I just returned from an eye exam in which my optometrist measured my IPD at 63mm. This came somewhat as a surprise as I typically find that my IPD settings on my binoculars fall in the +/- 65mm range. Can one extrapolate their IPD to where they set the IPD on their binoculars, or is there an inherent difference given the mechanics of the optical device (the binocular)? I quickly set one of my binos to 63mm and the field of view appear vignetted and too restrictive - or am I just unused this 'proper' setting?
I would appreciate any experience or feedback.
Hello Dug-Mac;
I have done a little IPD testing and posted about it some time back. There was a lot of good feed back. Look at http://www.birdforum.net/showthread...3&highlight=ipd
There is some indication that measuring ones IPD with a ruler tends to be 1 or 2 mm on the wide side. Also, when using large exit pupils and adjusting from the outside in, there is some tendency to set bins wide. Did your examiner use a ruler or machine (pupilometer)?
Try setting IPD while looking at far distant point.
If you don’t find any help in the referenced thread, we may try something else.
Best
Mine were measured with a ruler at 65 but I find I tend to manually adjust slightly wider at 66mm (assuming the calibration of the bins is good!). I think part of that is people (well, me) dislike vignetting more at the outer edges of the field than at the inner edges.
The easiest way to measure it accurately yourself (and some of the fancy new pupilometers just the same idea) is to photograph your face with a digital camera with a ruler held to your forehead whilst looking at a distant object. Then you can use the image of the ruler to make a more accurate measure when you view the image on a computer.
The latter is important e.g. a 65mm distant IPD like mine is about 62mm IPD at reading distance. So trying to measure it in a mirror yourself can lead to errors too.
I've seen at least one paper point out the significant errors that can creep in though the ODs seem to think they're all perfect at making an accurate measurement!