Light Leakage and Light Return

[strmrdr]

funny but not very helpfull val :}

As for the beans id just mash em with a hammer then split em.

 

[Iiro]

Oh,

I meant white and black = antireflector !!

 

[Garry H (Cut Nut)]

Black is when the crown is a window both ways and the pavilion is a perfect mirror, but the light came from a black or relatively dark area above the diamond. the most common dark area is the observers head

R&T
You said lots of interesting things

But regarding the source of reflected red light - we have experimented with loads of sizes and shapes over 15 years. We used a hand held map reader with a flat top and a parrallel cylinder for the first 10 years.
I also developed an additional different colored cylinder i put under the original firescope to demonstrate to students in the GAA Diamond Technology Diploma course (Al Gilbertson claims to be the inventor of that idea, but I may have arrived there first).

None of these things effects the leakage. Leakage is light coming from below or behind the diamond. You should try this - line the inside of the ideal-scope with black - if you can see any white then it is leakage

 

[Iiro]

Yes Garry,

The black is not reflected light, eaven though the pavilion mains act like perfect mirrors. This is old knowlege.

In philosophy there is thesis, antithesis (respose or counter attack) and result may be synthesis(the two together, only the synthesis has bigger meaning than thesis or antithesis themselves). In diamonds it is the same, you need both to get brillancy?

 

[Garry H (Cut Nut)]

Yes Sib, it is old knowledge, but not everyone who should understand it does:

A quote from one of our friends:

"Black or dark gray = Light entering and exiting the diamond perpendicular or near perpendicular to the table. This is simply the reflection of the shadow of your eye as you look into the viewer. The eyepiece/lens is perfectly centered over the diamond, therefore the color that is directly perpendicular to the diamond is the shadow of your eye. IMPORTANT NOTE: The facets that function in this role are the facets that are functioning like mirrors that are being directly pointed in your face. Facets that function in this manner represent areas of the diamond that will reflect the most intense beams of light in the diamond and is primarily responsible for colored light return, scintillation and in a lesser manner white light return. The more broad the mirrors are, generally the more colored light return we'll get, the more tiny mirrors we have positioned towards our face the more scintillating the diamond will be. These areas of black or dark grey I'd like to refer to as hot spots.

anti-reflector does not = hot spot ?????
Hot spot = dead and dark area in a diamond unless you put your finger into an electric socket and turn on the power. then it will look very bright

 

[Iiro]

Heh,
Well, we have discussed about this with Rhino

Also, I think there are more people who think the same way as Rhino. And they are right, if we narrow the eyepiece i.e. make smaller angle for relection, the mains return to reflectors.
Only when the mains are at 45° the angle of reflection does not matter.

This is one reason why I wanted to introduce or suggest this term. It might help understad the role of a particular facet, in a particular circumtance.