ASET vs. Platinum AGS Computer Generated Image

[kdn2684]

I've compared the ASET image with the AGS image found in the Platinum AGS Report. As you can see, both the images mirror each other very closely. My questions would be, would it be enough just by looking at the AGS Image? What benefit would having an ASET image do when you have the AGS Image? I'd imagine the AGS Image is very helpful in selecting diamonds from diamonds not in house such as Whiteflash Virtual Inventory or Bluenile (that's IF you can find a diamond with the AGS Platinum Report)

 

[kdn2684]

I forgot to ask. Are the AGS Computer Generated Image ALWAYS this accurate compared to the ASET Image????

 

[stone-cold11]

There might be scanning error in the AGS ASET map.

 

[yssie]

I've compared the ASET image with the AGS image found in the Platinum AGS Report. As you can see, both the images mirror each other very closely. My questions would be, would it be enough just by looking at the AGS Image? What benefit would having an ASET image do when you have the AGS Image? I'd imagine the AGS Image is very helpful in selecting diamonds from diamonds not in house such as Whiteflash Virtual Inventory or Bluenile (that's IF you can find a diamond with the AGS Platinum Report)

Definitely - it's an extra level of reassurance.

The AGS simulation is of the same 90deg angle as a photo through an ASET desktop scope. The simulation is clearly well-programmed. I'm fundamentally an experimentalist though (working as a programmer, ironically enough) and I always want the actual photo as reassurance, knowing what I do about mechanical/scanning uncertainty, programming error, printing/printing to web error...


I think there are two questions here:
1. Does the AGS simulation closely represent the actual ASET photo at a given angle
2. Is the AGS simulation (or for that matter an actual ASET photo) enough information with which to get a good idea of real-world appearance and performance to your eyes

And I think the answer to (1) is "Yes, usually" and the answer to (2) is an emphatic NO.


Take these two simulations:


It's better than just having the averaged, rounded numbers on a report like GIA's - gives you some idea of optical symmetry. That said, what do they *actually* tell you about how the stone will look? How the stone will "perform" - what sort of light return patterns can you expect? Most importantly, which would you choose?

Okay, so Leftie: upper/lower girdle angle is too large in some areas, thanks to some optical asymmetry. Pav doesn't look overly steep, from table reflection, so we'll assume crown is on the high side - and the asymmetry exaggerates the slight areas of light escape through the pavilion.
Compared to Leftie, Righty looks a right wreck. All that *green*, and bits of grey everywhere, and hardly any *red* under the table, and...

And yet -
IS/ASET for Leftie:
IS/ASET for Righty:




On PS we're so used to seeing these striking arrows patterns, clear (if not very high) optical symmetry patterns... I know I don't often know what to make of ASETs of stones without such precise faceting, given the lack of obvious facet delineation in the ASET sim






And some princesses -






And absolutely none of this addresses the other half of the equation: we can talk about the minutiae of what exactly the diamond is doing with the light it takes in 'til the cows come home, but what your eyes see, and what your eyes *like* to see - those, all the pictures and scans in the world can't tell you about!

 

[yssie]

There is also the fact that neither AGS nor GIA considers the effects of body colour or inclusions when evaluating light return and assigning cut grade (incl AGS w/ the light performance simulation).

Negligible differences caused by inclusions in a reputably graded (AGS, GIA in the US) VS, most SIs, or body colour up to say J/K, but clearly a visibly creamy N/O/P Crafted by Infinity RB is going to return light visibly differently from a D/E/F of the same size with an identical AGS simulation map. In the lower clarity grades there's no way to judge from the report if for example clouds/wisps are going to visibly disrupt light return/brilliance, etc.


An AGS0 I2:




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Crafted by Infinity O:

Crafted by Infinity E:

 

[Rhino]

Great points Yssie and why I oftentimes like to do my presentation in reverse. Ie. show the clients a suite of diamonds, learn what it is their eyes enjoy most then show them the science behind their personal preference.

 

[Karl_K]

I have seen some large errors in the generated ASET images and do not trust them.

 

[John P]

I have seen some large errors in the generated ASET images

Ditto. In fact we found ourselves requesting corrected scans on a level that proved impractical in terms of back and forth, etc. Unless a scan is quite "off" we generally just accept it now, and educate our stores that the actual ASET photo we provide is normally the image of best accuracy.

Scan technology will continue to improve. Hopefully at a fast pace.