Eye relief - rule of thumb method? (1 Viewer)

The-Wanderer said:

Tm

Re: "This point is frustratingly not at the apex of the curvature. It's probably adding a few mm to my required ER on its own. Flat fronted glasses for me next time - ha ha."

At a well advertised high street franchise, you can buy single lens frames for £25.00. I presume that would be affordable as birding bins.

You might, depending on your age, get a free eye test too!

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A well advertised franchise took £400 off me 18 months ago for a new set of glasses when they should have sent me to Moorfields eye hospital. Never again.

I go to a trusted local optician now. The same one every time rather than someone just passing through.

I might look into getting some 'birdwatching' glasses though. Single vision would be fine or even just distance and mid. Flat fronted, maybe take the Bill Oddie route i.e. John Lennon style.

Will look into it.

Tah

Tm

I'm not impressed with my franchise either, but it goes with the territory!

I gave up on the franchises over ten years ago. The last straw was an incorrect prescription, wrongly centred lenses and getting charged a premium price for budget, low index lenses.

Switching to an independant did cost a bit more, but it immediately doubled my acuity, like switching from 8x to 16x. Infinitely more cost effective than switching from a £100 binocular to a £2000 one.

David

typo said:

I gave up on the franchises over ten years ago. The last straw was an incorrect prescription, wrongly centred lenses and getting charged a premium price for budget, low index lenses.

Switching to an independant did cost a bit more, but it immediately doubled my acuity, like switching from 8x to 16x. Infinitely more cost effective than switching from a £100 binocular to a £2000 one.

David

Click to expand...

Similar experience some years ago: same result switching to a local independent opticians. Worth every penny.

Lee

Pete,

Quote

We measure from the outmost/top edge of the eyepiece in its lowest position (twisted down or folded down) to the point at which the exit pupil diameter is measured to be at it's maximum/optimum e.g. 5.25mm for an 8x42 binocular.

Unquote

Was this measurement method always thus? I am contemplating buying an Opticron Discovery 8x32, which your website gives eye relief as 17 mm, to use as a highly portable camera. If this figure is real it will not likely suit me but if it is measured as you describe, it should be good.

How far is the ocular glass behind the plane of the collapsed eyecup rim?

Many thanks