Newbie Question on Hearts & Arrows Scope - symmetry

[poosplat]

Hi all,

Forgive me if this question sounds rudimentary, i'm new to diamonds.
i was just wondering that under the hearts & arrows scope, some of the "mini triangles" lack symmetry (as in the attached picture)
This is also true in some of the actual diamond photos,

while the same diamond on the ASET and IdealScope, the triangles look fine, why is this?

Thanks Guys!

 

[delight]

I think that the pictures taken with this bluescope is not done accurately. The ASET and Idealscope should reflect a more accurate representation.

 

[poosplat]

anyone can fill me in on the difference between an ideal scope and the hearts and arrows scope?

 

[poosplat]

I found out a little more... According to this site, there are poorly formed h&a with good ideal scope images.

http://www.ideal-scope.com/3.manuf_hearts_and_arrows.asp


Question, which scope is a better reference for symmetry?

 

[John P]

anyone can fill me in on the difference between an ideal scope and the hearts and arrows scope?

Poosplat huh?

IDEAL-SCOPE: The ideal-scope is designed to show light-return and light-leakage. Fundamentally this is far more important than the purpose of the H&A viewer. In fact, robust light-return as seen in ideal-scope or ASET should be a prerequisite, with H&A 3D precision considered "icing on the cake" which contributes to the technical notes two paragraphs below. What you see as black in the ideal-scope is obstruction, or light normally blocked by the viewer's head, directly above and occupying around 30 degrees of high hemisphere. What you see as red in the ideal-scope is light returned from the horizon up to around 75 degrees vertical - the "usual" area from which a diamond gathers light. What you see as white in the ideal-scope is leakage, or places where the facets are acting as windows rather than mirrors.

QUALITY: Since the ideal-scope is standardized most setups can be reliably interpreted if back-lighting is appropriately used. Ideally - pun intended - there will be an abundance of red light return, with crisp, symmetrically distributed black (similar to the H&A viewer arrows in a round brilliant) and minimal white - except for an acceptable level of small, triangular "contrast leakage" spots symmetrically distributed along the girdle and at facet meet-points (again, in a round brilliant).


H&A VIEWER: The H&A viewer is an instrument designed to show 3D cutting precision space or, in layman's terms, how well the diamond's internal mirrors align with one other. What you see as white in a H&A viewer is light from above. What you see as blue (or red or another color) is coming through filament paper coating the side of the viewer. The sole purpose of the H&A viewer is to demonstrate the degree of optical symmetry, or 3D precision, of the cutting. In the crown view the pavilion mains are key. If they are cut precisely and directly opposite each other their facet reflections will overlap to create eight "arrows." In the pavilion it takes 5-6 facet reflections overlapping to create "hearts." Technically, a top level of 3D cut precision, when paired with light return as a fundamental (see above) creates a crisper on-off quality to the diamond's scintillation and larger virtual facets - which contribute to more visible dispersion and scintillation events able to be seen from greater distances.

QUALITY: The viewer, the darkness of the filament paper, the orientation of the diamond and the size of the image are all variable. A viewer that uses magnifying glass and dark paper where a tiny .jpg image is produced will minimize any aberrations, whereas a viewer with the glass removed (so the camera lens is the magnifier) lighter paper is employed and a large .jpg is produced shows minutia on a far greater scale. The same diamond looks quite different in different setups. Since there is no standardization it's difficult to make apples to apples comparisons from different sources. For most consumers it's not much of an issue, but for me live viewing with an appropriate viewer is necessary to make judgments at the most detailed levels. #mecutnerd.

 

[John P]

i was just wondering that under the hearts & arrows scope, some of the "mini triangles" lack symmetry (as in the attached picture) This is also true in some of the actual diamond photos, while the same diamond on the ASET and IdealScope, the triangles look fine, why is this?

Evenness of lighting, overlap or seam in filament paper, centering of the diamond in the viewer-cylinder may all cause some of the secondary/tertiary reflections to be non-uniform. In some cases internal characteristics such as feathers, crystals or knots may disrupt and/or reflect in the pattern. For any crown view (mag, arrows, ideal-scope, ASET) uniformity will only be as good as the alignment of the diamond's table to be precisely parallel with the camera lens. Even then, evenness of lighting and uniformity of surrounding environment, as before, can influence the result.

Diamond photography is pretty difficult. These are extremely tiny objects, magnified by tens and tens of powers in tricky environments.

The image you posted is small but, for what it's worth, the areas you circled are not a concern to me if good pattern uniformity is what you're seeking; particularly considering the shape.

 

[poosplat]

Thanks John for your answers!! been a great help!