What Are Eye Relief Binoculars

How To Use Binoculars With Glasses And Save Your Lifetime Opportunity

As a mad bird watching, distance no object, drop everything and drive now sort of person it was with enthusiasm that I moved to the US. I knew this would give me ever greater opportunity to spend my spare time twitching.

It took a couple of years to settle in and then I started to get to know some really fabulous places to go and pursue my passion. However I was always so consumed by the moment, that drop everything and run moment that I overlooked simple but very important things.

Here is an account of how I learnt the hard way.

Missed Opportunity

So after 15 days and nights of patience there it was. Just 400 yards in front and I saw the head bobbing. Finally this was the chance I had been waiting for. Quickly I removed my glasses raised my binoculars to my eyes. It was this moment that defined my ignorance of how to use binoculars with glasses.

This moment, one I had waited so long for vanished in a second. By the time my bins were at my eyes and focused the bird was gone. The Gunnison sage-grouse was one of my top 5 ‘lifers’ and this was my last day.

But that was it – opportunity gone due to the delay in switching from my glasses to my binoculars.

The Gunnison sage-grouse is a bird that disappears with the slightest sound. Now others were turning up at the Waunita Lek so I knew it was too late and my chance was gone.
Eye Relief Binoculars Sage Grouse

Contemplation

On the way home from Colorado I knew it would be a year before I could return. It was painful my ignorance of using binoculars that work with glasses had cost me 15 days of twitching. I had an overnight stop on my return journey. I decided to do what I should of done years ago. Find out which are the best binoculars to use with glasses.

Quietly I sat on my bed and started the search using my iPad. Of course Google was the obvious choice. Quickly I found a number of good personal resources on the subject. One had the heading ‘how to look through binoculars with glasses’.

What I realized quickly is that the subject is more complicated than I thought. People for example flatten their frames or get their glasses adjusted and do all sorts of DIY stuff. Then there are different eyeglass solutions and contact lenses.
Long Eye Relief Binoculars

One thing I saw regularly is that there are specific binoculars associated with the term eye relief. Being a twitcher I had heard this phrase before. It was mainly in passing conversations but I had not bothered to look into it.

It also became apparent that wearing contact lenses is not an ideal solution. This is due to the way binoculars are used – as in long periods of staring. Dry eyes and hazy vision are common issues.

The way round this was to purchase a set of binoculars that offer long eye relief.
Field Of View

The crucial aspect here is the ability to have your eyes further back from the lens. Then you also need to have a wide field of view. This does two things, it relaxes the eyes and allows easier location of fast moving objects. These are bespoke and provide important binocular eye relief for eyeglass wearers.
What Is Eye Relief In A Binocular?

This is what I should of known about months ago. I had changed my glasses three months prior to the trip as my sight had changed. At this point I should have got an understanding of what eye relief is.

Using normal binoculars with your glasses keep your eyes back too far from the lens. Looking through the lens the user will suffer with crescent vignetting. This is a sort of half-moon shadow at the edge of the field stop.

With binoculars that provide eye relief the eyecups are set back thus shortening the distance between your glasses and the lens. Typically the fixed distance between the eyepiece lens and your pupil should be about 18mm. So with the eyepiece set closer to the lens the overall distance is again optimal.

I found that some eye relief binoculars only offer 13mm and this is not enough. 

It took just 30 minutes of Google research. Two minutes and $400 to purchase.

Instead including travel and accommodation it cost me $1500 plus 17 days to fail at my one in a lifetime twitch.

So whether you are following your dreams in the UK the US or elsewhere in the world get your kit sorted and use the simple tackle that is available to us.

 

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