Advice on this diamond before I lock it in

[John P]

I mentioned up top that I thought the ASET listed on teh report was a computer generation. It has that flat look I see on all the AGS Performance reports that I don't see in "real life" ASETs. That's the best I can give you. Maybe someone else has better info.

Correct. The ASET and H&A views on that document were generated in software using a 3D scan of the diamond.

 

[bunnycat]

I mentioned up top that I thought the ASET listed on teh report was a computer generation. It has that flat look I see on all the AGS Performance reports that I don't see in "real life" ASETs. That's the best I can give you. Maybe someone else has better info.

Correct. The ASET and H&A views on that document were generated in software using a 3D scan of the diamond.

That is so cool John (the 3 d scanning thing). Is there a thread somewhere that discusses the differences you might see in a computer generated versus actual ASET? Or maybe does it have to do with the "rounding" factor y'all discussed upthread being used in a computer generated image versus an actual ASET taken of the stone? I've not put tons of thought in to the whys, only this "is" and know only that I usually see the blue around the middle in the computer generation and then when I compare to the real life ASET, I don't see that contrast. Thanks!

 

[John P]

That is so cool John (the 3 d scanning thing). Is there a thread somewhere that discusses the differences you might see in a computer generated versus actual ASET? Or maybe does it have to do with the "rounding" factor y'all discussed upthread being used in a computer generated image versus an actual ASET taken of the stone?

Indeed it is cool I don't recall a specific thread about this. I do have a bazillion examples; actual images vs scanned.

I should say that making actual photos is extremely difficult, especially as it relates to keeping the stage, camera-lens and diamond-itself 100% on-axis with each other. Even a small degree of tilt (lens, diamond or stage) skews the resulting image. Considering the time, expense and payroll cost of producing actual photos it's logical that more companies are taking inexpensive scans and using software to simulate these images.

I think that's completely fine - as long as you consider them in context. What many don't realize is that reported error for the best 3D diamond scanners is ± 0.1 degree angular and .01% linear. More common scanners have double that error. Thus...

* If you simply want mm spread measurements to design the setting any decent scan will serve.
* If you want table% and 2D averages of CA, PA, etc. to see what a proportions-based cut grade is any decent scan will serve.
* If you want to run the 3D scan through software and establish a performance-based cut grade a good scan will serve.
* But at present, NO scan can precisely replicate how the actual diamond appears in ASET and optical precision viewers.

For 99% of the diamond-producing world a good scan is satisfactory.
For those of us committed to the highest level of optical precision it's a constant frustration. GIGO.

As an example; AGSL has some of the best scan tech in the world. It is certainly capable of placing diamonds into their different cut grades (0,1,2 etc). But they also use these scans to produce computer-generated ASET imprints on their grading reports, and we must regularly instruct them to re-scan our diamonds in order to correct imprints where clear error exists.

I've not put tons of thought in to the whys, only this "is" and know only that I usually see the blue around the middle in the computer generation and then when I compare to the real life ASET, I don't see that contrast. Thanks!

That is a table-reflection dynamic that tends to be exaggerated in some scans. On AGS reports it's related to baseline angular choices such as the one described in this thread, where you see central-green (or not) depending on interesting minutiae.

[URL='https://www.pricescope.com/community/threads/ags-aset-40-768-pavilion-on-the-ledge.29977/']https://www.pricescope.com/community/threads/ags-aset-40-768-pavilion-on-the-ledge.29977/[/URL]

Ok. Really? That thread occurred in 2005? Holy smokes I'm getting old.

 

[bunnycat]

That is so cool John (the 3 d scanning thing). Is there a thread somewhere that discusses the differences you might see in a computer generated versus actual ASET? Or maybe does it have to do with the "rounding" factor y'all discussed upthread being used in a computer generated image versus an actual ASET taken of the stone?

Indeed it is cool I don't recall a specific thread about this. I do have a bazillion examples; actual images vs scanned.

I should say that making actual photos is extremely difficult, especially as it relates to keeping the stage, camera-lens and diamond-itself 100% on-axis with each other. Even a small degree of tilt (lens, diamond or stage) skews the resulting image. Considering the time, expense and payroll cost of producing actual photos it's logical that more companies are taking inexpensive scans and using software to simulate these images.

I think that's completely fine - as long as you consider them in context. What many don't realize is that reported error for the best 3D diamond scanners is ± 0.1 degree angular and .01% linear. More common scanners have double that error. Thus...

* If you simply want mm spread measurements to design the setting any decent scan will serve.
* If you want table% and 2D averages of CA, PA, etc. to see what a proportions-based cut grade is any decent scan will serve.
* If you want to run the 3D scan through software and establish a performance-based cut grade a good scan will serve.
* But at present, NO scan can precisely replicate how the actual diamond appears in ASET and optical precision viewers.

For 99% of the diamond-producing world a good scan is satisfactory.
For those of us committed to the highest level of optical precision it's a constant frustration. GIGO.

As an example; AGSL has some of the best scan tech in the world. It is certainly capable of placing diamonds into their different cut grades (0,1,2 etc). But they also use these scans to produce computer-generated ASET imprints on their grading reports, and we must regularly instruct them to re-scan our diamonds in order to correct imprints where clear error exists.

I've not put tons of thought in to the whys, only this "is" and know only that I usually see the blue around the middle in the computer generation and then when I compare to the real life ASET, I don't see that contrast. Thanks!

That is a table-reflection dynamic that tends to be exaggerated in some scans. On AGS reports it's related to baseline angular choices such as the one described in this thread, where you see central-green (or not) depending on interesting minutiae.

[URL='https://www.pricescope.com/community/threads/ags-aset-40-768-pavilion-on-the-ledge.29977/']https://www.pricescope.com/community/threads/ags-aset-40-768-pavilion-on-the-ledge.29977/[/URL]

Ok. Really? That thread occurred in 2005? Holy smokes I'm getting old. quote]

Wow- fabulous info! Thank you kindly for taking time to answer. I totally understand the frustration, while also being one who is accepting a "good scan" as good enough. Now I will just keep the differences and reasons in mind. And, lol, I'm gonna have to click and read through that old thread!

 

[WinkHPD]

Ok. Really? That thread occurred in 2005? Holy smokes I'm getting old.

Great thread from the past. That was enjoyable to revisit. And you’re only as old as you feel, my friend.

 

[rbpro]

Correct. The ASET and H&A views on that document were generated in software using a 3D scan of the diamond.

Thanks for confirming.

My concern - if that was the real ASET image - was that it would be similar to this:


And diamond potentially looking dark in the centre:



Left image shows stones under diffused lighting
Right image shows stones but with an obstruction between the light and the stone, with the dark areas being likely to show blue in an ASET.

Photo credit: User 'davidelevi' (Not sure if I was allowed to post links to other forums).

I never viewed my loose diamond under fluorescent lighting so I was unable to ascertain if mine has this issue.

That said, my diamond was less bright and had less fire towards its centre: is this common?

 

[rbpro]

Any chance your jeweler has a Sarin or Ogi scanner? If so, upload the .SRN or .STL here.

Will find out. There's a change they haven't heard of these so I'll ask them if they have any scanning equipment too.

 

[bunnycat]

Correct. The ASET and H&A views on that document were generated in software using a 3D scan of the diamond.

Thanks for confirming.

My concern - if that was the real ASET image - was that it would be similar to this:


And diamond potentially looking dark in the centre:



Left image shows stones under diffused lighting
Right image shows stones but with an obstruction between the light and the stone, with the dark areas being likely to show blue in an ASET.

Photo credit: User 'davidelevi' (Not sure if I was allowed to post links to other forums).

I never viewed my loose diamond under fluorescent lighting so I was unable to ascertain if mine has this issue.

That said, my diamond was less bright and had less fire towards its centre: is this common?

I'm a little confused. Are the ASET pictures you posted of the diamond pictures beneath it? Or just diamond images you worry that the left ASET picture might look like in person but aren't actually of the stone pictures below? Some of those look like they have tables you could skate on....What does an ASET of a diamond with a 65% table look like?

I guess I am imagining an ASET of the smaller stones looking more like this and not like the left ASET picture you showed (with the extra blue contrast)...(Maybe John will see this and come lay down the law! )





Here's another image i googled that shows a diamond that looks face up a little more like the two smaller stones shown, and it's actual ASET:



and here's an old essay from Garry H that may also yield some amswers for you and has aset imagery:

http://www.pricescope.com/journal/gia_excellent_cut_grade_case_study

 

[rbpro]

I'm a little confused. Are the ASET pictures you posted of the diamond pictures beneath it? Or just diamond images you worry that the left ASET picture might look like in person but aren't actually of the stone pictures below?

The two diagrams are unrelated: not of the same diamond/s. Yes my concern was that it'll look dark in the centre.

 

[bunnycat]

I'm a little confused. Are the ASET pictures you posted of the diamond pictures beneath it? Or just diamond images you worry that the left ASET picture might look like in person but aren't actually of the stone pictures below?

The two diagrams are unrelated: not of the same diamond/s. Yes my concern was that it'll look dark in the centre.

Here is a discussion on actual versus computer generated ASET. It's short, and I do think it addresses pretty well your question of the blue in the generated ASET and how that relates to actual ASET. In particular, your question relates to the first set of images, third stone down.

[URL='https://www.pricescope.com/community/threads/aset-vs-platinum-ags-computer-generated-image.164393/']https://www.pricescope.com/community/threads/aset-vs-platinum-ags-computer-generated-image.164393/[/URL]

I guess what I was wanting to ultimately convey is in looking at the smaller stones you posted in the stone trio versus the ASET image pair, IMO there's just no way in your pictures above that the two smaller stones would have the ASET like the left side ASET. They would look more like the ASET I found.


Also, I've been digging these videos lately...and visuals can be more fun than reading long articles sometimes but make a similar point....

https://www.youtube.com/watch?v=r5GuscVlPv4
https://www.youtube.com/watch?v=UByUngPLp-M

Good Old Gold also has lots of education videos. They are longer, but go in depth in information.