All new is well forgotten old...
I`d published
here link to the old soviet magazine Спортсмен-Подводник.
So, my father knew personally of main editor of this magazine. Yuri Nikolaevich, very good friend of my father, asked him to bring article to this magazine. And when my father was in Moscow, he brings this article, and it was published in 1967, issue #19 (page 91).
Both, my father and his friend had glasses around -4 till -6 ... And both was a speargun fishhunters. And those years was not any masks with correction lenses...
So - this article is dedicated to the manual of very simple technics for lenses installation in to the mask
In the beginning it used for single glass masks (oldstyle, oval), later they used it for double glasses masks.
My father`s favorite mask was Technisub Falco. And he use it with installed lenses.
So, with google translator helps and some manual correction, here is translation of this article
Yury Gubin
Installing glasses lenses in to the mask
Among fans of underwater sports there are a lot of people who wear glasses. The installation of glasses in the mask is associated with great inconvenience, it is much easier to attach the glass on the glass.
This is done simply. Untreated glasses of the required diopters are purchased, the edges of the glasses are ground manually on a flat metal plate with an abrasive powder moistened with water. It is necessary to grind until an opaque girdle with a width of 3-4 mm is formed. Then a thin layer of white picein (*) is applied to the glass bands with a warm soldering iron (this is a mixture of wax and rosin or parafin and rosin).
The sight glass is removed from the mask and wiped well.
On the outside, along the major axis of the glass oval, two points are applied with ink, which correspond to the distance between the pupils of the eyes minus one centimeter. Diopter glasses are glued at these points. The glass of the mask warms up over the stove to the melting point of picein. The diopter glass is mounted so that the optical center and the point were on the same line.
With a light pressure on the diopter glass, excess picein is removed from the girdle. The contact point is transparent.
The second diopter glass is similarly glued. Then the edges of the glasses with a slightly heated soldering iron are poured with picein. The sight glass is mounted in the mask so that the diopter glasses are inside it.
The advantages of this method are great. Firstly, all objects in the water are visible on a 1: 1 scale, and secondly, fogging is eliminated between the mask glass and the diopter glass.
(*) originally - picein - it was mix of rare components, or one of this components
Picein - Wikipedia, but late name Picein was used for Mendeleev`s putty (originally wax and rosin) or bitumen and rosin, later modified to mix of parafin and rosin.
Parafin you can take from the white canddle, rosin you can find in the Radioshack or music instrument store (it used for fiddle bow).
Parafine and rosin balance should be around 1:4 till 1:6.
When you like to use lense only for gauges reading - you can install just one, like here
or here:
or using useless GoPro mount, you can add glasses to the mask
some ideas and photos taken
here
