Aset image help

[treasurehunter]

What is the affect by the culet ?

 

[treasurehunter]

Is it better to have red in the culet area or is green ok ?

 

[04diamond<3]

Is it better to have red in the culet area or is green ok ?

Red and green are ok, red however indicates perfection, but I wouldn't throw it out because it's green. Do you have a link to the stone? The aset looks pretty good!

 

[WinkHPD]

What is the affect by the culet ?

Whether or not the culet shows red or green depends on the exact pavilion angle. In this stone some of the lower pavilion mains are apparently above that angle and others above the angle.

Peter Yantzer, the Executive Director of AGSL says that whether the center is red or green is of negligible importance as it is nearly impossible to see. Remember that the ASET is an enlarged view of more than an inch on our monitor and is MUCH larger than the diamond that we are looking at with our eyes.

Wink

 

[c-k]

Is it better to have red in the culet area or is green ok ?

Red and green are ok, red however indicates perfection, but I wouldn't throw it out because it's green. Do you have a link to the stone? The aset looks pretty good!

Perfection is not determined by the culet in the ASET being red or green or a combo of both.....

I believe it is somewhere at 40.70- 40.75 it changes from green to red ....as the 8 pavilion angles will vary, you could have a AGSL stone where the lab report w/ASET being green and the angle spec is 40.8

 

[John P]

c-k is wise.

This is a table-reflection artifact. Table reflection is not true light return, it's literally a reflection (in the center-table) of what the pavilion "sees" above... When the pavilion angle is less than 40.768 degrees the table reflection area shows green. When increased to above 40.768 it shows red.

Outside of the structured light environment it's negligible. I have been told, off-the-record, by AGSL staff that choosing 46-75 degrees (rather than 45-75) may have been easier for the consuming public to understand, since all "robust" pavilion angled stones (circa 40.6-41.0) would have the same appearance.

Summary: It's not an issue. Merely an artifact of internal reflection.

(Image Copyright, AGS 2005 - Used with permission)

 

[John P]

What is the affect by the culet ?

You may already know, but what you have posted is not an actual image. It's a computer simulation, generated by numbers either input manually - or a 3D scan of the diamond.

FYI.

 

[c-k]

What is the affect by the culet ?

You may already know, but what you have posted is not an actual image. It's a computer simulation, generated by numbers either input manually - or a 3D scan of the diamond.

FYI.

John a question of you if I may...ASET generated by computer vs an actual ASET on the same round diamond, it appears they are very close, would this be to say a computer generated ASET is an accurate image?

 

[Karl_K]

John a question of you if I may...ASET generated by computer vs an actual ASET on the same round diamond, it appears they are very close, would this be to say a computer generated ASET is an accurate image?

Under perfect conditions and the right scanner/calibration/process/cuts generated images can be pretty accurate but in the real world they are far less so and should not be relied upon for a sale decision.

 

[John P]

John a question of you if I may...ASET generated by computer vs an actual ASET on the same round diamond, it appears they are very close, would this be to say a computer generated ASET is an accurate image?

They're largely reliable on AGSL reports. In Vegas they calibrate their equipment daily, use the latest imaging hardware and software updates and clean the stage between scans. Even so, they're not infallible. We occasionally must contact the lab to reject a scan that does not match the diamond we submitted. In every case they have quickly corrected the issue, which is great. But it doesn't negate the fundamental problem.

Technically, Sarin's given error for the DiaMension scanner remains ± 20 microns (± 0.02 mm) linear and ± 0.2 degrees angular. While I think this is exaggerated - based on experience with our scanners - I do know that it's possible to have that degree of error (and more) if the equipment is not up-to-date, calibrated daily and kept immaculately clean between scans.

Bottom line: Those who make actual ASET photos in a controlled, standardized (sic) environment produce more reliable images than current computer simulations. What does that mean? ...If I was splitting hairs, unable to see the diamond IRL, I'd prefer to see an actual image over a computer sim every time.

 

[denverappraiser]

There’s a subtle problem that happens here. The dividing line between the red and the green is at a 45 degree angle from the girdle plane. Computers are good at getting this sort of thing perfect. Humans are less so. There are several ways people setup for the photographs of an ASET but the always involve placing a reflector cone over the top of the stone with the opening of the cone at the same level as the girdle plane. Even if you’re careful it’s easy to miss this alignment by a few millimeters and if you’re not attentive to it, it’s almost always off by a tiny bit. Given that we’re talking about variations of 1/10 of a degree to flip it from red to green in the middle, these alignment variations are actually relevant.

Similarly, the computer models are based on a scan with an optical scanner. The manufacturers stated margin of error on these scanners, when properly calibrated, is 0.2°. That may seem tiny but, as with the above, with what we’re talking about it’s important.

 

[c-k]

Thanks guys great information....

 

[c-k]

As the actual ASET imagine could show inclusions, where the AGSL computer generated would not, light performance could be hindered in real life.

Maybe all of this stuff is more than the human eye can see, I know having a stone that has Ideal cut is important, but how much of all this can the human eye really see. Where or should I say what numbers make for perfection. I can't tell a G color from a I color in a set diamond, I can hardly ever see inclusions in a SI2 stone and in a VS1 with a 10x it takes me forever to find one if I am lucky, I can see what I consider a well cut diamond most of the time...but to what degree do I see an Ideal from a Super Ideal, I don't think I could.....huh, thinking out loud