ASET Interpretation Question

How important are the following characteristics in an ASET? I see them on some H+A/ACA diamonds, but not others.

1) A green "crown" that follows the star facets (in some diamonds, the entire star facet is red)
2) Pairs of blue triangles near the based of the shafts (not the ones near the arrowheads)

The picture below shows both these phenomena. Does this indicate particular quality or symmetry?

It's hard to get a stone so perfectly perpendicular to the scope and camera that every minute characteristic comes out perfectly symmetric, not to worry

So to rephrase you answer - it depends on the skill of the photographer and the placement of the diamond, and not all characteristics of the stone are fully reflected in the image? Which is why we place some trust in the reputation of certain firms/individuals to pick good stones cut to their spec, I suppose. Ok...I just didn''t know how neurotic to get about these things.

I get it. I'm a bit of a hearts fiend, and am likely to recommend retaking a pic that most would consider viable.

But even the best and most repeatable series of pictures cannot fully capture all the characteristics and personalities of a diamond.

hee hee... Yssie is indeed a hearts fiend

10rock I think one issue that you are having in learning about ASETs for RBs is that the only companies that automatically supply ASET images are those that sell "super ideal" H&As on PS. This means that all the ASETs of RBs that we tend to see around here are GREAT looking. If you say some crummy ones it would be clearer what aspects of the ASET are artifacts of the photography and which aspects are important for understanding optics. Same with IS images, almost all of the ones we see are really great or almost perfect anyways because we weed out the poor ones from numbers before IS images are even taken. When you see a dud, it is pretty darn obvious.

Dreamer - that was sort of my starting assumption, that ASETS for superideals would be broadly similar. But as I started to scrutinize these - and I realize I am perhaps being super picky here, but perhaps not - I don''t see the same ASET attributes across all superideals. For example, here''s an ASET of a BGD H+A. But it doesn''t have either the crown or the hot spots by the shaft. Is this the stone, or the camera, or "human error"?

10rock-


Check out what the ASET scope looks like:
www.ideal-scope.com

It is a lens viewer with a cone of coloured bands. When a stone is backlit, the white light reflects off the three colours of the cone onto the table and crown of the diamond, reflected and refracted within the diamond, and outputted to the lens. The colours you see indicate the 'type' of light output in that area of the stone - direct (red, 45-75deg), indirect (green, 0-45deg), none due to head obstruction (blue, 75-90deg), and none due to leakage (white or black).



There are several factors influencing the colour any area of the diamond will show in a picture from a handheld ASET scope:
1. The angle of the diamond relative to the scope
table should be perpendicular, ASET image is only good for whatever angle it shows at that instant in time.
2. The height at which the scope is held above the stone
if the bottom of the cone is sitting on the plane of the stone (directly on the backlight) the coloured bands will throw coloured light onto the diamond at certain angles (listed above). If the bottom of the scope is a few mm above the plane of the stone, the coloured bands will throw coloured light onto the diamond at a slightly shifted range of angles - now "direct" light might mean 50-80deg, indirect 5-50deg... This is setup specific.
3. Focus
unfocussed picture will show blurring between the colours rather than crisp definition. This is especially problematic if using a black background, as blue and black can merge. The ASET viewer lens must both magnify and focus on the stone, and then some cameras might have difficulty focusing through the magnification of that lens.
4. Post-photography manipulations
does an individual or vendor sharpen the picture? Dial up the contrast? Increase saturation of the colours for clarity?
5. Is the picture sent to you or posted online of sufficient quality to be an accurate representation of the original image? Did changing the file formats affect the colours?

Very helpful in providing some perspective! I think the next step is to call and discuss individual stones, rather than leaning too heavily on the images. Thanks for all the help, Yssie!

Date: 6/23/2010 7:32:40 PM
Author: 10rock
Very helpful in providing some perspective! I think the next step is to call and discuss individual stones, rather than leaning too heavily on the images. Thanks for all the help, Yssie!

Click to expand...

Always the best thing to do Glad I could help!