Peter Yantzer on diamond cutting

[WinkHPD]

This is the first of several exerpts from Peter Yantzer''s presentation on Tuesday.

In this first segment Peter had us list our favorite in this picture, starting with 1 in the upper left hand corner counting across so that 1 @ 2 are in the top row, 3, 4, 5 in the second row and 6, 7 are in the bottom row.

Then he had us list our least favorite picture.

Then we handed in the paper and the vote tallied.

Do this BEFORE you watch the video. I am enclosing the picture as the duratrans did not show at all in the video except as a big white glare...

I will put the video in the next mail to help you not be tempted to cheat...

Wink

 

[WinkHPD]

It was an interesting excersize, diamonds 1 and 3 were neck and neck in the voting for favorite with only one vote separating them, and # 4 was nearly unanimous in being the least favorite diamond.

In this segment, Peter explains why.

Wink

 

[strmrdr]

I knew 4 was going to be the least favorite but I wouldn't pick a favorite because they arent all face up.

I must agree that contrast is very very important, so much so I wrote my first PS article about it.

 

[WinkHPD]

There is some very good stuff coming when I finally get time to finish editing the presentation into bite sized pieces. Turns out that there is a definite advantage to good optical symmetry, I bet you can even guess why.

Wink

 

[strmrdr]

symmetrical contrast patterns being pleasing would be the first.

Would be interesting if they nailed down a scint. advantage.
A lot of people feel there is one but it is hard to prove.

 

[WinkHPD]

Date: 4/23/2009 8:43:07 PM
Author: strmrdr
symmetrical contrast patterns being pleasing would be the first.


Would be interesting if they nailed down a scint. advantage.

A lot of people feel there is one but it is hard to prove.

Pleasing is part of it of course, but according to the research that Peter discusses later in the presentation the size of the virtual facets is increased with optical symmetry which results in more visible events. It will probably be Sat or Sunday before I can devote more time to editing the presentation into four to five minute chunks, but I think you will enjoy what he has to say.

Wink

 

[strmrdr]

Date: 4/24/2009 12:06:31 AM
Author: Wink

Date: 4/23/2009 8:43:07 PM

Author: strmrdr

symmetrical contrast patterns being pleasing would be the first.



Would be interesting if they nailed down a scint. advantage.


A lot of people feel there is one but it is hard to prove.

Pleasing is part of it of course, but according to the research that Peter discusses later in the presentation the size of the virtual facets is increased with optical symmetry which results in more visible events. It will probably be Sat or Sunday before I can devote more time to editing the presentation into four to five minute chunks, but I think you will enjoy what he has to say.


Wink

interesting, would like to hear his exact words because it does not always increase the size of the VF''s
It depends on what is off.
I am looking forward to it.

 

[strmrdr]

Thinking some more about it, saying that it often or usually increases the VF size would be correct.
I have seen exceptions however.

I will have to dig thru my gem file collection.

 

[Todd Gray]

Peter Yantzer''s explanation on visual performance and virtual facets was truly fascinating and insightful. I''m really happy that I was present to hear it! Such a treat!

Realize that all of the diamonds featured on the Duratrans picture shown above are Infinity Diamonds and they are essentially equal in terms of visual performance and cut quality. What is causing people to see a difference in contrast between the diamonds is partly due to the angle of the diamonds as pictured in the photograph, but also partly due to photo editing intended to display the diamonds at different depths of tonal value. So while we find ourselves attracted to a certain diamond in the mix as pictured at this angle, etc. it is likely that we would find it more difficult to discern between the optical properties of the diamonds if we were comparing them from the same vantage point and angle of observation... Strmrdr definitely picked up on this

 

[diagem]

Date: 4/24/2009 12:06:31 AM
Author: Wink

Date: 4/23/2009 8:43:07 PM
Author: strmrdr
symmetrical contrast patterns being pleasing would be the first.


Would be interesting if they nailed down a scint. advantage.

A lot of people feel there is one but it is hard to prove.

Pleasing is part of it of course, but according to the research that Peter discusses later in the presentation the size of the virtual facets is increased with optical symmetry which results in more visible events. It will probably be Sat or Sunday before I can devote more time to editing the presentation into four to five minute chunks, but I think you will enjoy what he has to say.

Wink

Hi Wink...

You (or Peter I should say) managed to confuse me a bit.
I would tend to understand that an ''optical symmetry'' would result in increased visible events....
But doesnt this contradicts the fact: that ''virtual facets size is increased with optical symmetry''?

 

[Stephan]

When virtual facets size is bigger, there are more visible events.
Too much little virtual facets won''t result in visible events.
I don''t see any contradiction?

 

[strmrdr]

Date: 4/24/2009 2:32:29 AM
Author: DiaGem
Hi Wink...


You (or Peter I should say) managed to confuse me a bit.

I would tend to understand that an 'optical symmetry' would result in increased visible events....

But doesnt this contradicts the fact: that 'virtual facets size is increased with optical symmetry'?

There would be fewer but larger events.
When events get to small they are not visible according to AGS theory(I somewhat disagree it is more complicated than that)
So fewer but larger events could result in more visible events if you buy into the theory.
I don't think it is that simple(diamond size can make a huge difference) but in some cases they are correct.
Keep in mind I haven't seen the latest presentation so they may have figured out how to account for this.

In a 2ct diamond for example the resulting smaller VF's could lead to far more visible flashes where the same in a 1/2ct would lead to less.

 

[Garry H (Cut Nut)]

in 10ct plus bad symmetry or extra facets can be a benefit in round diamonds.

 

[strmrdr]

Date: 4/24/2009 3:35:03 AM
Author: Garry H (Cut Nut)
in 10ct plus bad symmetry or extra facets can be a benefit in round diamonds.

That high?
I start liking extra facet cuts at around 2.5ct to 3ct.
The 57s are ok at that size also so I can see setting the number higher I guess.

 

[Garry H (Cut Nut)]

Date: 4/24/2009 3:40:41 AM
Author: strmrdr

Date: 4/24/2009 3:35:03 AM
Author: Garry H (Cut Nut)
in 10ct plus bad symmetry or extra facets can be a benefit in round diamonds.

That high?
I start liking extra facet cuts at around 2.5ct to 3ct.
The 57s are ok at that size also so I can see setting the number higher I guess.

for a change I was not trying to start a debate

 

[diagem]

Date: 4/24/2009 2:41:52 AM
Author: QueenMum
When virtual facets size is bigger, there are more visible events.
Too much little virtual facets won''t result in visible events.
I don''t see any contradiction?

Ok..., so I still dont get how would ''optical symmetry'' make the virtual facets bigger..., wouldnt it depend on the faceting arrangement and type in combination with its size and angle placement?

Maybe the correct word to use would be "uniform" rather than bigger/larger?

 

[diagem]

Date: 4/24/2009 2:53:41 AM
Author: strmrdr

Date: 4/24/2009 2:32:29 AM
Author: DiaGem
Hi Wink...


You (or Peter I should say) managed to confuse me a bit.

I would tend to understand that an 'optical symmetry' would result in increased visible events....

But doesnt this contradicts the fact: that 'virtual facets size is increased with optical symmetry'?

There would be fewer but larger events.
When events get to small they are not visible according to AGS theory(I somewhat disagree it is more complicated than that)
So fewer but larger events could result in more visible events if you buy into the theory.
I don't think it is that simple(diamond size can make a huge difference) but in some cases they are correct.
Keep in mind I haven't seen the latest presentation so they may have figured out how to account for this.

In a 2ct diamond for example the resulting smaller VF's could lead to far more visible flashes where the same in a 1/2ct would lead to less.

I am with you on that...

But I dont understand where the optical symmetry = larger VF's come from?

I am not trying to start a debate either..., just want to understand the root of this fact....

 

[Lorelei]

Good stuff, thanks Wink!!

 

[Stephan]

Date: 4/24/2009 6:16:37 AM
Author: DiaGem

Date: 4/24/2009 2:41:52 AM
Author: QueenMum
When virtual facets size is bigger, there are more visible events.
Too much little virtual facets won''t result in visible events.
I don''t see any contradiction?

Ok..., so I still dont get how would ''optical symmetry'' make the virtual facets bigger..., wouldnt it depend on the faceting arrangement and type in combination with its size and angle placement?

Maybe the correct word to use would be ''uniform'' rather than bigger/larger?

I guess if the facets are badly aligned, there will be more virtual facets and they will be smaller.

 

[strmrdr]

In this example some are larger but overall there are more smaller ones.
The one on the left is based on a real diamonds scan.

 

[strmrdr]

One of the first things to happen is for the mains(arrow shafts) to split into smaller VF's when optical symmetry goes wonky.
They are the largest VF's on a RB.

 

[strmrdr]

Here are arrows pointing to the splits.

 

[diagem]

Date: 4/24/2009 9:00:21 AM
Author: strmrdr
In this example some are larger but overall there are more smaller ones.
The one on the left is based on a real diamonds scan.

I see..., but I do notice larger VF''s on the real diamond scan as when comparing to the virtual one...

I think both comparisons should be done on an actual Diamond scans with same numbers (if even possible)..., virtual Diamonds are too perfect! (and as we all know..., there is no perfect...

)

BTW..., the close up images are not of the same scan as the real diamond scan above?

 

[strmrdr]

Date: 4/24/2009 10:13:59 AM
Author: DiaGem



BTW..., the close up images are not of the same scan as the real diamond scan above?

correct it is a different real diamond scan

The virtual diamond on the right is a model with the same average angles.

What is interesting is when the diamond is tilted.
Step cuts react differently than brilliants.
RBs VFs get smaller with tilt, with step cuts they get larger.
The reason being that the RB''s pavilion facets are long and narrow and the step cuts are short and wide.
It totally changes the behavior.
This can get real interesting when optical symmetry is off.
Which is why I am so interested in what he has to say.
VFs is an incredibly complex subject that is the heart of diamond design.

 

[diagem]

Date: 4/24/2009 10:28:01 AM
Author: strmrdr

Date: 4/24/2009 10:13:59 AM
Author: DiaGem



BTW..., the close up images are not of the same scan as the real diamond scan above?

correct it is a different real diamond scan

The virtual diamond on the right is a model with the same average angles.

What is interesting is when the diamond is tilted.
Step cuts react differently than brilliants.
RBs VFs get smaller with tilt, with step cuts they get larger.
The reason being that the RB''s pavilion facets are long and narrow and the step cuts are short and wide.
It totally changes the behavior.
This can get real interesting when optical symmetry is off.
Which is why I am so interested in what he has to say.
VFs is an incredibly complex subject that is the heart of diamond design.

Sure..., its what I call charm/character..., and what many of you Pser''s out there love in Antique Cuts....

 

[WinkHPD]

Date: 4/23/2009 8:02:07 PM
Author: Wink
There is some very good stuff coming when I finally get time to finish editing the presentation into bite sized pieces. Turns out that there is a definite advantage to good optical symmetry, I bet you can even guess why.

Wink

I have perhaps mispoken in the above quote. I think I should have said something more along the line of "Turns out that there are definite observable changes to the look of a diamond with good optical symmetry". While AGS does tell us what these are, they do not tell us whether or not these are advantages. My interpretation and the interpretation of others who like that look will call them advantages, AGS is very careful not to lable them.

In this segment, Peter talks about taste and a also about where we are.

Wink

 

[strmrdr]

Date: 4/25/2009 4:17:49 PM
Author: Wink

Date: 4/23/2009 8:02:07 PM
In this segment, Peter talks about taste and a also about where we are.


Wink

interesting.
At its heart cut grading today is this range of diamonds is what many people find beautiful how does this combination compare and sorts them into groups.
I actually like better how Garry handles it with the HCA where he narrows it down by bic, fic, tic then separated into earring/pendant and ring stone and finds the diamonds with the best potential to be beautiful in each group.
There are some very beautiful combos left out of the lab grading system because they lack such a sorting feature.

I see not taking taste and usage into account more as a weakness of the lab systems.
The reason it isn't is that for the average jeweler it is a marketing nightmare.
The don't have a Lorelei to explain it over and over and over.

I don't disagree with what Peter said because he is right, I just see it differently and what would happen in a perfect world.
I don't have to try and get cutters to use my type of system which makes a world of difference.

 

[diagem]

What was Peter''s last sentence in this video?
I had a hard time understanding although I replayed it a few times.

Thanks,

 

[WinkHPD]

In this video both Peter Yantzer and Paul Slegers of Infinity Diamonds talk about the importance of weight ratio

http://www.screencast.com/t/fDyvyMDw

It is not too long, but the next one, it is too long, about 28 minutes. It is rendering and uploading it may be an hour or two before I get a chance to post it. Storm, you will love that one, it has huge amounts of information in it and I will go get a screen capture of the slides that are a bit blury in my video to post up. Fascinating!

Wink

 

[WinkHPD]

Date: 4/25/2009 5:51:13 PM
Author: DiaGem
What was Peter''s last sentence in this video?
I had a hard time understanding although I replayed it a few times.

Thanks,

"The numbers are scientifically based, and they are going to be a real boone to this industry in the long run."

You''re welcome.

Wink