Newbie here and Im trying to shore up buying my 15 x 70 binocular filters before they are gone.
I had decided on glass filters, orange, and was talking to sales person (40 years a science teacher and a big bino user himself) who advised me to get the $19.00 US mylar foam ones because expensive ones, glass or mylar, won't add anything to my view. He said it's the same stuff the paper ones are made of. I am stunned. And confused. Why not paste those on the end of my binos, since they don't add anything to my view?
I would appreciate your thoughts.
I wish you had included a link so I was sure I understood the question, but....
I think your question actually has two independent components: The filter material, and the mount.
As far as quality of the filter material, any reputable filter will safely allow you to watch the partial phases leading to totality. During totality of course you don't use a filter at all. Then there are receding partial phases where you use the filter again.
However, there are many things to see on the photosphere, the Sun's visual surface, using white light filters not only during the eclipse. For those you will see more with better filter material. General consensus is that Baader AstroSolar Visual Film gives the best view. I know Thousand Oaks has their fans and their current product is Solarlite Polymer film. (Baader shows white, as the sun truly is. Solarlite tints the view orange, as some people prefer.) The black mylar and such give less resolution. Also glass filters are (often) not optically flat and can distort the image. (I don't buy glass is sturdier. The film is tough and doesn't crack. Both are subject to scratches. You just have to take a little care with either.) So I think it is worthwhile getting Baader film, but I enjoy watching the Sun in general.
The other issue is the filter mount. Cardboard can work well, if it is snugly fitted and carefully held on. It is clearly cheaper both in materials and in manufacturing. Usually they come with the safe, but less sharp film. If you are only using this once for the eclipse, go for cardboard & mylar (American Paper Optics, under many many labels, seems to be the biggest player in this market. Rainbow Symphony also make eclipse glasses and has a few cardboard front filters.)
But if you expect to be interested in more regular use, I think the nicer filter mounts would be worth it. They're sturdier, attach better, and in general use better film for better views. AstroZap, Baader themselves, and Kendrick Astro all make aluminum holders and use Baader AstroSolar film. If you're really set on an orange view, Thousand Oaks makes aluminum holders with their Solarlite film that should also work well.
Good luck, (and get your order in! Only 60 days )