UV protection for the person using a binocular (1 Viewer)

[Ted Y.]

A few binoculars have UV coating and I like to believe it is for the protection of the person using the binocular.
Most binoculars don't have a filter thread in front of the objectives, but Fujinon HC has 46mm threads.

For testing, I added one single photo UV filter who locks ultraviolet light waves below 370 nanometers. It is a slim multi-coated filter but is not the “best of the best”. No vignetting, no optical aberrations to be mentioned, except the green color is changed to a browner color. Inacceptable, at least for birding.
I used a Steiner Safari Ultrasharp UV coated, and the green was green, no surprise.

I will order a much better (more $$$) UV filter and try again.

The questions are: Must have UV protection? Is nice to have UV protection?

 

[henry link]

The 100-125 mm of glass thickness in a typical binocular is a UV filter. You don't need another one. I picked the transmission graph of a Zeiss 8x42 SF below at random just because it was on the first page of the Allbinos review site. Notice that the transmission curve begins to take a nose dive at 410-420 nm. The probable curve when extended into the UV would likely hit zero transmission around 350-370 nm.

 

[Pinewood]

Hello,

You surely need UV protection in sunlight. Sunglasses are the answer, in the summer, on the beach, over water, above the tree line and in a desert, but you can remove them when viewing through binoculars with poor eye relief.

Stay safe,
Arthur

 

[Ted Y.]

See this thread.

 

[CharleyBird]

A recent fascinating BBC Radio 4 programme was mainly about choosing efficient sunglasses, but I remember the brief medical advice to wear them as much as possible, i.e. in winter in low sun as well as during intense summer sun, as they help prevent eyes aging.

BBC Radio 4 - Sliced Bread - Is it worth paying for expensive sunglasses?

Eight things to consider before splashing out on new shades

www.bbc.co.uk