then tighten with the screw?

thanks again!

vlad
 
Vlad,

Ideally you are measuring from the centre of one ocular lens to the centre of the other, but in practice you can't to that with any accuracy without instruments. It's much easier to use another point like the right hand edge of each lens, or the eye-cup edge or what ever is convenient. Just use a ruler rested on the oculars so that the marked edge is in line with the centres of both lenses and read off the distance.

Typically most binos have an IPD range of about 55 to 75mm. The dial might have 60 and 70 marked, and one or more marks in between. What ever the value is in millimetres from the ruler, set the dial the same. It's not necessary to preset the IPD, just match the value.

Hope that helps,

David
 
You can use the trial and error method to get an approximate measurement.

Just sit in a chair, relax and look at an object about 100 feet away and fiddle around making the distance between the binocular's tubes wider or more narrow until you get what you think is the widest, most comfortable view. Then memorize that number on the scale. You can make more minute adjustments from there as you see fit when you reopen the binocular for use.

If you ever get a roof prism binocular this is the way you will have to do it all the time anyway because they don't have IPD scales.

Bob
 
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