Virtual Facets and patterns, a Discussion about step cuts.

[strmrdr]

Date: 9/2/2008 2:16:20 PM
Author: Serg

Re: The larger the virtual facets the larger the flashes coming from the diamond will be, but it also takes more movement to make them flash on and off.

Karl,


It is Misleading statement.

Do you mean diamond with big virtual facets or one big virtual facet needs bigger movement to catch light source?


Bigger virtual facet could catch light source faster than small virtual facets ( one big facet will catch one source light more often than one small virtual facet. But diamond with big virtual facets could catch light source much more rare than Princess cut)

Two virtual facets with same size could collect light source with quite different probability. It depends from angular speed.

Virtual facets what create head obscuration have usually low angular speed( could be even zero)

Angular speed( DETAS) and Size are both important to catch light

Yes I am aware of angular spread.
Where it is gathering the light is not relevant to what I am talking about.
The size of the returned light beam and the separation between them is.
It takes more movement to move a large beam over the eye going from on to off and it requires more movement to cover the separation.
One diamond could have 200 large flashes and another 50 small flashes and it would still hold true that the larger flashes and larger separation take more movement to go from on to off.

 

[strmrdr]

Date: 9/2/2008 7:52:13 AM
Author: Garry H (Cut Nut)

This is a weakness in your approach. Without specific methods to know the size of virtual window that can be seen, you can not know anything about virtual facets.

Like I said that is to complicated for an easy to understand article.
There is also disagreement on what that size is as people can distinguish flashes well below the level of detail they can pick up.
To prove that all I have to do is take my glasses off.
The entire monitor is one big blur and looks like a greyish blur.
Yet a flashing icon, in this case this

and this one

is readily apparent that it is flashing while this one is not

.
So without my glasses I cant read even Marty text nor tell it is there yet I can see flashes below this level

and this

but not this

.
I would take 10 years to explain that in an article.

 

[strmrdr]

Date: 9/2/2008 2:06:59 PM
Author: Serg
Karl,


re:When comparing diamonds of the same size, larger virtual facets - because they have more light gathering area - will produce more flash in soft and low light than diamonds with smaller virtual facets.


Why?

for example in Hemisphere light cut with big facets has not any advantages or disadvantages

Cut with big number virtual facets could have advantages in light with spot light sources . via versa is not correct.

Take the default Emerald cut in DC change the width to 6mm and set the lighting to ISO without head.
Record a movie in figure 8 10 degrees 10 degrees, you get flashes and even large fire from the large virtual facets.
Now take the default princess cut and do the same and it shimmers more than flashes.
Now do the same thing with 1 degree and 1 degree.
The princess still shimmers and the SEC now shimmers like the princess cut under the crown steps but the center is basically dead.

 

[diagem]

Date: 9/2/2008 2:02:56 PM
Author: Serg

Date: 9/2/2008 3:42:25 AM
Author: Paul-Antwerp

Date: 9/1/2008 4:47:46 PM
Author: strmrdr
Here is the ASET white.
Do you think I should switch to the ASET white?

That is up to you. I just found the current pic confusing, since what is leakage in the IS was green in the ASET.

Paul,Karl

it is very typical. One virtual facet could collect light from different directions.

=

"Re> Serg,

"BTW.
One virtual facets could has strong leakage and have bright green color in ASET in same time"



Serg..., do you mean that a virtual facet can show leakage that is actually reflecting from a facet which is in a different location within the Diamond??
Thats why the ASET will interpret the color of the actual facet and not consider the virtual facet?

 

[strmrdr]

Here is DETAS for the default tolk the first image is 80.5%lgf and smaller virtual facets the second is 65% which has much larger virtual facets.
Notice the larger lines and more black spaces in the image on the right with the larger virtual facets.
If you moved this image in front of your face it would require more movement of the one on the right for the same number of flashes to be seen.

 

[Serg]

Date: 9/2/2008 3:42:10 PM
Author: DiaGem

Date: 9/2/2008 2:02:56 PM
Author: Serg

Date: 9/2/2008 3:42:25 AM
Author: Paul-Antwerp

Date: 9/1/2008 4:47:46 PM
Author: strmrdr
Here is the ASET white.
Do you think I should switch to the ASET white?

That is up to you. I just found the current pic confusing, since what is leakage in the IS was green in the ASET.

Paul,Karl


it is very typical. One virtual facet could collect light from different directions.

=

''Re> Serg,

''BTW.
One virtual facets could has strong leakage and have bright green color in ASET in same time''




Serg..., do you mean that a virtual facet can show leakage that is actually reflecting from a facet which is in a different location within the Diamond??
Thats why the ASET will interpret the color of the actual facet and not consider the virtual facet?

Diagem, See sample

 

[Serg]

Are my statements clear now?

 

[strmrdr]

Date: 9/2/2008 7:52:13 AM
Author: Garry H (Cut Nut)


All your modelling is done with a double reflection in DiamCalc. That is based on a DC setting of ''double'', there is no option for triple, quadruple etc. You can model many times more reflections in diamcalc, and the larger the stone, the more of them are able to be discerned.


If you play inside DiamCalc you will find that even up to 10 patern calculations you will see many more extra facets.

Garry for 8 weeks I had a 12mm CZ RB here, (wifey2b has it with her now) and the patterns lined up with the double reflection in DC.
I used it to guesstimate the crown and pavilion angles so spent a lot of time comparing them in regular lighting, in ASET and in IS.
I would have noticed if I was getting triple and quadruple reflections.
While I''m not saying it cant happen it didn''t happen at 12mm.

 

[diagem]

Same facet = reflect + leak ....???

 

[Serg]

Date: 9/2/2008 4:23:07 PM
Author: DiaGem
Same facet = reflect + leak ....???

Yes. Why are not?
it was first statement
Please see second too.
Second is much more important for ASET technology

 

[diagem]

Date: 9/2/2008 4:46:01 PM
Author: Serg

Date: 9/2/2008 4:23:07 PM
Author: DiaGem
Same facet = reflect + leak ....???

Yes. Why are not?
it was first statement
Please see second too.
Second is much more important for ASET technology

So, can virtual facets even be researched?
Can there be a straight answer/proof since Diamonds need light & movement to live or show beauty?

Is precision symmetry even an issue to consider in virtual facet research?

Isn''t asymmetry the potential upside of virtual facets.

I read this thread and everyone is making sense....

.

oooops...

 

[strmrdr]

Date: 9/2/2008 5:00:39 PM
Author: DiaGem

Date: 9/2/2008 4:46:01 PM

Author: Serg

Date: 9/2/2008 4:23:07 PM

Author: DiaGem

Same facet = reflect + leak ....???

Yes. Why are not?

it was first statement

Please see second too.

Second is much more important for ASET technology

So, can virtual facets even be researched? It is a tough subject that hasnt been settled I knew I was opening a can of worms when I went beyond them just forming patterns.
That part can not be disputed.

Can there be a straight answer/proof since Diamonds need light & movement to live or show beauty? it would be a lot easier in person which is why I verified my findings with real diamonds and CZ''s as much as I could


Is precision symmetry even an issue to consider in virtual facet research? very much so


Isn''t asymmetry the potential upside of virtual facets. if you cut a large diamond with to few virtual facets non-symmetrical cutting can add virtual facets and break them up compared to a symmetrical stone.


I read this thread and everyone is making sense....

. lol


oooops...

Just to keep the post count down remember when we discussed the reddish black zones in the IS image in the article?
They are showing a combination of return and obstruction under the IS.
Virtual facets can also leak and return light also.
I classified both as partial return.

 

[Paul-Antwerp]

Date: 9/2/2008 4:04:36 AM
Author: strmrdr

Date: 9/2/2008 3:42:25 AM
Author: Paul-Antwerp

Date: 9/1/2008 4:47:46 PM

Author: strmrdr

Here is the ASET white.

Do you think I should switch to the ASET white?

That is up to you. I just found the current pic confusing, since what is leakage in the IS was green in the ASET.

Thanks Paul if its confusing it needs to be changed.

I would not change the pic. I would point to a virtual facet where leakage is black in the ASET, just to keep things clear.

 

[Paul-Antwerp]

Date: 9/2/2008 2:55:27 PM
Author: strmrdr

Date: 9/2/2008 2:16:20 PM
Author: Serg

Re: The larger the virtual facets the larger the flashes coming from the diamond will be, but it also takes more movement to make them flash on and off.

Karl,

It is Misleading statement.

Do you mean diamond with big virtual facets or one big virtual facet needs bigger movement to catch light source?

Bigger virtual facet could catch light source faster than small virtual facets ( one big facet will catch one source light more often than one small virtual facet. But diamond with big virtual facets could catch light source much more rare than Princess cut)

Two virtual facets with same size could collect light source with quite different probability. It depends from angular speed.

Virtual facets what create head obscuration have usually low angular speed( could be even zero)

Angular speed( DETAS) and Size are both important to catch light

Yes I am aware of angular spread.
Where it is gathering the light is not relevant to what I am talking about.
The size of the returned light beam and the separation between them is.
It takes more movement to move a large beam over the eye going from on to off and it requires more movement to cover the separation.
One diamond could have 200 large flashes and another 50 small flashes and it would still hold true that the larger flashes and larger separation take more movement to go from on to off.

I cannot understand how the origin of the light cannot be relevant. It is, in my book, the essence of gemmology: ''In the beginning, there was light''.

 

[strmrdr]

Date: 9/3/2008 9:09:08 AM
Author: Paul-Antwerp

I cannot understand how the origin of the light cannot be relevant. It is, in my book, the essence of gemmology: 'In the beginning, there was light'.

Where its drawing light is great for theoretical work but what people see is the outgoing light.
Its the same reason AGS uses outgoing light to evaluate scintillation events.

https://www.pricescope.com/community/threads/agsl-scintillation-studies.63707/

Look at the structured light environment pictures.
Not only are the flashes larger the separation between them is also larger in the OEC.
That is the 3rd proof, the first is the videos the second DETAS above the 3rd is the scintillation maps.
With large virtual facets the size of the flash and the separation increase in real world lighting.
You will notice on the AGS pictures that the theoretical large event map is different than shown in the structured light environment for the OEC.
One is showing potential events the other actual.
As the diamond is tilted the area in the large event map will show flashes but not all at the same time.

 

[Serg]

Date: 9/3/2008 11:21:20 AM
Author: strmrdr

Date: 9/3/2008 9:09:08 AM
Author: Paul-Antwerp

I cannot understand how the origin of the light cannot be relevant. It is, in my book, the essence of gemmology: ''In the beginning, there was light''.

Where its drawing light is great for theoretical work but what people see is the outgoing light.
Its the same reason AGS uses outgoing light to evaluate scintillation events.

https://www.pricescope.com/community/threads/agsl-scintillation-studies.63707/

Reading that thread I have learned a lot since then.

Re:Its the same reason AGS uses outgoing light to evaluate scintillation events.

Strmdr,

Sorry, but AGS R&D use wrong method for evaluate scintillation. Completely wrong method. They account only "longitude movement". ASET has cycle symmetry.
There are other critical mistake in ASG Scintillation method


"..
From private exchange with Sergey.
Sergey sees the main problem of the AGSL approach to the scintillation grading is the use of ASET structured illumination.

If one takes reflections of the virtual facets on a sphere (ETAS), then it becomes apparent that facets moved within ASET zones won’t produce scintillations. Only those facets, which reflections often crossing boundary between red and green zones, contribute to scintillation in AGSL model.

In particular, a diamond with reflections along zones’ boundaries will have maximum scintillation, which is nonsense.

It is important for the facets reflections to move with maximum angular pace and direction is absolutely irrelevant. AGSL, however, doesn’t count movement in horizontal direction, while in vertical direction AGS counts only reflection crossing the abstract ASET zone borders. There is also no account of the reflection length… - Generally speaking: clear underdevelopment.

Hypothetical maximum of scintillation in this model could be reached when all the reflections are located along the zone boundary and jump back ad forth. If one can manage to cut a diamond in such manner, it would have no scintillation because probability of the light source position along the zone border is minimal while in other areas such diamond won’t reflect at all.

In reality, scintillation is high if facets’ reflections are distributed equally and move actively.

 

[strmrdr]

Date: 9/3/2008 11:46:41 AM
Author: Serg


In reality, scintillation is high if facets’ reflections are distributed equally and move actively.

Which is what I have been saying.
Small virtual facets producing small flashes with small separation will have more visible flashes per a given amount of movement.
They are distributed more equally as the space between them is smaller and they are more active because there is more of them in any given space.
This is easy to demo in person, cut or find a RB and a double RB with the same size and c/p angles then compare them.
This would be an interesting combo to add to the master stone study.

edit: this is only true as long as the light is strong enough for the small virtual facets to actually return light.
They will stop returning visible flashes before the large virtual facets will as the light is reduced.

 

[Serg]

Date: 9/3/2008 12:00:12 PM
Author: strmrdr

Date: 9/3/2008 11:46:41 AM
Author: Serg


In reality, scintillation is high if facets’ reflections are distributed equally and move actively.

Which is what I have been saying.
Small virtual facets producing small flashes with small separation will have more visible flashes per a given amount of movement.
They are distributed more equally as the space between them is smaller and they are more active because there is more of them in any given space.
This is easy to demo in person, cut or find a RB and a double RB with the same size and c/p angles then compare them.
This would be an interesting combo to add to the master stone study.

edit: this is only true as long as the light is strong enough for the small virtual facets to actually return light.
They will stop returning visible flashes before the large virtual facets will as the light is reduced.

Strmdr,
"Facets reflections"(ETAS) distribution could be quite different Virtual facets distribution
Diamonds with a lot of virtual facets could have very poor Scintillation, just because angular speed is low and ETAS distribution is bad

 

[strmrdr]

Date: 9/3/2008 2:01:32 PM
Author: Serg

Strmdr,

''Facets reflections''(ETAS) distribution could be quite different Virtual facets distribution

Diamonds with a lot of virtual facets could have very poor Scintillation, just because angular speed is low and ETAS distribution is bad

understood.
VF size can not make up for bad angles.
But the problem is explaining it and making it simple.

 

[Garry H (Cut Nut)]

Date: 9/3/2008 5:01:05 PM
Author: strmrdr

Date: 9/3/2008 2:01:32 PM
Author: Serg


Strmdr,

''Facets reflections''(ETAS) distribution could be quite different Virtual facets distribution


Diamonds with a lot of virtual facets could have very poor Scintillation, just because angular speed is low and ETAS distribution is bad

understood.
VF size can not make up for bad angles.
But the problem is explaining it and making it simple.

You have a worthy goal Karl.

But you place yourself and your reputation at risk if the simplification is inaccurate.

Simple can be stupid, or it can make complex things simple. The later is not easy.

 

[strmrdr]

Date: 9/4/2008 7:33:56 AM
Author: Garry H (Cut Nut)

You have a worthy goal Karl.


But you place yourself and your reputation at risk if the simplification is inaccurate.


Simple can be stupid, or it can make complex things simple. The later is not easy.

In the specific conditions with step cuts presented in the article I stand by it 100%.
The large and small VF's in steps cuts do act as I described in relation to one another.
2 min looking at an EC will verify it which I have done.
On the ends where the small VFs are you get fast flashes that flash very rapidly on/off with small movement where it takes more movement to get the large VFs to flash on and off.
The large VFs flash in lower light than the small VFs.
What I am working on now is how to reword it and to get the videos to work for everyone.

 

[strmrdr]

This is a large image but the detail is too hard to see when it was made smaller.
The end zones of this DETAS image are separated out by the red lines from the center for an EC.
There is a clear separation in size.