Diamond performance- Diamond viewing position

[oldminer]

Does the way a diamond is worn, such as the difference between mounting diamonds into earrings and mounting them into rings or mounting them into pendants have enough effect on their appearance due to the way they tend to gather light from different angles mean that earring diamonds may be cut for that purpose with different angles than diamonds destined to be set into rings?

Obvious to me is that earrings do not get the same head blockage angles as ring diamonds or pendant set diamonds. Also, lighting angles are very different for diamonds set vertically in earrings and pendant versus ring diamonds set horizontally. Can this account for some of the performance or appearance features that DiamCalc cannot yet mimic? Should diamond cutters consider cutting certain diamonds in speacial ways for earrings nd pendants?

 

[Serg]

Date: 1/25/2010 10:08:39 AM
Author:oldminer

Does the way a diamond is worn, such as the difference between mounting diamonds into earrings and mounting them into rings or mounting them into pendants have enough effect on their appearance due to the way they tend to gather light from different angles mean that earring diamonds may be cut for that purpose with different angles than diamonds destined to be set into rings?

Obvious to me is that earrings do not get the same head blockage angles as ring diamonds or pendant set diamonds. Also, lighting angles are very different for diamonds set vertically in earrings and pendant versus ring diamonds set horizontally. Can this account for some of the performance or appearance features that DiamCalc cannot yet mimic? Should diamond cutters consider cutting certain diamonds in speacial ways for earrings nd pendants?

Dave,
usually Floor has not primary light sources, so best pendant set diamondS have not to have more than one mirror symmetry ( Hypothesis ).

But many mirror symmetries are helpful for ring diamonds

 

[oldminer]

It seemed to me that some of the differences of opinion that you and Garry have may be due to the viewing position of the stones he tested as earrings versus the standard lighting model based on how rings are set in DiamCalc. I know you can vary the lighting and position, but possibly what Garry has observed would make sense with the special angles of viewing one uses with earrings versus the standard model. Garry and human observers give what they see, or what they think they see, and DiamCalc and optical science gives us the actual, although possibly not visible to us, results. Making these two distinctly different approaches agree with one another would seem impossible, but understanding of why they do not agree ought to be explainable. Human vision physiology limitations and human perception are not objective measures.

 

[Serg]

Date: 1/25/2010 11:24:37 AM
Author: oldminer
It seemed to me that some of the differences of opinion that you and Garry have may be due to the viewing position of the stones he tested as earrings versus the standard lighting model based on how rings are set in DiamCalc. I know you can vary the lighting and position, but possibly what Garry has observed would make sense with the special angles of viewing one uses with earrings versus the standard model. Garry and human observers give what they see, or what they think they see, and DiamCalc and optical science gives us the actual, although possibly not visible to us, results. Making these two distinctly different approaches agree with one another would seem impossible, but understanding of why they do not agree ought to be explainable. Human vision physiology limitations and human perception are not objective measures.

Dave,

Garry used Drena pendants as rings during tests . ( two similar diamonds are very helpful for such tests. I think it is main reason why Garry used pendants. Also Drena pendants are easy accessible
for Garry)

Sure It was not tests between pendants set diamonds and rings set diamonds .

 

[Mrs Mitchell]

Date: 1/25/2010 10:08:39 AM
Author:oldminer

Does the way a diamond is worn, such as the difference between mounting diamonds into earrings and mounting them into rings or mounting them into pendants have enough effect on their appearance due to the way they tend to gather light from different angles mean that earring diamonds may be cut for that purpose with different angles than diamonds destined to be set into rings?

Obvious to me is that earrings do not get the same head blockage angles as ring diamonds or pendant set diamonds. Also, lighting angles are very different for diamonds set vertically in earrings and pendant versus ring diamonds set horizontally. Can this account for some of the performance or appearance features that DiamCalc cannot yet mimic? Should diamond cutters consider cutting certain diamonds in speacial ways for earrings nd pendants?

oldminer, this is fascinating and I''m intrigued to see what all the experts think. Are you referring only to round brilliant diamonds, or is there merit in considering how one''s choice of other shapes could be influenced by intended purpose?

Thanks
Jen

 

[oldminer]

We always discuss diamonds being viewed face-up and almost always automatically assume we are speaking of diamonds mounted in rings so that lighting is evenly provided from above and our head blocks a certain angular amount of this lighting. However, in another thread, it was said that certain shallower or steeper stones set in earrings had a particularly good look and performance. I am asking those who know more to give their opinion if part of this effect might well be the different lighting such vertically mounted diamonds have with light vcoming mostly from one side and the head blocking a lot less of the light.

It seems as if Serg agrees, to an extent. DiamCalc can be configured to mimic lighting of most any type and angle, but we typically use the standard of a face-up with lighting from above. Can we make certain modified cuts which would be best as earrings? I''d be curious to know.

 

[Serg]

Date: 1/25/2010 3:05:24 PM
Author: oldminer
We always discuss diamonds being viewed face-up and almost always automatically assume we are speaking of diamonds mounted in rings so that lighting is evenly provided from above and our head blocks a certain angular amount of this lighting. However, in another thread, it was said that certain shallower or steeper stones set in earrings had a particularly good look and performance. I am asking those who know more to give their opinion if part of this effect might well be the different lighting such vertically mounted diamonds have with light vcoming mostly from one side and the head blocking a lot less of the light.


It seems as if Serg agrees, to an extent. DiamCalc can be configured to mimic lighting of most any type and angle, but we typically use the standard of a face-up with lighting from above. Can we make certain modified cuts which would be best as earrings? I''d be curious to know.

Dave,

reiamCalc can be configured to mimic lighting of most any type and angle, but we typically use the standard of a face-up with lighting from above.

to optimise cut for earrings you need use exact face-up position. But you need create Light schema from diamond point view in earrings. Just it.

re:t was said that certain shallower or steeper stones set in earrings had a particularly good look and performance

Garry statement is what only shallower diamonds are good for earrings. he did not recommended steeper diamonds for earrings.

In other thread I did not discuss about diamonds for earrings at all .

 

[Karl_K]

Date: 1/25/2010 3:05:24 PM
Author: oldminer
Can we make certain modified cuts which would be best as earrings? I'd be curious to know.

yes we can and I have.
DC can model it very well with some work.
I just wish DC pro could do tilt it would make it much easier.
I can not share models:
1> self promotion
2> I may want to market them someday.

What I will share for a pendant the best diamonds I have ever seen for it was OEC that had to much head shadow from a shallow pavilion in a ring, EC and asschers with high crowns
The larger chunks of light and the wide area light gathering ability of the high crowns blew RB's out of the water for a pendant.
I have my Octavia prototype set in a pendant and the med VF's and high crown rock my world :}

 

[Karl_K]

Here is what im working on.
This a modified ASET with the red changed to black.
This is like in a pendant with someone in a dark suit standing in front of the diamond.
This is a high crown shallow pavilion.
As you can see it it still drawing in a lot of light.

 

[Karl_K]

Here is a DC standard tolk
It is obvious which is going to be the brighter diamond.

 

[Karl_K]

and :}

 

[yssie]

...

 

[Garry H (Cut Nut)]

Wow - there are so many threads running - no time to sleep!

Carried over from https://www.pricescope.com/community/threads/is-the-internet-and-cut-grading-the-enemy-of-creativity-in-cutting.133907/page-6

Sergey contends that WhatMeWorry''s P41.3 C34.9 T57% should have more fire and not much difference in light return when seen with stereo vision.

I reduced the crown angle to 34.5 (T57%) for this DCPro run and extended it from 40.0 to 41.5.
Interestingly the peak is clearly at 40.9.

 

[Serg]

Date: 1/26/2010 5:10:08 AM
Author: Garry H (Cut Nut)
Wow - there are so many threads running - no time to sleep!


Carried over from https://www.pricescope.com/community/threads/is-the-internet-and-cut-grading-the-enemy-of-creativity-in-cutting.133907/page-6


Sergey contends that WhatMeWorry''s P41.3 C34.9 T57% should have more fire and not much difference in light return when seen with stereo vision.


I reduced the crown angle to 34.5 (T57%) for this DCPro run and extended it from 40.0 to 41.5.

Interestingly the peak is clearly at 40.9.

Garry,

1)If you believe in these metrics you need account Light return Stereo in your advices
2)I want remind you what DC has not "Fire stereo ". ETAS Fire and Fire are not same.
3) I advice you check also ETas Fire mono and Fire Detas
4) I want repeat my main statements:

IS images do not account Fire and Stereo. It is rejection tool for fast selection well known and reasonable good solution.
other good and may be even better combinations still possible even for RBC. Best combinations have difference in Balance between Brilliancy, Fire , Scintillation And Pattern .
different people could prefer different balance between these components of diamond Beauty. It is question about Taste.


I do not see any proof what P41.2Cr34.5 worse than P40.7Cr34.5
I know at least one solid reason why P41.2Cr34.5 COULD have better Fire than P40.7Cr34.5( and may be even better LR for Human stereo vision).

One proportions could be good for short ( 250-600mm) Observer distances , other for long ( more than 2m)
P41.2Cr34.5 Could be better solution than P40.7Cr34.5 for short distances and worse for long distances .

If you call I will explain this reason (You need work in DC during my explanations), then you can try explain it on PS( if you will agree)

 

[Garry H (Cut Nut)]

Date: 1/26/2010 3:11:05 PM
Author: Serg

Date: 1/26/2010 5:10:08 AM
Author: Garry H (Cut Nut)
Wow - there are so many threads running - no time to sleep!


Carried over from https://www.pricescope.com/community/threads/is-the-internet-and-cut-grading-the-enemy-of-creativity-in-cutting.133907/page-6


Sergey contends that WhatMeWorry''s P41.3 C34.9 T57% should have more fire and not much difference in light return when seen with stereo vision.


I reduced the crown angle to 34.5 (T57%) for this DCPro run and extended it from 40.0 to 41.5.

Interestingly the peak is clearly at 40.9.

Garry,

1)If you believe in these metrics you need account Light return Stereo in your advices
2)I want remind you what DC has not ''Fire stereo ''. ETAS Fire and Fire are not same.
3) I advice you check also ETas Fire mono and Fire Detas
4) I want repeat my main statements:

IS images do not account Fire and Stereo. It is rejection tool for fast selection well known and reasonable good solution.
other good and may be even better combinations still possible even for RBC. Best combinations have difference in Balance between Brilliancy, Fire , Scintillation And Pattern .
different people could prefer different balance between these components of diamond Beauty. It is question about Taste.


I do not see any proof what P41.2Cr34.5 worse than P40.7Cr34.5
I know at least one solid reason why P41.2Cr34.5 COULD have better Fire than P40.7Cr34.5( and may be even better LR for Human stereo vision).

One proportions could be good for short ( 250-600mm) Observer distances , other for long ( more than 2m)
P41.2Cr34.5 Could be better solution than P40.7Cr34.5 for short distances and worse for long distances .

If you call I will explain this reason (You need work in DC during my explanations), then you can try explain it on PS( if you will agree)

Between 4 and 7 hours from now Sergey?

 

[Garry H (Cut Nut)]

Date: 1/26/2010 5:52:18 PM
Author: Garry H (Cut Nut)

Date: 1/26/2010 3:11:05 PM
Author: Serg

Date: 1/26/2010 5:10:08 AM
Author: Garry H (Cut Nut)
Wow - there are so many threads running - no time to sleep!


Carried over from https://www.pricescope.com/community/threads/is-the-internet-and-cut-grading-the-enemy-of-creativity-in-cutting.133907/page-6


Sergey contends that WhatMeWorry''s P41.3 C34.9 T57% should have more fire and not much difference in light return when seen with stereo vision.


I reduced the crown angle to 34.5 (T57%) for this DCPro run and extended it from 40.0 to 41.5.

Interestingly the peak is clearly at 40.9.

Garry,

1)If you believe in these metrics you need account Light return Stereo in your advices
2)I want remind you what DC has not ''Fire stereo ''. ETAS Fire and Fire are not same.
3) I advice you check also ETas Fire mono and Fire Detas
4) I want repeat my main statements:

IS images do not account Fire and Stereo. It is rejection tool for fast selection well known and reasonable good solution.
other good and may be even better combinations still possible even for RBC. Best combinations have difference in Balance between Brilliancy, Fire , Scintillation And Pattern .
different people could prefer different balance between these components of diamond Beauty. It is question about Taste.


I do not see any proof what P41.2Cr34.5 worse than P40.7Cr34.5
I know at least one solid reason why P41.2Cr34.5 COULD have better Fire than P40.7Cr34.5( and may be even better LR for Human stereo vision).

One proportions could be good for short ( 250-600mm) Observer distances , other for long ( more than 2m)
P41.2Cr34.5 Could be better solution than P40.7Cr34.5 for short distances and worse for long distances .

If you call I will explain this reason (You need work in DC during my explanations), then you can try explain it on PS( if you will agree)

Between 4 and 7 hours from now Sergey?

Sergey explained his idea last night.
I need some time to think and present them.
(Have a lot on next 2 days)

 

[whatmeworry]

I know I''ve asked this in the past but never really gotten a good answer, so I''ll ask it again in light of this subject and Storm''s designs.

Do you think a diamond that is worn in earrings or in a pendant should have more Green than Red when viewed under ASET than if it were worn in a ring?

 

[Garry H (Cut Nut)]

Date: 1/27/2010 6:36:20 PM
Author: whatmeworry
I know I''ve asked this in the past but never really gotten a good answer, so I''ll ask it again in light of this subject and Storm''s designs.

Do you think a diamond that is worn in earrings or in a pendant should have more Green than Red when viewed under ASET than if it were worn in a ring?

I prefer more red and blue, and as little green as possible.
These stones also tend to have better light return from the edges so they look much larger (as well as having a larger spread)

 

[Gleam]

David, because earrings don't have the head obstruction issue, can you get away with less than ideally cut earrings and still get lots of sparkle and fire? How "low" would you go for cut? Down to a GIA "good?"

 

[yssie]

Just my opinion:


Earrings - I think you want more direct light return for earrings because most women have hair that will block indirect light when worn down, and then there''s the small matter of having a face block indirect light from that direction

Pendant - I''d go with a stone that gathers more indirect light because you''re likely to be talking to people, shaking hands, hugging... people in front of you.

 

[whatmeworry]

Date: 1/27/2010 7:04:22 PM
Author: Garry H (Cut Nut)

Date: 1/27/2010 6:36:20 PM
Author: whatmeworry
I know I''ve asked this in the past but never really gotten a good answer, so I''ll ask it again in light of this subject and Storm''s designs.

Do you think a diamond that is worn in earrings or in a pendant should have more Green than Red when viewed under ASET than if it were worn in a ring?

I prefer more red and blue, and as little green as possible.
These stones also tend to have better light return from the edges so they look much larger (as well as having a larger spread)

Why would they have better light return? Aren''t the strongest light sources (overhead lights) now coming from the green part of the hemisphere in a pendant?

 

[Karl_K]

Date: 1/27/2010 6:36:20 PM
Author: whatmeworry
I know I''ve asked this in the past but never really gotten a good answer, so I''ll ask it again in light of this subject and Storm''s designs.

Do you think a diamond that is worn in earrings or in a pendant should have more Green than Red when viewed under ASET than if it were worn in a ring?

no, but they should be able to draw secondary light from the green zone in a good manner.

 

[Karl_K]

Date: 1/27/2010 7:06:36 PM
Author: Gleam
David, because earrings don't have the head obstruction issue, can you get away with less than ideally cut earrings and still get lots of sparkle and fire? How 'low' would you go for cut? Down to a GIA 'good?'

no it is not that easy.
diamonds get a good cut grade mostly because of leakage not obstruction.
There are several combos in the gia VG range however that would be excellent in earrings if someone was actually cutting them.