Friendly discussion about bottomless buckets of dazzling ice

[Serg]

Re: Friendly discussion about bottomless buckets of dazzling

I apologize for being late to the party but interestingly enough, while you folks were going back and forth discussing how to tell whether a "crushed ice" radiant has the sharp brilliant crushed ice so many people love versus the "mushy" crushed ice that has deservedly been criticized on this forum, I was discussing exactly the same issue with Pete Yantzer and Jason Quick at the AGS conclave.

The difference between "good" crushed ice and "mushy" crushed ice is pretty obvious when you see the diamonds with your own eyes side by side but how can you tell the difference without that live comparison?

The question plays into the current research being done by the AGS Lab regarding measuring scintillation. Unlike with a round brilliant, the ASET signature of a crushed ice diamond changes substantially with even a small amount of movement so a single static ASET image is far less useful than it is for a round stone.

As a result of our conversation, I sent a bunch of radiants to the Lab for evaluation so we can work together to develope the necessary metrics, which do not currently exist. Hopefully, their research will yield the answers we need to empirically separate the good crushed ice from the bad.

Until then, the reality is that while we can make educated guesses from pictures, ASET images, videos, Sarin scans etc., there is no way to know for sure without seeing the diamond.

Hi Stan,
Would you like send similar bunch of radiants to our cut group with same goals? we have version of Scintillation , Fire metrics and would like tests on good and bad radiant cuts. Movies and photos from these cuts we will publish on cutwise as we did for other cuts .
see sample. http://cutwise.com/stone/6_MSSCUSHION0?format=video360Girdle
if you are interesting send such samples please inform about conditions either me, or Janak, Garry. ( there is 2% import tax for polished diamonds in India now, so we prefer avoid expensive diamonds)

I'd be happy to. How do I contact you?

Great.
please use form http://www.octonus.com/oct/support/SubmitTicket.phtml to contact with me. Fill your email address, send any message , I will answer by email.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

I apologize for being late to the party but interestingly enough, while you folks were going back and forth discussing how to tell whether a "crushed ice" radiant has the sharp brilliant crushed ice so many people love versus the "mushy" crushed ice that has deservedly been criticized on this forum.

So the difference between "mushy" and not "mushy" is the amount of visible scintillation when rocking the stone?

I think that's very good start on the description.
Great work Stan!
I am thrilled to see AGSL considering a methodology that will assist consumers n selecting this type of stone.

Sergey, I love how your stones are presented on the cutwise website. I wish the site had some radiant examples to share then consumers would have a much better understanding of how ASET, IS, and static images correlate to real life viewing.

David, have you had any luck acquiring a dibox? I think that if you could photograph and video many examples of both well, and not so well cut stones, then organise them similar to MSS presentation, that consumers would have a much clearer understanding of what we were seeing, and also for you (and other professionals) to explain to us what we should be looking for. One of the things I've noticed about the past couple threads is how chaotic and disorganised they seem to get. I feel that the average consumer just wants the information to be provided in some sort of standard form (ideally) across all vendors.

Christina,

Done, see first Radiant on cutwise
http://cutwise.com/stone/10_08031095010067?format=video8Fire

Nice work Serg!

This is a great illustration of the difference in how a stone looks when it's video'd setting on its pavilion, versus straight on the the camera

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

I apologize for being late to the party but interestingly enough, while you folks were going back and forth discussing how to tell whether a "crushed ice" radiant has the sharp brilliant crushed ice so many people love versus the "mushy" crushed ice that has deservedly been criticized on this forum, I was discussing exactly the same issue with Pete Yantzer and Jason Quick at the AGS conclave.

The difference between "good" crushed ice and "mushy" crushed ice is pretty obvious when you see the diamonds with your own eyes side by side but how can you tell the difference without that live comparison?

The question plays into the current research being done by the AGS Lab regarding measuring scintillation. Unlike with a round brilliant, the ASET signature of a crushed ice diamond changes substantially with even a small amount of movement so a single static ASET image is far less useful than it is for a round stone.

As a result of our conversation, I sent a bunch of radiants to the Lab for evaluation so we can work together to develope the necessary metrics, which do not currently exist. Hopefully, their research will yield the answers we need to empirically separate the good crushed ice from the bad.

Until then, the reality is that while we can make educated guesses from pictures, ASET images, videos, Sarin scans etc., there is no way to know for sure without seeing the diamond.

Years ago at an AGS conclave Peter talked about counting VFs for princess cuts with negligible ones being the ones that were too small for the human eye to notice. He also seperated VF sizes into Small / Medium and Large.

He also stressed that scintillation is primarily a matter of taste, big, few and slow is not necessarily better than small, many, and fast.
Has anything changed recently? How could there be a subjective scintillation metric in what is otherwise the AGSL objective grading system?

Yes Adelina, Peter Yantzer is nearing retirement as I understand it.
That may indeed bring change.
Also, AGSL current grading system is subjective

Following up on Bryan's question: Aren't trade members obligated to reveal their professional affiliations?

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

I apologize for being late to the party but interestingly enough, while you folks were going back and forth discussing how to tell whether a "crushed ice" radiant has the sharp brilliant crushed ice so many people love versus the "mushy" crushed ice that has deservedly been criticized on this forum, I was discussing exactly the same issue with Pete Yantzer and Jason Quick at the AGS conclave.

The difference between "good" crushed ice and "mushy" crushed ice is pretty obvious when you see the diamonds with your own eyes side by side but how can you tell the difference without that live comparison?

The question plays into the current research being done by the AGS Lab regarding measuring scintillation. Unlike with a round brilliant, the ASET signature of a crushed ice diamond changes substantially with even a small amount of movement so a single static ASET image is far less useful than it is for a round stone.

As a result of our conversation, I sent a bunch of radiants to the Lab for evaluation so we can work together to develope the necessary metrics, which do not currently exist. Hopefully, their research will yield the answers we need to empirically separate the good crushed ice from the bad.

Until then, the reality is that while we can make educated guesses from pictures, ASET images, videos, Sarin scans etc., there is no way to know for sure without seeing the diamond.

Years ago at an AGS conclave Peter talked about counting VFs for princess cuts with negligible ones being the ones that were too small for the human eye to notice. He also seperated VF sizes into Small / Medium and Large.

He also stressed that scintillation is primarily a matter of taste, big, few and slow is not necessarily better than small, many, and fast.
Has anything changed recently? How could there be a subjective scintillation metric in what is otherwise the AGSL objective grading system?

Yes Adelina, Peter Yantzer is nearing retirement as I understand it.
That may indeed bring change.
Also, AGSL current grading system is subjective

Following up on Bryan's question: Aren't trade members obligated to reveal their professional affiliations?

David,
I don't think that is what Adelina meant by her question. But there are plenty of smart people at AGSL, including members of the original team who did the research and developed the LP grading system. Peter is presiding over a smooth transition that I am sure will keep AGSL at the forefront of diamond grading for a long time.

And making a blanket statement that the AGSL LP grading system is "subjective" only damages your credibility.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

If objective measurements are based on subjective suppositions about placement and light direction, that means the grade itself is subjective.
There's nothing "wrong" with a subjective grading system.
Finite Color and clarity grading are also subjective.

Also: I have no doubt there will be an orderly succession at AGSL- but a change in leadership may certainly bring about changes in other things.
AGSL is clearly at the leading edge of cut grading, I agree.
Staying at the forefront of grading will mean tacking this issue.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

Here's a different way to look at this:
"Our world is lit from above" and subsequent conclusions work well for a round diamond.
With many fancy shapes, the supposition leads to conclusions that are inconsistent with real life observations.

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

Here's a different way to look at this:
"Our world is lit from above" and subsequent conclusions work well for a round diamond.
With many fancy shapes, the supposition leads to conclusions that are inconsistent with real life observations.

I would be interested to learn how the world is lit differently for different shapes of diamonds.

Tweezer shots aside, is your world lit from below the horizon?

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

It's more a matter of different types of diamonds use light in different ways Bryan.
I do have a very good feeling of how the differences in light paths translates into a picture.
Which may be why you like to pick on my pictures.
I never put a light behind or below a diamond for my pictures- aside from ViBox pics which get a lot of light behind, and in front of the diamond.

Where do you place the special lights you use for WF pics?

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

I will give you a "hint" Bryan.
A Fancy Shaped "Crushed ice" diamond looks pretty bad when it's laying on it's pavilion- which is the method in the WF glamour shots I've seen.

Have a look at this Radiant in the video where it's facing the camera directly, as compared to the video where it's laying on it's pavilion.
http://cutwise.com/stone/10_08031095010067?format=video8Fire


Although it seems to be a nice looking stone, the shot where it's laying on the pavilion makes the diamond look pretty bad IMO- and it's not relevant to how people will look at the diamond in real life.

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

I will give you a "hint" Bryan.
A Fancy Shaped "Crushed ice" diamond looks pretty bad when it's laying on it's pavilion- which is the method in the WF glamour shots I've seen.

Have a look at this Radiant in the video where it's facing the camera directly, as compared to the video where it's laying on it's pavilion.
http://cutwise.com/stone/10_08031095010067?format=video8Fire


Although it seems to be a nice looking stone, the shot where it's laying on the pavilion makes the diamond look pretty bad IMO- and it's not relevant to how people will look at the diamond in real life.

Thanks for the "hint" David.
You are entitled to your opinions about what does or does not make for good glamour shots and videos. If fancy shapes or crushed ice need light from below the girdle plane to look good that is a discussion we can have. But to bash the AGS LP system because it bases performance on light coming from above the horizon, which is where the predominant amount of light is coming from in normal viewing environments, is not persuasive in my opinion.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

Bryan- truce, ok?
I am not "bashing" the system at this point. Truth is, I've learned a lot through discussions here, and relating to cutters I know.
I'd like the believe my outlook has expanded.

To see why the supposition the world being lit from above does not work for all types of diamonds, we can go back to ASET.
Good crushed ice has lots of green in aset- and scattered leakage.
So it's using light from lower angles as indicated in aset.
The fact that the top of a diamond is rarely parallel to the floor means that in many viewing situations a lot of light will be entering the diamond from the crown facets, and even the pavilion.

This has a far greater effect on real life viewing on a crushed ice stone, as compared to a modern RBC

 

[Rhino]

Re: Friendly discussion about bottomless buckets of dazzling

Argh ... I LOVE THIS DISCUSSION! Sorry I'm late. A study I've been conducting here over the past year is on this very thing and seeing what correlations there are between the technologies vs visual perspective. The correlations exist.

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

Bryan- truce, ok?
I am not "bashing" the system at this point.

To see why the supposition the world being lit from above does not work for all types of diamonds, we can go back to ASET.
Good crushed ice has lots of green in aset- and scattered leakage.
So it's using light from lower angles as indicated in aset.
The fact that the top of a diamond is rarely parallel to the floor means that in many viewing situations a lot of light will be entering the diamond from the crown facets, and even the pavilion.

This has a far greater effect on real life viewing on a crushed ice stone, as compared to a modern RBC

The fact that crushed ice is drawing a lot of light from low angles, that it's scintillation relies in part on positive contrast created by leakage, that its virtual facets are very small, that it has long ray paths that sometimes cause blurry patches of virtual facets, and that it may not perform well at tilt, may say more about the style of cut than about the analytic model. Pretty much everything I am learning in this thread reinforces that view.

When contrasted with a non-crushed ice cushion like Serg's example, we see that a cushion can be cut with a different faceting style that is bright with large crisp virtual facets producing large white and colored sparkles. And these combined qualities are born out in an outstanding ASET signature and presumably in a top AGS LP grade (although Serg did not say if the example had been analysed by AGSL).

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

Jon!!!
Welcome Amigo.


Bryan, no diamond looks great at tilt.
Round diamonds are easier to correlate on the tilt, as the look is so much more consistent from stone to stone, that it's easier to relate what we are seeing.
Plus it's just easier to lay a round on the pavilion.
There's no "wrong" way to do it.
When laying a radiant or cushion on the pavilion it is far more difficult to get the same way twice.

In terms of the model- if you feel cutters should cut to achieve a stone that does well for the existing model, we know what it's going to look like.
You might very well prefer the stone of Sergie's you're referring to- I'm sure there others will agree.
But many will prefer the stone showing the outstanding ASET which I prefer. ( lot's of green dispersed leakage, small patched of dispersed red)
My point is that neither is "right" or "better" ( unless you agree my preference is better )

If the analytic model is expanded to include different styles of cut- which are already popular with consumers for good reason- it will be tremendously helpful for consumers.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

HI Adelina,
If anyone is attacking someone else in this thread, it seems to be you.

I'll admit, I cant find the forum rules for trade members easily.
Identifying ones self in an open discussion where all other trade members are identified seems proper, but stay anonymous, if it's allowed and it pleases you.

I believe that AGSL is indeed doing more work in this area- and Jason's statement only confirms that he feels it's still an open question that needs more work.

And welcome to Pricesope by the way- it somehow seems you've already spent a lot of time here.

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

forum policies can be found here:
https://www.pricescope.com/content/forum-policies

Rule #1 for trade:
Members of trade at minimum must identify themselves to the Pricescope administration with thier personal name and business name. They must also take on the trade badge.

It is aparently not required that they disclose publicly their specific business affiliations.

 

[Karl_K]

Re: Friendly discussion about bottomless buckets of dazzling

While David takes it to an extreme level he is right that the light from above bias of the AGS system has flaws.
Most peoples living rooms for example have the primary lighting from low angles.
The AGS system does not show you how diamonds handle that lighting situation and it should be taken into account when designing a diamond.
That said a diamond that draws light from all lower angles will not be as bright in other lighting situations.
You can use ASET to design inferior diamonds if you get too hung up on it to the exclusion of other factors.
Light from the pavilion is another area that is not as simple as white/black is bad.

I see at times people get so hung up on one system or anti-system to learn what the diamonds are really showing them.

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

While David takes it to an extreme level he is right that the light from above bias of the AGS system has flaws.
Most peoples living rooms for example have the primary lighting from low angles.
The AGS system does not show you how diamonds handle that lighting situation and it should be taken into account when designing a diamond.
That said a diamond that draws light from all lower angles will not be as bright in other lighting situations.
You can use ASET to design inferior diamonds if you get too hung up on it to the exclusion of other factors.
Light from the pavilion is another area that is not as simple as white/black is bad.

I see at times people get so hung up on one system or anti-system to learn what the diamonds are really showing them.

Karl,
Setting aside the actual grade metric for a moment, which I think is the objection of many dealers, especially I would assume for crushed ice, ASET itself does tell you important things about the light handling properties of the diamond. And as such, if understood and properly translated, can be a valuable tool for evaluating remote diamonds - even crushed ice. For instance, the green ASET cushion being discussed is what some knowledgeable dealers call "picture perfect" for this style of cut. Therefore, a buyer could look for diamonds with this ASET signature if they want a bottomless buckets of dazzling ice cut. If they want a non-crushed ice cushion shape that is a top cut of it's style they could look for stones with an ASET signature like Serg's.

A consumer doesn't necessarily need to know why a predominantly green signature with well distributed leakage "works" in creating a nice crushed ice look. They just need to know that it does work to be able identify candidates for further evaluation, if this flavor is to their taste.

I would guess that AGSL has more work to do in refining the evaluation and grading of crushed ice and different styles of fancies. And from Stan's comments it looks like that research is ongoing. But the fact that we are still in early stages of developing generally acceptable grading standards does not necessarily impugn the theory or negate the value of the ASET tool. Like any other good tool ever created, you have to use it properly for it to be valuable.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

Karl – you, if anyone have seen my position evolve.
I would not be backed into a corner the discussion could be more informative. I have nothing against Ideal cut- or stones cut for LP
I love a lot of designs that are cut for AGSL LP standards. Not all though which is one reason I feel the current grades are subjective.
We just need more inclusivity in identifying different optical signatures being rewarded for meeting different goals.
Bryan - I agree that ASET is a valuable tool and can be effectively used to identify good candidates.
Education is the key. Red is not better. Green is not better. Balanced leakage is good.in some cases . Each color can help identify different flavor of stones.
I also believe the issues of photography make the ASET even more important. Particularly on sites using stones photographed on the pavilion.

 

[Serg]

Re: Friendly discussion about bottomless buckets of dazzling

Bryan- truce, ok?
I am not "bashing" the system at this point.

To see why the supposition the world being lit from above does not work for all types of diamonds, we can go back to ASET.
Good crushed ice has lots of green in aset- and scattered leakage.
So it's using light from lower angles as indicated in aset.
The fact that the top of a diamond is rarely parallel to the floor means that in many viewing situations a lot of light will be entering the diamond from the crown facets, and even the pavilion.

This has a far greater effect on real life viewing on a crushed ice stone, as compared to a modern RBC

The fact that crushed ice is drawing a lot of light from low angles, that it's scintillation relies in part on positive contrast created by leakage, that its virtual facets are very small, that it has long ray paths that sometimes cause blurry patches of virtual facets, and that it may not perform well at tilt, may say more about the style of cut than about the analytic model. Pretty much everything I am learning in this thread reinforces that view.

When contrasted with a non-crushed ice cushion like Serg's example, we see that a cushion can be cut with a different faceting style that is bright with large crisp virtual facets producing large white and colored sparkles. And these combined qualities are born out in an outstanding ASET signature and presumably in a top AGS LP grade (although Serg did not say if the example had been analysed by AGSL).

Bryan,
this cut/ diamond we did not send to AGSL and we have not any plans to send this or any other our diamonds to AGSL .
also we did not use ASG PGS software for this cut.( 5-10 years ago we tested AGS PGS software on some MSS diamonds, results was not interesting , it was just helpless for our work).
For my "Taste " this design has too much red in ASET. I prefer better balance between Red and Green, I like to mix Green and Red but its very to difficult achieve without leakage. each solution ( a lot of Red and Red+significant Green+ some leakage ) has advantages and disadvantages . we did not find any solution without disadvantages yet( there is not Ideal cut). In this case we selected design with a lot of Red, in next time we will select Red+Green( we recently did such design for Emerald corners and it looks very promised )

But the fact that we are still in early stages of developing generally acceptable grading standards does not necessarily impugn the theory or negate the value of the ASET tool. Like any other good tool ever created, you have to use it properly for it to be valuable.

exactly. ASET is one of other Tools. this tool is suitable for production quality control ( easy to see difference between sample and current diamond). it can be used for selection/rejection process ( if you find good reference diamonds by different way).
But it is not good to grade LP at all. the problem is that many on PS use it as grading tool and push others to do same .

Good enough round cut proportions has been found before AGS cut study. Good enough fancy cuts and fancy cut proportions had not been found before AGS cut study( may be except princess cut).
It is reason they AGS system works for round cut and does not work for most fancy cuts.

BTW, in our work we use modified ASET( better to say modified Al Gilbertson scope) with 4 color zones + Body obscuration blue zone . Also we always check cut candidates from left, right eye directions( left/right 5 degree tilt), it is very important to evaluate Blue zones

 

[Karl_K]

Re: Friendly discussion about bottomless buckets of dazzling

While David takes it to an extreme level he is right that the light from above bias of the AGS system has flaws.
Most peoples living rooms for example have the primary lighting from low angles.
The AGS system does not show you how diamonds handle that lighting situation and it should be taken into account when designing a diamond.
That said a diamond that draws light from all lower angles will not be as bright in other lighting situations.
You can use ASET to design inferior diamonds if you get too hung up on it to the exclusion of other factors.
Light from the pavilion is another area that is not as simple as white/black is bad.

I see at times people get so hung up on one system or anti-system to learn what the diamonds are really showing them.

Karl,
Setting aside the actual grade metric for a moment, which I think is the objection of many dealers, especially I would assume for crushed ice, ASET itself does tell you important things about the light handling properties of the diamond. And as such, if understood and properly translated, can be a valuable tool for evaluating remote diamonds - even crushed ice. For instance, the green ASET cushion being discussed is what some knowledgeable dealers call "picture perfect" for this style of cut. Therefore, a buyer could look for diamonds with this ASET signature if they want a bottomless buckets of dazzling ice cut. If they want a non-crushed ice cushion shape that is a top cut of it's style they could look for stones with an ASET signature like Serg's.

A consumer doesn't necessarily need to know why a predominantly green signature with well distributed leakage "works" in creating a nice crushed ice look. They just need to know that it does work to be able identify candidates for further evaluation, if this flavor is to their taste.

I would guess that AGSL has more work to do in refining the evaluation and grading of crushed ice and different styles of fancies. And from Stan's comments it looks like that research is ongoing. But the fact that we are still in early stages of developing generally acceptable grading standards does not necessarily impugn the theory or negate the value of the ASET tool. Like any other good tool ever created, you have to use it properly for it to be valuable.

I would agree that ASET is useful, but I caution about getting to hung up on it is all.
It is one of the better tools for remote evaluation of many diamonds.
Understanding the interpretation and knowing what it does not tell you is just as important as knowing what it does tell you.
With complex fancies there is a lot to be leaned yet and it does not do as well as with rounds.
That said it can be used to point one in a decent direction on many designs but is less useful for choosing among the top contenders.
Or in other words reasonable interpretation can help eliminate the worst of the bunch.
What is missing from many cuts is what defines reasonable interpretation.

 

[Karl_K]

Re: Friendly discussion about bottomless buckets of dazzling

Karl – you, if anyone have seen my position evolve.

That is true.

 

[diagem]

Re: Friendly discussion about bottomless buckets of dazzling

Bryan- truce, ok?
I am not "bashing" the system at this point.

To see why the supposition the world being lit from above does not work for all types of diamonds, we can go back to ASET.
Good crushed ice has lots of green in aset- and scattered leakage.
So it's using light from lower angles as indicated in aset.
The fact that the top of a diamond is rarely parallel to the floor means that in many viewing situations a lot of light will be entering the diamond from the crown facets, and even the pavilion.

This has a far greater effect on real life viewing on a crushed ice stone, as compared to a modern RBC

The fact that crushed ice is drawing a lot of light from low angles, that it's scintillation relies in part on positive contrast created by leakage, that its virtual facets are very small, that it has long ray paths that sometimes cause blurry patches of virtual facets, and that it may not perform well at tilt, may say more about the style of cut than about the analytic model. Pretty much everything I am learning in this thread reinforces that view.

When contrasted with a non-crushed ice cushion like Serg's example, we see that a cushion can be cut with a different faceting style that is bright with large crisp virtual facets producing large white and colored sparkles. And these combined qualities are born out in an outstanding ASET signature and presumably in a top AGS LP grade (although Serg did not say if the example had been analysed by AGSL).

Bryan,
this cut/ diamond we did not send to AGSL and we have not any plans to send this or any other our diamonds to AGSL .
also we did not use ASG PGS software for this cut.( 5-10 years ago we tested AGS PGS software on some MSS diamonds, results was not interesting , it was just helpless for our work).
For my "Taste " this design has too much red in ASET. I prefer better balance between Red and Green, I like to mix Green and Red but its very to difficult achieve without leakage. each solution ( a lot of Red and Red+significant Green+ some leakage ) has advantages and disadvantages . we did not find any solution without disadvantages yet( there is not Ideal cut). In this case we selected design with a lot of Red, in next time we will select Red+Green( we recently did such design for Emerald corners and it looks very promised )

But the fact that we are still in early stages of developing generally acceptable grading standards does not necessarily impugn the theory or negate the value of the ASET tool. Like any other good tool ever created, you have to use it properly for it to be valuable.

exactly. ASET is one of other Tools. this tool is suitable for production quality control ( easy to see difference between sample and current diamond). it can be used for selection/rejection process ( if you find good reference diamonds by different way).
But it is not good to grade LP at all. the problem is that many on PS use it as grading tool and push others to do same .

Good enough round cut proportions has been found before AGS cut study. Good enough fancy cuts and fancy cut proportions had not been found before AGS cut study( may be except princess cut).
It is reason they AGS system works for round cut and does not work for most fancy cuts.

BTW, in our work we use modified ASET( better to say modified Al Gilbertson scope) with 4 color zones + Body obscuration blue zone . Also we always check cut candidates from left, right eye directions( left/right 5 degree tilt), it is very important to evaluate Blue zones

Sergey,
Interesting about not sending to AGSL, may I ask which grading laboratory you use for marketing on cutwise? I hope I am not being nosy but if there are other candidates for optical symmetry grading who are open to innovations I will be happy to learn about.

Interestingly is reading about your RED-GREEN preference in some designs. I redesigned an oldcut a few years ago that is actually based on RED (face-up) GREEN (tilt) play of light. AGSL deducted 0.70 for brightness (thus grading it a 1) based on its green tilt results. AGSL supplied us with some other angle combinations so we would be able to achieve the 0 LP grade (by producing it more RED) but it meant altering our design too much. I decided against the altering as I believe it didnt necessarily would make it a more beautiful Diamond than what it is already.

While I fully agree with you that AGSL grading system favors round cuts and their grading advancements for fancies is problematic but so are all the tools & technologies available presently to cutters. Optical symmetry cutting for fancy shapes is still in its early stages. it would be nice to find a new laboratory who has the interest to collaborate on the future of fancy cuts.

Can you show examples of this modified Al Gilbertson scope?

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

Sergey,
Interesting about not sending to AGSL, may I ask which grading laboratory you use for marketing on cutwise? I hope I am not being nosy but if there are other candidates for optical symmetry grading who are open to innovations I will be happy to learn about.

Interestingly is reading about your RED-GREEN preference in some designs. I redesigned an oldcut a few years ago that is actually based on RED (face-up) GREEN (tilt) play of light. AGSL deducted 0.70 for brightness (thus grading it a 1) based on its green tilt results. AGSL supplied us with some other angle combinations so we would be able to achieve the 0 LP grade (by producing it more RED) but it meant altering our design too much. I decided against the altering as I believe it didnt necessarily would make it a more beautiful Diamond than what it is already.

While I fully agree with you that AGSL grading system favors round cuts and their grading advancements for fancies is problematic but so are all the tools & technologies available presently to cutters. Optical symmetry cutting for fancy shapes is still in its early stages. it would be nice to find a new laboratory who has the interest to collaborate on the future of fancy cuts.

Can you show examples of this modified Al Gilbertson scope?

Yoram, I believe the part in bold is relevant to the discussion.
Part of my issue with current LP standards is that many cutters ( not you) are going to forget beauty, and simply cut for the current LP standards- which I've said many times seem to be too restrictive.
Cutting for beauty produces different types of stones than cutting for LP in many cases.
Cutting to try to get more red in an ASET versus cutting to produce a more beautiful diamond seems problematic to me

 

[Serg]

Re: Friendly discussion about bottomless buckets of dazzling

Bryan- truce, ok?
I am not "bashing" the system at this point.

To see why the supposition the world being lit from above does not work for all types of diamonds, we can go back to ASET.
Good crushed ice has lots of green in aset- and scattered leakage.
So it's using light from lower angles as indicated in aset.
The fact that the top of a diamond is rarely parallel to the floor means that in many viewing situations a lot of light will be entering the diamond from the crown facets, and even the pavilion.

This has a far greater effect on real life viewing on a crushed ice stone, as compared to a modern RBC

The fact that crushed ice is drawing a lot of light from low angles, that it's scintillation relies in part on positive contrast created by leakage, that its virtual facets are very small, that it has long ray paths that sometimes cause blurry patches of virtual facets, and that it may not perform well at tilt, may say more about the style of cut than about the analytic model. Pretty much everything I am learning in this thread reinforces that view.

When contrasted with a non-crushed ice cushion like Serg's example, we see that a cushion can be cut with a different faceting style that is bright with large crisp virtual facets producing large white and colored sparkles. And these combined qualities are born out in an outstanding ASET signature and presumably in a top AGS LP grade (although Serg did not say if the example had been analysed by AGSL).

Bryan,
this cut/ diamond we did not send to AGSL and we have not any plans to send this or any other our diamonds to AGSL .
also we did not use ASG PGS software for this cut.( 5-10 years ago we tested AGS PGS software on some MSS diamonds, results was not interesting , it was just helpless for our work).
For my "Taste " this design has too much red in ASET. I prefer better balance between Red and Green, I like to mix Green and Red but its very to difficult achieve without leakage. each solution ( a lot of Red and Red+significant Green+ some leakage ) has advantages and disadvantages . we did not find any solution without disadvantages yet( there is not Ideal cut). In this case we selected design with a lot of Red, in next time we will select Red+Green( we recently did such design for Emerald corners and it looks very promised )

But the fact that we are still in early stages of developing generally acceptable grading standards does not necessarily impugn the theory or negate the value of the ASET tool. Like any other good tool ever created, you have to use it properly for it to be valuable.

exactly. ASET is one of other Tools. this tool is suitable for production quality control ( easy to see difference between sample and current diamond). it can be used for selection/rejection process ( if you find good reference diamonds by different way).
But it is not good to grade LP at all. the problem is that many on PS use it as grading tool and push others to do same .

Good enough round cut proportions has been found before AGS cut study. Good enough fancy cuts and fancy cut proportions had not been found before AGS cut study( may be except princess cut).
It is reason they AGS system works for round cut and does not work for most fancy cuts.

BTW, in our work we use modified ASET( better to say modified Al Gilbertson scope) with 4 color zones + Body obscuration blue zone . Also we always check cut candidates from left, right eye directions( left/right 5 degree tilt), it is very important to evaluate Blue zones

Sergey,
Interesting about not sending to AGSL, may I ask which grading laboratory you use for marketing on cutwise? I hope I am not being nosy but if there are other candidates for optical symmetry grading who are open to innovations I will be happy to learn about.

Interestingly is reading about your RED-GREEN preference in some designs. I redesigned an oldcut a few years ago that is actually based on RED (face-up) GREEN (tilt) play of light. AGSL deducted 0.70 for brightness (thus grading it a 1) based on its green tilt results. AGSL supplied us with some other angle combinations so we would be able to achieve the 0 LP grade (by producing it more RED) but it meant altering our design too much. I decided against the altering as I believe it didnt necessarily would make it a more beautiful Diamond than what it is already.

While I fully agree with you that AGSL grading system favors round cuts and their grading advancements for fancies is problematic but so are all the tools & technologies available presently to cutters. Optical symmetry cutting for fancy shapes is still in its early stages. it would be nice to find a new laboratory who has the interest to collaborate on the future of fancy cuts.

Can you show examples of this modified Al Gilbertson scope?

Yoram,
1) we do not use Lab reports for marketing. For clarity, colour, origin we use GIA. For craftsmanship we use HP reports and we are planing to add optical symmetry reports for fancy cuts in several months.
2) Cutwise clients may use reports from any lab.
3) One of Cutwise's goals is to give possibility to compare different cuts in the same realistic light environments. Then it will be possible for a buyer to distinguish under- and overperformance within the same grading group and pick up better performing stones. This will result in commanding premium/increased liquidity of added-value diamonds.

 

[Serg]

Re: Friendly discussion about bottomless buckets of dazzling

Can you show examples of this modified Al Gilbertson scope?

Yoram,

see images for Round cuts
1) ASET with Blue, Red, Light Green, Dark Green Zones
2) Radial Zone Light

 

[diagem]

Re: Friendly discussion about bottomless buckets of dazzling

Bryan- truce, ok?
I am not "bashing" the system at this point.

To see why the supposition the world being lit from above does not work for all types of diamonds, we can go back to ASET.
Good crushed ice has lots of green in aset- and scattered leakage.
So it's using light from lower angles as indicated in aset.
The fact that the top of a diamond is rarely parallel to the floor means that in many viewing situations a lot of light will be entering the diamond from the crown facets, and even the pavilion.

This has a far greater effect on real life viewing on a crushed ice stone, as compared to a modern RBC

The fact that crushed ice is drawing a lot of light from low angles, that it's scintillation relies in part on positive contrast created by leakage, that its virtual facets are very small, that it has long ray paths that sometimes cause blurry patches of virtual facets, and that it may not perform well at tilt, may say more about the style of cut than about the analytic model. Pretty much everything I am learning in this thread reinforces that view.

When contrasted with a non-crushed ice cushion like Serg's example, we see that a cushion can be cut with a different faceting style that is bright with large crisp virtual facets producing large white and colored sparkles. And these combined qualities are born out in an outstanding ASET signature and presumably in a top AGS LP grade (although Serg did not say if the example had been analysed by AGSL).

Bryan,
this cut/ diamond we did not send to AGSL and we have not any plans to send this or any other our diamonds to AGSL .
also we did not use ASG PGS software for this cut.( 5-10 years ago we tested AGS PGS software on some MSS diamonds, results was not interesting , it was just helpless for our work).
For my "Taste " this design has too much red in ASET. I prefer better balance between Red and Green, I like to mix Green and Red but its very to difficult achieve without leakage. each solution ( a lot of Red and Red+significant Green+ some leakage ) has advantages and disadvantages . we did not find any solution without disadvantages yet( there is not Ideal cut). In this case we selected design with a lot of Red, in next time we will select Red+Green( we recently did such design for Emerald corners and it looks very promised )

But the fact that we are still in early stages of developing generally acceptable grading standards does not necessarily impugn the theory or negate the value of the ASET tool. Like any other good tool ever created, you have to use it properly for it to be valuable.

exactly. ASET is one of other Tools. this tool is suitable for production quality control ( easy to see difference between sample and current diamond). it can be used for selection/rejection process ( if you find good reference diamonds by different way).
But it is not good to grade LP at all. the problem is that many on PS use it as grading tool and push others to do same .

Good enough round cut proportions has been found before AGS cut study. Good enough fancy cuts and fancy cut proportions had not been found before AGS cut study( may be except princess cut).
It is reason they AGS system works for round cut and does not work for most fancy cuts.

BTW, in our work we use modified ASET( better to say modified Al Gilbertson scope) with 4 color zones + Body obscuration blue zone . Also we always check cut candidates from left, right eye directions( left/right 5 degree tilt), it is very important to evaluate Blue zones

Sergey,
Interesting about not sending to AGSL, may I ask which grading laboratory you use for marketing on cutwise? I hope I am not being nosy but if there are other candidates for optical symmetry grading who are open to innovations I will be happy to learn about.

Interestingly is reading about your RED-GREEN preference in some designs. I redesigned an oldcut a few years ago that is actually based on RED (face-up) GREEN (tilt) play of light. AGSL deducted 0.70 for brightness (thus grading it a 1) based on its green tilt results. AGSL supplied us with some other angle combinations so we would be able to achieve the 0 LP grade (by producing it more RED) but it meant altering our design too much. I decided against the altering as I believe it didnt necessarily would make it a more beautiful Diamond than what it is already.

While I fully agree with you that AGSL grading system favors round cuts and their grading advancements for fancies is problematic but so are all the tools & technologies available presently to cutters. Optical symmetry cutting for fancy shapes is still in its early stages. it would be nice to find a new laboratory who has the interest to collaborate on the future of fancy cuts.

Can you show examples of this modified Al Gilbertson scope?

Yoram,
1) we do not use Lab reports for marketing. For clarity, colour, origin we use GIA. For craftsmanship we use HP reports and we are planing to add optical symmetry reports for fancy cuts in several months.
2) Cutwise clients may use reports from any lab.
3) One of Cutwise's goals is to give possibility to compare different cuts in the same realistic light environments. Then it will be possible for a buyer to distinguish under- and overperformance within the same grading group and pick up better performing stones. This will result in commanding premium/increased liquidity of added-value diamonds.

Sounds like an interesting platform, it would be interesting to see how it can function without a third party Laboratory focusing on LP or play of light type grading..., it would be nice to see your addition of optical symmetry reports for fancy shapes.
But whoever would want to participate on cutwise will need a ViBox/DiBox in order to submit Diamonds?

 

[diagem]

Re: Friendly discussion about bottomless buckets of dazzling

Can you show examples of this modified Al Gilbertson scope?

Yoram,

see images for Round cuts
1) ASET with Blue, Red, Light Green, Dark Green Zones
2) Radial Zone Light

I looked for some info online, can you explain more on its functionality and why you prefer It over ASET for your use?

Thank you Sergey.

 

[Serg]

Re: Friendly discussion about bottomless buckets of dazzling

Can you show examples of this modified Al Gilbertson scope?

Yoram,

see images for Round cuts
1) ASET with Blue, Red, Light Green, Dark Green Zones
2) Radial Zone Light

I looked for some info online, can you explain more on its functionality and why you prefer It over ASET for your use?

Thank you Sergey.

Yoram,

ETAS shows light source direction which cut uses.( redirect to a observer ). Good cut redirects light from many directions. ( minimises blind zones) . in same time bad cut can also redirect light from many direction. Take for example "Nail Head" round cut.
the difference between bad and cuts how they mix Light directions in cut pattern . for Good cuts each zone( 10-20% of surface) of pattern has to redirect light from quite different directions . I use Zone structure light for checking how well cut mix light directions.
It is very easy to optimize cut for low leakage . most difficult task for cut designers:
1) minimisation of Blind zones in ETAS space
2) Good mixing light direction in cut pattern
3) avoiding same light direction for left and right eyes. Ideally when "same VF" redirect light from quite different directions to left and right eyes in same time ( double ETAS).( of course left and right eyes can not have exactly same VF's pattern)

for example it is very important that cut shares Observer reflection between different cut zones and only few VFs reflect observer to left and right eyes in same time. Otherwise Observer create "Dead zones" as "Nail head"

But whoever would want to participate on cutwise will need a ViBox/DiBox in order to submit Diamonds?

Indian cutters can send diamonds to Surat, Mumbai service centres. Sorry, we have not yet partners for such service in other countries.

 

[JoshuaNiamehr]

Re: Friendly discussion about bottomless buckets of dazzling

Can you show examples of this modified Al Gilbertson scope?

Yoram,

see images for Round cuts
1) ASET with Blue, Red, Light Green, Dark Green Zones
2) Radial Zone Light

I looked for some info online, can you explain more on its functionality and why you prefer It over ASET for your use?

Thank you Sergey.

Yoram,

ETAS shows light source direction which cut uses.( redirect to a observer ). Good cut redirects light from many directions. ( minimises blind zones) . in same time bad cut can also redirect light from many direction. Take for example "Nail Head" round cut.
the difference between bad and cuts how they mix Light directions in cut pattern . for Good cuts each zone( 10-20% of surface) of pattern has to redirect light from quite different directions . I use Zone structure light for checking how well cut mix light directions.
It is very easy to optimize cut for low leakage . most difficult task for cut designers:
1) minimisation of Blind zones in ETAS space
2) Good mixing light direction in cut pattern
3) avoiding same light direction for left and right eyes. Ideally when "same VF" redirect light from quite different directions to left and right eyes in same time ( double ETAS).( of course left and right eyes can not have exactly same VF's pattern)

for example it is very important that cut shares Observer reflection between different cut zones and only few VFs reflect observer to left and right eyes in same time. Otherwise Observer create "Dead zones" as "Nail head"

But whoever would want to participate on cutwise will need a ViBox/DiBox in order to submit Diamonds?

Indian cutters can send diamonds to Surat, Mumbai service centres. Sorry, we have not yet partners for such service in other countries.

Serg,

We've sent two polisher partners over so far but never heard about a few of the other services - who would be the right person to talk to?

Joshua