paddle arrows & obstruction

[nomnomnom]

sorry if this has been answered before, but what is the relationship between arrows that look like paddles and obstruction (if there is any)? are all stones that have arrows that look like paddles necessarily stones w/ obstruction issues (and vice-versa)? does symmetry have anything to do w/ the paddle arrows -- or does excellent symmetry merely guarantee equally shaped paddles in a stone w/ detracting angles?

thanks!

 

[Karl_K]

yes the paddles are caused by obstruction however the choice of colors in the scopes can make it look worse than it is in real world viewing.
Most of the time it is the secondary light source for those facets that is obstruction vs green zone(ASET) in others.
In other words with no red zone light(ASET) diamonds without paddles will appear bright in those areas compared to one with paddles.
It can however be so bad that even with red zone lighting(ASET) that area looks darker.
So the ultimate answer is it depends.
If one wears black and has big hair it is more of an issue than when one has short hair and wears white.

 

[yssie]

Date: 6/25/2010 2:27:03 PM
Author:nomnomnom
sorry if this has been answered before, but what is the relationship between arrows that look like paddles and obstruction (if there is any)? are all stones that have arrows that look like paddles necessarily stones w/ obstruction issues (and vice-versa)? does symmetry have anything to do w/ the paddle arrows -- or does excellent symmetry merely guarantee equally shaped paddles in a stone w/ detracting angles?

thanks!

RB, yes?

Pic of how the IS works: http://www.pricescope.com/idealscope_indx.asp

So yes, the ''paddled'' area when viewing through the IS is ''obstructed'', as in, will not return light because those areas require direct light input (75-90deg from the plane of the diamond table) to return light to your eyes. that is the relationship.

There is a gradient - mild obstruction wouldn''t be a problem for most, severe obstruction makes the stone look dark from a suprising distance, if angled properly.

Excellent optical symmetry guarantees equally shaped paddles, as you put it - excellent physical symmetry just guarantees excellent symmetry at the facet meets

Garry''s video at the bottom of the page: http://diamondscope.pricescope.com/
Discussion on obstruction: http://www.pricescope.com/forum/

 

[Lovefaith]

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