Fire Performance Scope and other questions

[pricescope]

I''m moving here Adamasgem'' Q&A.

 

[goodpointz]

I have been trying to follow Marty''s work with Eightstar and the Fire Performance Scope for a while now, and have been disappointed that there hasn''t been more (apparent) interest or discussion. I''ve also been very excited to see how Dave''s ImaGem technology plays out. Some of the discussions often get too technical for me despite Garry''s efforts, but I certainly prefer them to this type of banter.

That being said, while some of you in the industry either know Marty or have worked with him enough to make a personal judgement that he is above any bias, it shouldn''t be hard to understand why an external observer can''t automatically make the same assumption. To be fair, Marty was not originally forthcoming about his past association with Eightstar- this was brought to light by Garry in yet another controversial thread- and he made no mention of the fact that he was (seemingly) solicited by an Eightstar dealer to rekindle this two and a half year old thread. These are not accusations; but I do understand where some consumers are coming from. My personal take is that regardless of any potential bias, Marty is clearly very smart and expert, and so I take great interest in what he has to say. In any case, these types of flame wars never prove useful. Hopefully the meaningful discussion can get back on track, and in that spirit, I had a few more questions about the Fire Performance Scope for Marty:

. While it is easy to see that the right-most diamond is a dud, the 2nd from the right seems to have just as much color (if not more) that the left-most diamond. You mentioned in the previous thread that pure spectral hues were best; I don''t see much of that in any of the images minus the blue arrow tips of the Eightstar, and some small red areas in the three ideal cuts. Everything else looks pretty much pastel to me- is it these blue arrow tips that are the distinguishing factor?

. There is much more black in the Eightstar image, wherease the branded ideal appears to have color throughout. Is this black a positive feature or is it somehow balanced by the pure blue hues? It does seem to provide some contrast in helping the arrows pattern to stand out more; is this significant? Essentially, to my untrained eyes, the image 2nd from the right looks just as good (if not better) than the leftmost one, and I was wondering what makes it potentially inferior, both in terms of the scope image, and how the actual diamond looked to your naked eyes.

. Finally, does this new Fire Performance Scope provides some means of absolute ranking/evaluation, or is it much like the other technologies (i.e. FireScope/IdealScope/BrillianceScope), where through experience, you''ve correlated certain images or patterns under the scope with particular cuts that perform best to your naked eyes, and visa versa?

Perhaps it is impossible to develop an objective method of scoring diamond beauty, which may intrinsicially be a subjective evaluation as many have claimed, but I remain curious. Thanks in advance!

 

[Midnight]

Goodpointz:
"Finally, does this new Fire Performance Scope provides some means of absolute ranking/evaluation, or is it much like the other technologies (i.e. FireScope/IdealScope/BrillianceScope), where through experience, you''ve correlated certain images or patterns under the scope with particular cuts that perform best to your naked eyes, and visa versa?"


Marty:

In addition to what Goodpointz had mentioned in regards to comparing the Fire Performance Scope to the Firescope/Idealscope/BrillianceScope....I would be curious to hear your opinion on what the Isee2 and ASET purported to reveal in terms of optical performance.

 

[adamasgem]

Date: 5/31/2005 2:15:20 PM
Author: goodpointz

I have been trying to follow Marty''s work with Eightstar and the Fire Performance Scope for a while now, and have been disappointed that there hasn''t been more (apparent) interest or discussion. I''ve also been very excited to see how Dave''s ImaGem technology plays out. Some of the discussions often get too technical for me despite Garry''s efforts, but I certainly prefer them to this type of banter.

That being said, while some of you in the industry either know Marty or have worked with him enough to make a personal judgement that he is above any bias, it shouldn''t be hard to understand why an external observer can''t automatically make the same assumption. To be fair, Marty was not originally forthcoming about his past association with Eightstar- this was brought to light by Garry in yet another controversial thread- and he made no mention of the fact that he was (seemingly) solicited by an Eightstar dealer to rekindle this two and a half year old thread. These are not accusations; but I do understand where some consumers are coming from. My personal take is that regardless of any potential bias, Marty is clearly very smart and expert, and so I take great interest in what he has to say. In any case, these types of flame wars never prove useful. Hopefully the meaningful discussion can get back on track, and in that spirit, I had a few more questions about the Fire Performance Scope for Marty:

. While it is easy to see that the right-most diamond is a dud, the 2nd from the right seems to have just as much color (if not more) that the left-most diamond. You mentioned in the previous thread that pure spectral hues were best; I don''t see much of that in any of the images minus the blue arrow tips of the Eightstar, and some small red areas in the three ideal cuts. Everything else looks pretty much pastel to me- is it these blue arrow tips that are the distinguishing factor?

Yup, you are correct there, that stone is a very nice GIA ex, ex, But I caution that doesn''t mean ithat all GIA ex,ex will render good fire performance, in the prototype device I built. It is a complex issue, regarding optical symmetry and nearly "ideal" balanced crown pavillion angles. Any misalignment or miscutting seems to render the imaging more pastel in color tending toward the earth tones and "muddy" fire as the cutting quality deminishes, an internal color mixing, I believe. In the stones I had run through initially, there was a general direct correlation between AGS cut grade and Fire Performance, with some exceptions mostly, if not always, seemingly due to a lower cut grade because of girdle thickness.

. There is much more black in the Eightstar image, wherease the branded ideal appears to have color throughout. Is this black a positive feature or is it somehow balanced by the pure blue hues? It does seem to provide some contrast in helping the arrows pattern to stand out more; is this significant? Essentially, to my untrained eyes, the image 2nd from the right looks just as good (if not better) than the leftmost one, and I was wondering what makes it potentially inferior, both in terms of the scope image, and how the actual diamond looked to your naked eyes.

Each stone cut by any cutter will be slightly different in "Fire Performance Imaging", per se. The images presented are the resulting from over 5000 point sources of white light, and as a stone is rotated ever so slightly, one facet might light up an entirely different color. These are representative images. As to "blackness" you comment on, there is an absense of extremely high angle lighting, due to the camera setup, and each stone has its own characteristics regarding this "snapshot" of Fire. What I have found is that visual purity of color improves with cutting quality.

. Finally, does this new Fire Performance Scope provides some means of absolute ranking/evaluation, or is it much like the other technologies (i.e. FireScope/IdealScope/BrillianceScope), where through experience, you''ve correlated certain images or patterns under the scope with particular cuts that perform best to your naked eyes, and visa versa?

I haven''t had the time or funding to create a "scale" so to speak, I have data on a good many stones, and it certainly easily weeds out the good from the bad. Technically, I am looking at ways of automatically ranking the performance images, but haven''t spen much time at that lately. Got to pay the bills first. I have made a presentation of these visual correlations over a year ago to EightStar dealers, which may become publically available in the future, after the patent application has run its course.


Perhaps it is impossible to develop an objective method of scoring diamond beauty, which may intrinsicially be a subjective evaluation as many have claimed, but I remain curious. Thanks in advance!

I think a picture is worth a thousand words, a diamond is what it is. A really objective numerical "scale" is a ways off. Right now the pics tell the story, you either like them or you don''t. One thing I would say is that the less pure the spectral hue, it becomes readily apparent that the "Fire" one sees as emenating from such a diamond is deminished. The brodflash" fire, of a stone cut with EightStar''s quality of optical symmetry (and others are trying to emulate their superior cutting, and some have come very close), is much more noticeable from a distance, the colors catch the eye easier from a distance, they are bigger flashes of spectral hues than even a slightlly off make stone, and don''t get lost as one moves away from the stone.

I believe that what a consumer would want, is that their diamond catches the eye of others. It is one thing to look at a stone from 14 or 18 inches away, and it is another when one can "see" that particular stone from across the dinner table or from across the room, regardless of the size of the stone. Some stones have it, most don''t.

You certainly can''t evaluate Fire in typical jewelry store lighting, as the glare of the typically intense lighting of a mall chain store, hides the fire of any stone. Differentiation of quality is next to impossible for the consumer in that situation, but that may be intentional by some.

I hope I have answered your questions, got to pack for Vegas now

 

[goodpointz]

Hi Marty, thanks for all the new info- very cool. A few more questions when you get a chance- sounds like you''ll be busy at the conference:

. The point you made about diamond beauty from a distance versus from up close is particularly interesting. Is there a trade-off between the two? In other words, would a diamond cut so that it produced fire that was eye-catching from a distance, by default also outperform other diamonds when viewed up close (14-18 in)? Or could a diamond that isn''t as fiery from a distance potentially look better up close than an Eightstar?

. The blackness I was talking about is primarily seen in the leftmost image and rightmost image (in the original set of four). In the Eightstar, the triangle pairs between the arrow tips (in the star facets), and the adjacent girdle wedges (at the perimeter) appear black or dark. In the rightmost image, there are also many clusters of dark triangles in the center/table area. Also, in the press release graphic (with five diamonds), there appears to be a great deal of black in the right three diamonds as well as some in the leftmost diamond (the Eightstar?); the exception seems to be the stone 2nd from the left, showing mostly just color. Do these represent a positive or negative feature, or is there some other more sophisticated interpretation?

. You''ve mentioned that well-cut diamonds with weaker optical symmetry show a muddying of color (earth tones, pastels); I take this to mean the colors as seen under the Fire Performance Scope. How does this translate into naked eyes viewing, e.g. do they actually display pastel/fainter colors, fewer flashes of fire, smaller flashes or fire, less intense flashes of fire, or brilliance instead of fire, (i.e. does unresolved color mean it is then perceived as white light reflection?). Specifically, for example, the diamond 2nd from the right (the branded ideal)- when viewed with your naked eyes, can you describe how its appearance or performance was distinct or inferior to the Eightstar?

Thanks in advance, and glad to see the discussion back on track.

 

[pricescope]

I''m sorry, guys, but we cannot post here press releases, which can be interpreted as promotional materials.

I ask Adamasgem to post educational materials when they will be available for open publications...

 

[adamasgem]

I took considerable time to post two sets of pictures, AND MAKE COMMENTARY
1) THE 4 PICTURES being discussed above
2) A lengthly commentary on how I wanted to conduct this thread along with a published press release from April 2004 announcing the Fire Performance Scope development, that happened to have been published by EightStar, one of PriceScopes paid advertizers, I might add. It outlined my involvement at the time with EightStar and and I had considerable commentary about well cut diamonds. I would hope that Leonid would have the courtesy to repost my commentarys and JUST delete the press release if he feels it is "offensive", as I don''t have copies of my posts.

 

[adamasgem]

Date: 6/1/2005 12:20:23 PM
Author: goodpointz

Hi Marty, thanks for all the new info- very cool. A few more questions when you get a chance- sounds like you''ll be busy at the conference:

. The point you made about diamond beauty from a distance versus from up close is particularly interesting. Is there a trade-off between the two? In other words, would a diamond cut so that it produced fire that was eye-catching from a distance, by default also outperform other diamonds when viewed up close (14-18 in)? Or could a diamond that isn''t as fiery from a distance potentially look better up close than an Eightstar?

I point is, from what I have seen, that diamonds that may "perform" up close, who don''t exhibit braodflash fire, don''t perform well at a distance, the dispersed light gets lost. A classic example is the dime store opal, which looks good up close, and then becomes pure white when you move away from it. It has to do with the resolvability of the fire with thw human eye. Large object can be identified from a greater distance

. The blackness I was talking about is primarily seen in the leftmost image and rightmost image (in the original set of four). In the Eightstar, the triangle pairs between the arrow tips (in the star facets), and the adjacent girdle wedges (at the perimeter) appear black or dark. In the rightmost image, there are also many clusters of dark triangles in the center/table area. Also, in the press release graphic (with five diamonds), there appears to be a great deal of black in the right three diamonds as well as some in the leftmost diamond (the Eightstar?); the exception seems to be the stone 2nd from the left, showing mostly just color. Do these represent a positive or negative feature, or is there some other more sophisticated interpretation?

Since leonid removed the post with the four pictures I will refrain from further comment until HE restores my post so we can talk intelligently about it without having to refer to another thread.

. You''ve mentioned that well-cut diamonds with weaker optical symmetry show a muddying of color (earth tones, pastels); I take this to mean the colors as seen under the Fire Performance Scope. How does this translate into naked eyes viewing, e.g. do they actually display pastel/fainter colors, fewer flashes of fire, smaller flashes or fire, less intense flashes of fire, or brilliance instead of fire, (i.e. does unresolved color mean it is then perceived as white light reflection?). Specifically, for example, the diamond 2nd from the right (the branded ideal)- when viewed with your naked eyes, can you describe how its appearance or performance was distinct or inferior to the Eightstar?

I can''t answer that question directly, I have white light going in, and the pastels and earth tones result from a mixing of colors, what you would see it what is coming out of the diamond mixed with the ambient light, which varies. Physically, ALL colors emanating from a diamond will mix with the ambient light, and if they are already mixed, they will loose resolvability sooner.

Thanks in advance, and glad to see the discussion back on track.

 

[adamasgem]

Date: 5/31/2005 2:48:38 PM
Author: Midnight
Goodpointz:
''Finally, does this new Fire Performance Scope provides some means of absolute ranking/evaluation, or is it much like the other technologies (i.e. FireScope/IdealScope/BrillianceScope), where through experience, you''ve correlated certain images or patterns under the scope with particular cuts that perform best to your naked eyes, and visa versa?''


Marty:

In addition to what Goodpointz had mentioned in regards to comparing the Fire Performance Scope to the Firescope/Idealscope/BrillianceScope....I would be curious to hear your opinion on what the Isee2 and ASET purported to reveal in terms of optical performance.

I had taken considerable time to reply to your post and also included this picture, but it appears that it was pulled (maybe inadvertently), and I getting on a plane to Vegas in a couple of hours, and will have a little discussion with Leonid on this. I would always take the time to edit any post of mine if the powers to be would have the courtesy to ask me, instead of just yanking posts without sending a copy of the "offending" post.

 

[Midnight]

Date: 6/1/2005 1:52:09 PM
Author: adamasgem

Date: 5/31/2005 2:48:38 PM
Author: Midnight
Goodpointz:
''Finally, does this new Fire Performance Scope provides some means of absolute ranking/evaluation, or is it much like the other technologies (i.e. FireScope/IdealScope/BrillianceScope), where through experience, you''ve correlated certain images or patterns under the scope with particular cuts that perform best to your naked eyes, and visa versa?''


Marty:

In addition to what Goodpointz had mentioned in regards to comparing the Fire Performance Scope to the Firescope/Idealscope/BrillianceScope....I would be curious to hear your opinion on what the Isee2 and ASET purported to reveal in terms of optical performance.

I had taken considerable time to reply to your post and also included this picture, but it appears that it was pulled (maybe inadvertently), and I getting on a plane to Vegas in a couple of hours, and will have a little discussion with Leonid on this. I would always take the time to edit any post of mine if the powers to be would have the courtesy to ask me, instead of just yanking posts without sending a copy of the ''offending'' post.

Marty:

Thank you for your educational effort! Hopefully this can be resolved and the "edited" version be reposted.

 

[Garry H (Cut Nut)]

1. Old cut diamonds show bigger across the room flashes of color, so therefore they are better?

2. I have an ongoing debate (good natured) with many people about whether diamonds should look good at 10 inches or less - (I am for 14 inches). Now we must grade fire from across the room?

3. No Fire I ever saw in any colorless gem was ''muddy'' - never

4. what is better - fewer bigger flashes or more small flashes (assuming the same "fire output")

 

[valeria101]

Date: 6/2/2005 1:26:40 AM
Author: Garry H (Cut Nut)


2. I have an ongoing debate (good natured) with many people about whether diamonds should look good at 10 inches or less - (I am for 14 inches). Now we must grade fire from across the room?

Do these guys wear diamonds where they can see them ?

I can''t imagine what use of diamonds brings them closer than 10 in to the eye of the beholder for more than an occasional instance... Any ideas ? Surely I would not have asked something like this if there wasn''t a respectable amount of biometrics mentioned around here already.

 

[RockDoc]

Date: 6/2/2005 2:13:13 AM
Author: valeria101

Date: 6/2/2005 1:26:40 AM
Author: Garry H (Cut Nut)


2. I have an ongoing debate (good natured) with many people about whether diamonds should look good at 10 inches or less - (I am for 14 inches). Now we must grade fire from across the room?

Do these guys wear diamonds where they can see them ?

I can''t imagine what use of diamonds brings them closer than 10 in to the eye of the beholder for more than an occasional instance... Any ideas ? Surely I would not have asked something like this if there wasn''t a respectable amount of biometrics mentioned around here already.

I think a lot of guys wear diamond rings. But maybe I''m wrong but I think women generally try to display their sparkly pet rocks ( as well as clothes, hats etc.) while men generally tend to "hide" any beautiful pet rocks they might be wearing in public.

But men''s diamond rings are gaining in popularity, so maybe that will change.

Rockdoc

 

[Garry H (Cut Nut)]

Roc I think Ana means guys = people.
You might like to read the entire thread and make some comments?

 

[valeria101]

Date: 6/4/2005 2:55:24 AM
Author: Garry H (Cut Nut)

Roc I think Ana means guys = people.

Right. Sorry for the confusion...

About the 10 inches... well, I did try to see how would one hold his/her hand to see a ring (or bracelet) at that distance and it is very awkward. Same goes for seeing a piece of jewelry on someone else - the 10 inch distance means getting close and personal. Seeing yourself in a mirror comes near, but still - 10 inch is too close.

This bit of "introspection" made me curious about where the 10 inch proposition ever came from ? Perhaps someone who does not wear jewelry but works on it ?

To me, translating habits and impressions into numbers feels rather "forced" (= artificial...counterintuitive) most of the time. For example, it took a while to get used to working with social indicators and acquire a certain way of thinking about their "approximate" nature. I would have never, never thought to make up an indicator to describe the habit of wearing jewelry! It even sounds funny

If anyone has a use for the numbers... it is as serious as any, of course.

 

[Garry H (Cut Nut)]

According to the AGS it is a US military standard that close inspection be carried out at 25cm which is a shade under 10 inches (? 9.85 ?).
And apparently it is the distance that an optomertist uses to set your glasses to during a consultation.

 

[JohnQuixote]

According to visual specialists, that is also a practical distance of accomodation (clear near focus) for all. Young''uns can focus clearly as close as 7cm. By age 45 accomodative ability drops to 25cm.

So, while close-in, it is not too close to disrupt accomodation in most of us.

 

[adamasgem]

Date: 6/2/2005 1:26:40 AM
Author: Garry H (Cut Nut)
1. Old cut diamonds show bigger across the room flashes of color, so therefore they are better?
As to the ability to generate observable Fire, they may be

2. I have an ongoing debate (good natured) with many people about whether diamonds should look good at 10 inches or less - (I am for 14 inches). Now we must grade fire from across the room?

Gary, you like to try to twist things around don''t you, I didn''t say that. I said that it appears that in stones that generate broader areas of Fire, and pure spectral hues, the Fire is more observable at greater distances
3. No Fire I ever saw in any colorless gem was ''muddy'' - never

I suggest you might need new glasses

4. what is better - fewer bigger flashes or more small flashes (assuming the same ''fire output'')

Since you are the "expert" from down under, which is better, Broadflash Harlegin Opal or pinfire, and which is more noticeable from greater distances? Get the point!

 

[adamasgem]

Date: 6/2/2005 2:13:13 AM
Author: valeria101

Date: 6/2/2005 1:26:40 AM
Author: Garry H (Cut Nut)


2. I have an ongoing debate (good natured) with many people about whether diamonds should look good at 10 inches or less - (I am for 14 inches). Now we must grade fire from across the room?

Do these guys wear diamonds where they can see them ?

I can''t imagine what use of diamonds brings them closer than 10 in to the eye of the beholder for more than an occasional instance... Any ideas ? Surely I would not have asked something like this if there wasn''t a respectable amount of biometrics mentioned around here already.

Good observation.. I don''t think women want people invading their "space" just to admire their diamond.

 

[adamasgem]

Date: 6/4/2005 10:41:51 AM
Author: JohnQuixote
According to visual specialists, that is also a practical distance of accomodation (clear near focus) for all. Young''uns can focus clearly as close as 7cm. By age 45 accomodative ability drops to 25cm.

So, while close-in, it is not too close to disrupt accomodation in most of us.

Diamond graders look at stones through a microscope or close up.
Last I looked, people''s arms are maybe 30 inches away from their eyes, and USUALLY at greater distances from other peoples eyes. Fire is what catches people''s eyes and makes them want to get closer to the diamond, The closer you get to an object, relative to its size, the better the visual acuity, and ability to discern more nuances of the stone, like clarity. Better cutting produces better and stronger braodflash Fire, from my observations.

 

[JohnQuixote]

Date: 6/7/2005 12:13:37 PM
Author: adamasgem

Good observation.. I don''t think women want people invading their ''space'' just to admire their diamond.

Marty - Maybe someone will volunteer to do a study on that...

 

[JohnQuixote]

Date: 6/7/2005 12:29:12 PM
Author: adamasgem

Date: 6/4/2005 10:41:51 AM
Author: JohnQuixote
According to visual specialists, that is also a practical distance of accomodation (clear near focus) for all. Young'uns can focus clearly as close as 7cm. By age 45 accomodative ability drops to 25cm.

So, while close-in, it is not too close to disrupt accomodation in most of us.

Diamond graders look at stones through a microscope or close up.
Last I looked, people's arms are maybe 30 inches away from their eyes, and USUALLY at greater distances from other peoples eyes. Fire is what catches people's eyes and makes them want to get closer to the diamond, The closer you get to an object, relative to its size, the better the visual acuity, and ability to discern more nuances of the stone, like clarity. Better cutting produces better and stronger braodflash Fire, from my observations.

Right, but this 10" distance relates well to pedestrain observation: When a person says 'Wow, what a nice diamond.' and the ring-wearer shows it to them I think 10 inches is a quite reasonable and average range of examination.

At the JCK food court I remember this happening between me and you with your pinky ring.

 

[Garry H (Cut Nut)]

Date: 6/7/2005 12:09:50 PM
Author: adamasgem

Date: 6/2/2005 1:26:40 AM
Author: Garry H (Cut Nut)
3. No Fire I ever saw in any colorless gem was ''muddy'' - never
I suggest you might need new glasses

4. what is better - fewer bigger flashes or more small flashes (assuming the same ''fire output'')

Since you are the ''expert'' from down under, which is better, Broadflash Harlegin Opal or pinfire, and which is more noticeable from greater distances? Get the point!

3. tell me more Marty - muddy fire - when did I miss it? Why do I need special glasses to see spectral colors that are not spectral colors?
Oh - I get it I need these glasses and then pure rainbow colors

look muted. Did I get 100% Sir?

4. What is better Marty - rolling flash opal where the fire covers the stones total surface you see for 5 out of 180 degrees of stone rotation, or pinfire where 2% of the stones surface displays fire all the time?

I do not like either type, but perhaps this is a better analogy than yours

 

[adamasgem]

Date: 6/7/2005 9:35:04 PM
Author: Garry H (Cut Nut)

Date: 6/7/2005 12:09:50 PM
Author: adamasgem

Date: 6/2/2005 1:26:40 AM
Author: Garry H (Cut Nut)
3. No Fire I ever saw in any colorless gem was ''muddy'' - never
I suggest you might need new glasses

4. what is better - fewer bigger flashes or more small flashes (assuming the same ''fire output'')

Since you are the ''expert'' from down under, which is better, Broadflash Harlegin Opal or pinfire, and which is more noticeable from greater distances? Get the point!

3. tell me more Marty - muddy fire - when did I miss it? Why do I need special glasses to see spectral colors that are not spectral colors?
Oh - I get it I need these glasses and then pure rainbow colors

look muted. Did I get 100% Sir?

No, i think not.. I''m reporting what I see in the camera, purer spectral hues rather than pastels trending down to earth tones (muddy) as cut quality deminishes.

Quite frankly, I haven''t done the technical analysis yet , nor has anyone else, which would be able to explain the phenomena I have seen. Lot of work there, But, It is just there. The standard chromatic flare analyses would have to be modified to look at individual facets from the perspective of the camera, which in effect, might lend itself to reverse ray tracing techniques rather than forward monte carlo.
Additionally, my forward raytrace modeling to date has been based on pure 8 fold symmetry stones. I''ve gotten to the point where I can read in STL files and am now tring to organize then into a reduced 58 + girdle facet data set. I can probably do a very inefficient monte carlo (based on STL input, which breaks every facet into a series of triangles), but it would be a very slow processing. You need to know the 4 coefficients of each plane and then define, in proper order, the boundarys of the individual factets. The Diamondcal STL output and what you so kindly sent me from the Helium machine, will be very helpfull to me in this effort, when I get the time to address the processing issues, so I thank you for that.

It is on my list of thing to do. Do you want to fund the time, or buy a unit from me.

4. What is better Marty - rolling flash opal where the fire covers the stones total surface you see for 5 out of 180 degrees of stone rotation, or pinfire where 2% of the stones surface displays fire all the time?

Not a fair analogy or question for the subject matter being discussed here. My analogy given has to deal with observability issues. Gary, please don''t pose questions to confuse the issue. You know what I am talking about. Broad flash versus pinfire analogy for observability. Besides I think that rolling flash is sort of analogous to sintillation, which I haven''t addressed.

What is ineresting, in that respect, is that a slight movement (rotation in face up view) will ever so slightly light up individual facets differently, because of the slight aspect change to the over 5000 "light sources" used. The overall effect relative to spectral hues visible to the camera (muddy or pure) remains the same.


I do not like either type, but perhaps this is a better analogy than yours

Sorry to have missed you in Vegas, but the day of Leonids talk was a little disjointed.

 

[mmorrison]

I''m kind of jumping inbetween some experts here, but I thought I''d post my own little observation

There was one thing that made me want good cut quality diamonds for my fiancee''s wedding band -- my Grandma''s rings!

I was at lunch with her and she has two very beautiful rings and they were more firey/brilliant than anything I''ve personally seen. I was sitting across the table from her, probably 3-4 feet away. I almost felt ashamed as I just kept staring at her rings and not making eye contact with my grandparents :p

I haven''t inspected them closely, didn''t feel the need to! They did their job

 

[Maxine]

Depending on how old you are, your grandma''s rings may be cut very differenly than those of today.......My mom''s ring - although small is very firey!! But it''s also a different cut.......

 

[adamasgem]

Date: 6/9/2005 9:45:37 AM
Author: mmorrison
I'm kind of jumping inbetween some experts here, but I thought I'd post my own little observation

There was one thing that made me want good cut quality diamonds for my fiancee's wedding band -- my Grandma's rings!

I was at lunch with her and she has two very beautiful rings and they were more firey/brilliant than anything I've personally seen. I was sitting across the table from her, probably 3-4 feet away. I almost felt ashamed as I just kept staring at her rings and not making eye contact with my grandparents :p

I haven't inspected them closely, didn't feel the need to! They did their job

Older cutting styles with steeper crowns and smaller tables, have historically been associated with greater "Fire". Cutters have been trying to achieve the perfect "balance" between "fire" and "brilliance" since the days of Tolkowsky.

 

[RockDoc]

Date: 6/9/2005 4:00:30 PM
Author: adamasgem

Date: 6/9/2005 9:45:37 AM
Author: mmorrison
I''m kind of jumping inbetween some experts here, but I thought I''d post my own little observation

There was one thing that made me want good cut quality diamonds for my fiancee''s wedding band -- my Grandma''s rings!

I was at lunch with her and she has two very beautiful rings and they were more firey/brilliant than anything I''ve personally seen. I was sitting across the table from her, probably 3-4 feet away. I almost felt ashamed as I just kept staring at her rings and not making eye contact with my grandparents :p

I haven''t inspected them closely, didn''t feel the need to! They did their job

Older cutting styles with steeper crowns and smaller tables, have historically been associated with greater ''Fire''. Cutters have been trying to achieve the perfect ''balance'' between ''fire'' and ''brilliance'' since the days of Tolkowsky.

Agreed Marty

But I might add that the steeper crowns and the smaller tables, resulting in greater area of the corwn facets and increased dispersion - do so at the expense of white brilliance/ light return.

Another issue is the opinions of both consumers and the trade.... as agreement as to which is the best combination/balance varies tremendously.

Regards

Rockdoc

 

[Garry H (Cut Nut)]

Marty you are talking a whole heap of tommy rot.

Fire is spectral colors
if you have developed a method to show fire as second or third order dispersion colors then I for one will not pay you a cent for it and no one else should either.

As you can see on the thread with the calcite, it takes something like double refraction to cause 'muddy colors'.

Maybe a totally unrealistic 5000 point light source will do that.

And btw I checked the thread you keep referring to that Saergey was supposed to have got frightened of - that was all pretty wierd too.

 

[adamasgem]

Date: 6/12/2005 3:38:12 PM
Author: RockDoc

Date: 6/9/2005 4:00:30 PM
Author: adamasgem

Date: 6/9/2005 9:45:37 AM
Author: mmorrison
I''m kind of jumping inbetween some experts here, but I thought I''d post my own little observation

There was one thing that made me want good cut quality diamonds for my fiancee''s wedding band -- my Grandma''s rings!

I was at lunch with her and she has two very beautiful rings and they were more firey/brilliant than anything I''ve personally seen. I was sitting across the table from her, probably 3-4 feet away. I almost felt ashamed as I just kept staring at her rings and not making eye contact with my grandparents :p

I haven''t inspected them closely, didn''t feel the need to! They did their job

Older cutting styles with steeper crowns and smaller tables, have historically been associated with greater ''Fire''. Cutters have been trying to achieve the perfect ''balance'' between ''fire'' and ''brilliance'' since the days of Tolkowsky.

Agreed Marty

But I might add that the steeper crowns and the smaller tables, resulting in greater area of the corwn facets and increased dispersion - do so at the expense of white brilliance/ light return.

Another issue is the opinions of both consumers and the trade.... as agreement as to which is the best combination/balance varies tremendously.

Regards

Rockdoc

Without going back an reviewing the published data, my memory leads me to believe you are correct there..