When are IS, ASET, and/or reflector technologies needed or not needed for internet purchasing…(?)

[Regular Guy]

This is an old question with new prompts. Today, it is:

- the question from jconnor97
- - recently, it is raised by Karl…and if I read him correctly, challenged by Michael Cowing in this recent “storm” about the differential between gold and platinum ratings with AGS, and
- longer ago, I raised it here…

Essentially, for a responsible shopper who only wants the best, don’t you know, but doesn’t want to overpay for it (sticking perhaps with platinum, but even then?...)…

Do they need to have evidence with reflector technologies, or not? If not, when…and if so…when.

I will stipulate that there are likely border calls, where you can plot crown & pavilion angles on the HCA, and see you’re close to a border, and wonder if measurement error of some broad sort won’t make actuals a problem. But…when you’re somewhat not near a border, maybe you just don’t need the extra protection. And therefore…for example, Blue Nile is actually OK…reliably?

I think Garry stipulates issues like digging and painting are problems. I asked him maybe 6 weeks ago, when a user asked why…given a certain crown & pavilion combo, a cutter would decide to add either painting or digging…but either he didn’t understand the question, or I didn’t understand the answer.

Really the question I have, that I think I have asked before, and that I know jconnor97 today wants to know…is…is there any frequency to speak of, really, when an HCA score for a GIA excellent where the cross hairs in the AGS & GIA primo ranges…that the IS provided would not also be as good or better than might be expected? Has anyone actually ever seen a loser IS, when strong proportion data is in hand. What data does anyone actually have on this? And…if you don’t have good data…why continue to insist on the IS. Or…to say it another way…why even stipulate the Platinum is more likely to be better? Yes, it is the reasonable expectation…but has anyone really looked for and found confirming or disconfirming examples?

 

[Regular Guy]

Repeating again...

Date: 11/6/2008 10:46:25 AM
Author:Regular Guy

Has anyone actually ever seen a loser IS, when strong proportion data is in hand?

Thanks,

 

[strmrdr]

Date: 11/6/2008 5:49:22 PM
Author: Regular Guy
Repeating again...

Date: 11/6/2008 10:46:25 AM

Author:Regular Guy


Has anyone actually ever seen a loser IS, when strong proportion data is in hand?

Thanks,

yes many times!!!

 

[strmrdr]

Round ags pgs0/dqd will get you close to the top and if there is no other information available I would still consider one but much prefer to have the scope images.

No other system will I give that much trust to including gold ideal as they are 2d proportion based and can only be used for rejection!

No fancy cut of any kind can be purchased without images.

 

[strmrdr]

If someone wants to learn absolutely nothing about diamonds and doesn't want a lot of help but wants a well cut RB I tell them AGS0 DQD H-vs2 and be happy.
With a little homework a much wider world opens to them.

 

[Rhino]

Absolutely Ira.

As I answer this bear in mind that while I utilize reflector based technologies in my exams I do not point to them as an end/all be all solution. I''ve seen reflector images taken before that suggest no leakage when there is blatant leakage and even accurately taken reflector images do not always genuinely communicate head/body shadow. As you also know painted diamonds as well as shallow angled diaimonds look great in reflectors yet will not make GIA Ex and in cases AGS Plat ideal either. This data I was about to post in a 34/41 thread I saw yesterday but the data seems appropriate here as well.

Having said that take the following 2 diamonds we had here not long ago...

We''ll start with Sarin''s. Take a look at the average angles and table sizes of the 2 diamonds.

 

[Rhino]

Sarin on Diamond #2

Both diamonds very close to same weight and their crown pavilion angles are virtually identical. If you were looking at GIA Reports on the 2 diamonds you would think they were virtually identical in every respect.

 

[Rhino]

I didn''t realize how late it was. If I can''t finish posting the data I want to I''ll pick it up tomorrow but will post some mkore before I cut out here tonight. Here are the Arrows images as generated via our scanner. I can''t recall if these were generated via Helium or Sarin but they accurately reflect the actual imagery we take via photography.

 

[Rhino]

Here is the pavilion side ... same viewer.

Clearly there is a craftsmanship issue that is not reflected in current GIA/AGS Reports.

The Optical Symmetry on one diamond is right on (Hearts & Arrows) while the other is chaotic (wonky).

 

[Rhino]

DiamXray shows an obvious difference. The pavilion facets on one show superior reflections off the pavilion while the other demonstrates some notable leakage under the table.

 

[Rhino]

Isee2 comparison... the order is inversed on this report. The better diamond is on the right and scores a 9.8. Note the hit in "symmetry" via the bars too. Another reason I like the Isee2 technology.

 

[Rhino]

Gotta cut out. One more interesting piece of data to post tomorrow.

This comparison answers quite a few questions regarding ...

a. The importance of Optical Symmetry.
b. What can impact the 41.0 pavilion angle positively or negatively.

Peace till then.

 

[strmrdr]

Thanks Jon!
Can you run the AGS PGS report for these 2 diamonds please.

 

[Paul-Antwerp]

Hi Ira,

It depends upon comfort level and upon what you are trying to study.

If one wants to talk in general without going into too much detail, one can limit one''s observations to average angles only.

If one wants to buy a diamond, and one is comfortable with a cut at least slightly above average, one can also limit one''s observations to average angles only.

However, if one wants to buy a diamond, and one wants to aim for the very best cut-quality, reflector technologies are part of the extra necessary information. One simply cannot assume that the average numbers accurately represent the diamond.

Live long,

 

[Serg]

If we speak about RBC,
Now you need use both : Images in structure lights and proportions set( better 3d model) .
If you use only Structure light images you can easy let pass very steep pavilion, shallow crown( Table view is nice, but tilt shows problem)

 

[Rhino]

Amen to that Paul and Serg. Here are the photographs as compared to the models then I''ll load PGS results on the two.

 

[Rhino]

PGS on the diamond with precise optical symmetry.

 

[Rhino]

PGS on the other. AGS 3 in light performance.

Interestingly on the proportion diagram it lists max and not average pavilion angle. In any case ... the thoughts that go through my mind as I saw this comparison is ...

1. Justification for knocking average 41.0 pavilion angles *especially* if they represent commonly cut goods (and in this case even GIA Ex).
2. At the same time dead wrong to make sweeping statements that mislead consumers into believing that all 41.0 pavilion angles are bad. I say this because clients of ours were falsely told that a diamond of ours was bad or questionable because of a 41.0 pavilion angle when all the hard evidence suggested the exact opposite (like the diamond with precise optical symmetry used in this example).
3. Optical Symmetry can make or break a diamond or a deal (at least between me and suppliers).
4. Optical Symmetry in this instance also made all the difference not only in light performance but a ray trace grade as assigned by AGS PGS.
5. Proportion based cut grading systems will never tell the full story. (Though I understand why labs use them). Nothing replaces the live analysis.
6. Variances, deviations in both slope and azimuth angles, which affect optical symmetry is also important information to have, at least to us geeks who are looking for the best.

Peace,

 

[strmrdr]

Thanks Jon...
This is why AGS gold is a very bad thing it would give both those diamonds the same grade.
GIA would also.
HCA would also.

Proportion based systems can't be used for selection this is a perfect example of that!!!

 

[Serg]

Date: 11/7/2008 11:17:09 AM
Author: Rhino
PGS on the other. AGS 3 in light performance.

Interestingly on the proportion diagram it lists max and not average pavilion angle. In any case ... the thoughts that go through my mind as I saw this comparison is ...

1. Justification for knocking average 41.0 pavilion angles *especially* if they represent commonly cut goods (and in this case even GIA Ex).
2. At the same time dead wrong to make sweeping statements that mislead consumers into believing that all 41.0 pavilion angles are bad. I say this because clients of ours were falsely told that a diamond of ours was bad or questionable because of a 41.0 pavilion angle when all the hard evidence suggested the exact opposite (like the diamond with precise optical symmetry used in this example).
3. Optical Symmetry can make or break a diamond or a deal (at least between me and suppliers).
4. Optical Symmetry in this instance also made all the difference not only in light performance but a ray trace grade as assigned by AGS PGS.
5. Proportion based cut grading systems will never tell the full story. (Though I understand why labs use them). Nothing replaces the live analysis.
6. Variances, deviations in both slope and azimuth angles, which affect optical symmetry is also important information to have, at least to us geeks who are looking for the best.

Peace,

Rhino,


Does this stone have Pavilion digit-out?

If yes, Optical Symmetry is irrelevant explanation for downgrade

Diamond with Digit-out or painting could have High level symmetry .

P/s for Karl. This is not example what PGS sensitive to symmetry. ( Most probably digit-out is reason)

 

[Regular Guy]

Thanks, gentlemen.

Am I following the ball on this?

Three questions, to at least Jon:

1)

Is the one that was on the right where there was a picture here...

Date: 11/6/2008 9:19:10 PM
Author: Rhino
DiamXray shows an obvious difference. The pavilion facets on one show superior reflections off the pavilion while the other demonstrates some notable leakage under the table.

...the one that showed leakage (but scored better using the ISEE2 technology)...that was the one that uniquely gets 0 as in AGS platinum...and not the other one without the leakage, which gets a 3?

I''ll say that again...

was your result:

per reflector technology

leakage = 0 from PGS (= Platinum zero)

non-leakage = 3 from PGS ( and an AGS Platinum 3)

-----------------

2) If I''m correct above (and I may not be), which one did you prefer, anyway.

3) Why?



-

 

[strmrdr]

Date: 11/7/2008 12:52:22 PM
Author: Regular Guy
Thanks, gentlemen.


Am I following the ball on this?


Three questions, to at least Jon:


1)



Is the one that was on the right where there was a picture here...

Date: 11/6/2008 9:19:10 PM

Author: Rhino

DiamXray shows an obvious difference. The pavilion facets on one show superior reflections off the pavilion while the other demonstrates some notable leakage under the table.

...the one that showed leakage (but scored better using the ISEE2 technology)...that was the one that uniquely gets 0 as in AGS platinum...and not the other one without the leakage, which gets a 3?


I''ll say that again...



was your result:


per reflector technology


leakage = 0 from PGS (= Platinum zero)


non-leakage = 3 from PGS ( and an AGS Platinum 3)


-----------------


2) If I''m correct above (and I may not be), which one did you prefer, anyway.


3) Why?




-

The leaky one got the PGS 3 and the lower isee2 score, you can tell by the pic and ASET image.

 

[strmrdr]

Jon it has been suggested that the difference might not be eye visible since you saw both please comment on that.

 

[Serg]

Date: 11/7/2008 4:48:37 PM
Author: strmrdr
Jon it has been suggested that the difference might not be eye visible since you saw both please comment on that.

 

[jasontb]

I would expect that it would be quite easy to see the difference between an AGS0 and an AGS3 (as somebody who doesn''t know too much about these grading systems, especially regarding where they break down and lead to inconsistencies).

Am I wrong to necessarily expect such a difference?

 

[strmrdr]

Date: 11/7/2008 4:56:22 PM
Author: jasontb
I would expect that it would be quite easy to see the difference between an AGS0 and an AGS3 (as somebody who doesn''t know too much about these grading systems, especially regarding where they break down and lead to inconsistencies).


Am I wrong to necessarily expect such a difference?

In the other thread Garry and myself are in agreement that there would be a large difference.
Jon can settle this when he stops by.
I actually think its twilight zone material to suggest that there is no visible difference between the 2.
Under table leakage stands out like a sore thumb to me.

 

[Regular Guy]

Date: 11/6/2008 9:22:28 PM
Author: Rhino
Isee2 comparison... the order is inversed on this report. The better diamond is on the right and scores a 9.8. Note the hit in ''symmetry'' via the bars too. Another reason I like the Isee2 technology.

I''m sure I misread the meaning here, then, sorry....

 

[Serg]

Date: 11/7/2008 5:01:07 PM
Author: strmrdr

Date: 11/7/2008 4:56:22 PM
Author: jasontb
I would expect that it would be quite easy to see the difference between an AGS0 and an AGS3 (as somebody who doesn''t know too much about these grading systems, especially regarding where they break down and lead to inconsistencies).


Am I wrong to necessarily expect such a difference?

In the other thread Garry and myself are in agreement that there would be a large difference.
Jon can settle this when he stops by.
I actually think its twilight zone material to suggest that there is no visible difference between the 2.
Under table leakage stands out like a sore thumb to me.

two years ago, when we discusses about ASG 4 and GIA Ex, I check several diamonds 41.6-41.8 cr35

I saw difference in leakage , but I saw difference in Life too. ( correlation was negative) . I do not what diamonds are better for my Taste. We disagree with Garry here( I agree what professionals could see difference, but professionals penalty any deviation from P40.75Cr34.5. It is standard Genetic Professional Behavior I prefer be amateur )

 

[Rhino]

Date: 11/7/2008 11:21:28 AM
Author: strmrdr
Thanks Jon...
This is why AGS gold is a very bad thing it would give both those diamonds the same grade.
GIA would also.
HCA would also.

Proportion based systems can''t be used for selection this is a perfect example of that!!!

Agreed on all accounts strm.

 

[strmrdr]

Date: 11/7/2008 5:12:36 PM
Author: Serg

two years ago, when we discusses about ASG 4 and GIA Ex, I check several diamonds 41.6-41.8 cr35

I saw difference in leakage , but I saw difference in Life too. ( correlation was negative) . I do not what diamonds are better for my Taste. We disagree with Garry here( I agree what professionals could see difference, but professionals penalty any deviation from P40.75Cr34.5. It is standard Genetic Professional Behavior I prefer be amateur )

long before I found PS and learned what under table leakage was I rejected dozens of stones just by eye for being to dark under the table when I was shopping for wifey2b's first ER diamond.
Only difference is now I know what caused what I was seeing.