a different opinion on AGS 0 princess cuts

[valeria101]

Date: 9/20/2005 3:53:44 PM
Author: denverappraiser


...Frankly, I haven’t really decided if this tidbit is useful or not. (#1)

There is a real tendency to try to define what is the best image and then to judge others against that standard and this strikes me as asking for trouble. (#2)

Neil,
Thank you for the answer...

Proposition #1 tells me that adding analytical detail to the images is not the way to improve things - there is virtually more than needed anyway.

Proposition #2 tells me that allot can still be done by finding a better interpretation of those images rather than the default drift towards 'splitting hairs'.

What I am thinking is that the reflector images are basically a model with the usual problem of trading parsimony for realism.
Since showing diamonds online as over the counter is not yet an option due to constraints well beyond the point of the discussion about 'scopes, the reflector technology may not have the call to progress towards a life-like image via adding detail. As analytic method, it gains by keeping things simple and promoting smart ways of looking at diamonds through electronic communication.

Just a 0.2 worth thought...

Jonathan,
I second your reply to this post too. With a tweak...
You say there should be room for personal preferences in the top cut grade , but there is a tendency to prefer 'absolutes'. Sure so. The cut grades are the only allowing for personal preferences by design, for the others leaving as little room as possible for interpretation seems to be clearly a good thing. Since cut is counted among the 'C's... the neighborhood may well induce further bias towards 'winner takes all' cut grading. So... if allowing for flexibility is a good thing, it has to be explained - unlike looking at diamonds, looking at asset pictures does not inspire aesthetic judgment so leads for such personal interpretation have to be laid out. The set of instructions for reading Asset images does not qualify, IMO.

 

[valeria101]

Date: 9/20/2005 4:00:00 PM
Author: Rhino

Is it obvious which diamond is displaying superior contrast? Pretty big difference eh?

Is it still as obvious when the arrows are ''turned off'' (i.e. the shot is taken from a small distance so that the camera does not reflect back) ?

I am not saying it isn''t, only that this method of showijg contrast is biased towards the result. DiamCalc can probably make up an impartial model as well - so.. no problem, really.

 

[Garry H (Cut Nut)]

Some good discussion here.
Neil you have some good points too

Date: 9/20/2005 9:21:28 PM
Author: Capitol Bill
Garry,
I''ve answered the question in my mind. While you''re at it, here are three additional questions that came to mind when considering the Carre image:
What image would a flat piece of mirror produce?actually it would be blue in ASET, but if you tilt is it will show the other parts of the ASET scope.
How important is contrast?Contrats and scintillation are not things any one has seemed to work out solutions for (other than Sergey). Peter Yantzer has made it clear in presentations that they are working on it, but find it very difficult. Sergey has the tool, but we need to do loads of Human observation studies with master stones to calibrate the software to human perspective
What occurs when tilt is introduced? When buying princess cuts with ASET, I like to hold the stones in twqeezers and tilt and rock the stone
Thanks for the interesting exercise.

What was the original purpose for this thread anyway?

who cares? they can enjoy their own little world - we have work to do
Bill

The square Carre'' clearly will miss large parts of lights when there are only a few sources in a room - say one overhead and one window etc.

 

[valeria101]

Date: 9/21/2005 4:39:48 AM
Author: Garry H (Cut Nut)

The square Carre' clearly will miss large parts of lights when there are only a few sources in a room - say one overhead and one window etc.

Somewhat off topic... does the square in the picture even have a crown at all?

It just so happens that I like that shape. I was surprised to see it advertised as an 'ideal square cut' (by Ambar), knowing that attractive ones would need to be small and a 'diamond mirror' like that does not fit along the modern cuts with hundreds of facets.

 

[Serg]

Date: 9/21/2005 5:18:48 AM
Author: valeria101

Date: 9/21/2005 4:39:48 AM
Author: Garry H (Cut Nut)

The square Carre'' clearly will miss large parts of lights when there are only a few sources in a room - say one overhead and one window etc.

Somewhat off topic... does the square in the picture even have a crown at all?

It just so happens that I like that shape. I was surprised to see it advertised as an ''ideal square cut'' (by Ambar), knowing that attractive ones would need to be small and a ''diamond mirror'' like that does not fit along the modern cuts with hundreds of facets.

re:does the square in the picture even have a crown at all?

Table 86.7%
Crown height 5.4%
CrAngle1=40.55
CrAngle2=28.74

 

[Regular Guy]

You know what they say about people who assume....

Garry, where you say...

Date: 9/21/2005 4:39:48 AM
Author: Garry H (Cut Nut)

How important is contrast?Contrats and scintillation are not things any one has seemed to work out solutions for (other than Sergey). Peter Yantzer has made it clear in presentations that they are working on it, but find it very difficult. Sergey has the tool, but we need to do loads of Human observation studies with master stones to calibrate the software to human perspective

Where do you include yourself in this discussion (although, I think Leonid has suggested that your work with HCA is inclusive of research from both Diamond Calc and IS studies?)

 

[WinkHPD]

Date: 9/21/2005 2:17:38 AM
Author: Serg

Date: 9/20/2005 9:21:28 PM
Author: Capitol Bill
Garry,
I''ve answered the question in my mind. While you''re at it, here are three additional questions that came to mind when considering the Carre image:
What image would a flat piece of mirror produce?

Black in ASET light

How important is contrast?

Answer Strongly depends from definition contrast and light condition.
I sure contrast is very important, but I am not happy with IS, FS, ASET, Isee2, BS.. contrasts.

What occurs when tilt is introduced?
Thanks for the interesting exercise.

What was the original purpose for this thread anyway?

Bill

I could not find a piece of mirror, but put a small shiny knife blade on my table top ASET and got a circle of blue surrounded by red with green at the edges. I suspect a small mirror would be the same, but I do not have one available and don''t have any around that I can break to make a small enough piece...

Wink

 

[Serg]

re:I could not find a piece of mirror, but put a small shiny knife blade on my table top ASET and got a circle of blue surrounded by red with green at the edges. I suspect a small mirror would be the same, but I do not have one available and don''t have any around that I can break to make a small enough piece...

I think for
1)"big" mirror You should see black circle, than blue, red, green.
2) "small" mirror in central position you can see only black. If you will move small mirror you can see any color


Unfortunately I can not check

 

[WinkHPD]

Date: 9/21/2005 1:41:53 PM
Author: Serg

re:I could not find a piece of mirror, but put a small shiny knife blade on my table top ASET and got a circle of blue surrounded by red with green at the edges. I suspect a small mirror would be the same, but I do not have one available and don''t have any around that I can break to make a small enough piece...

I think for
1)''big'' mirror You should see black circle, than blue, red, green.
2) ''small'' mirror in central position you can see only black. If you will move small mirror you can see any color


Unfortunately I can not check

The mirror must be small enough to fit on the ASET and to allow light to get past it.

My experience with the knife blade leaves me to believe that there will not be any black, since that is what you would see as leakage (Or white if you did not use the black background) but rather with a mirror you would see only blue red and green as the light hitting the mirror will be blue and red and green.

Wink

 

[Serg]

Black should come from pupil

 

[denverappraiser]

Date: 9/21/2005 3:57:34 AM
Author: valeria101




... What I am thinking is that the reflector images are basically a model with the usual problem of trading parsimony for realism.
Since showing diamonds online as over the counter is not yet an option due to constraints well beyond the point of the discussion about 'scopes, the reflector technology may not have the call to progress towards a life-like image via adding detail. As analytic method, it gains by keeping things simple and promoting smart ways of looking at diamonds through electronic communication....

I like my Idealscope and I have little doubt that the desktop ASET is useful as well although I haven’t bought one yet. They both take the complex issue of viewing a diamond and narrow it to a specific set of conditions in order to highlight certain attributes. This sort of exercise is almost always useful as long as the viewer understands what is being highlighted and what is not. As soon as that becomes a metric, it starts to cause problems.

Take for example weight. Weight is relatively easy to measure and define but it’s only indirectly related to what most people count as desirable about a stone. Face up surface area would actually be a more direct way to describe size in the way that consumers think of it. The statement "Damn girlfriend, that's a big rock!" is not commenting on weight even though that's the closest of the traditional 4 c's that would apply. These two things are loosely related but, because there are so many customers who use certain weights as critical decision points and drive the market up at those points, there are cutters who will sacrifice other areas in order to maximize weight and, consequently, the sales price. If weight were not a primary metric, the cutters would be making different decisions. It would still be a complicated decision process but it would be a DIFFERENT set of tradeoffs. In other words, the act of choosing what to measure has not been an isolated step of observing the facts, it changed the way diamonds are processed and traded.

ASET is the same but different. It’s the same in that cutters can, and undoubtedly will, manufacture stones that result in the best ASET images as soon as there is some moderate level of agreement about what’s ‘best’ in the hopes that they can charge a premium for it. They’ll get it, and this is going to open a whole Pandora’s box of questions about what was traded off in order to maximize that particular image. We’re just beginning to touch on it in this thread and others and this debate is going to go on for years. Not everyone is going to agree but certain things will rise to prominence and will start to command a premium. Unlike weight, it’s far from established what the most desirable ASET outcome is but this is coming and consumers and dealers alike are eagerly waiting for it.

In the two subject stones, the most dramatic difference is the green/pink ratio but is this really the most important thing to be looking at? Those of us who are accustomed to comparing IS images tend to key in on it because it’s so different but it’s really still undetermined whether it’s important and, if so, how important.. The patterning in the blue may be a much bigger issue and the green/pink thing is just adding distraction.

For Internet purposes, the ASET has clear advantages over the IS because it requires a far less drastic retrofit in order to take a decent and repeatable photo. It’s bigger and the viewing stage means that there are fewer variables dependent on the skills of the photographer and those variables have a smaller effect on the final image... As we work out the grading criteria, I think this is going to become a major piece of the diamond business and the decisions about what constitute a better image will have far reaching affects. This is the ground floor of a revolution.

Neil Beaty
GG(GIA) ISA NAJA
Professional Appraisals in Denver

 

[Rhino]

Date: 9/21/2005 4:01:24 AM
Author: valeria101

Date: 9/20/2005 4:00:00 PM
Author: Rhino

Is it obvious which diamond is displaying superior contrast? Pretty big difference eh?

Is it still as obvious when the arrows are ''turned off'' (i.e. the shot is taken from a small distance so that the camera does not reflect back) ?

I am not saying it isn''t, only that this method of showijg contrast is biased towards the result. DiamCalc can probably make up an impartial model as well - so.. no problem, really.

Hi Ana,

There is difference between the 2. One displays excellent contrast the other would probably best be desribed as having too much brightness at the expense of contrast. Similar to a checkerboard without the black squares ... ie. more similar to a white piece of paper with no contrast. Like Garry uses in his example on this sites tutorial for contrast.

Peace,

 

[Rhino]

Garry:

Contrats and scintillation are not things any one has seemed to work out solutions for (other than Sergey). Peter Yantzer has made it clear in presentations that they are working on it, but find it very difficult. Sergey has the tool, but we need to do loads of Human observation studies with master stones to calibrate the software to human perspective.

I have a perspective on this you may find interesting as scintillation has been a subject of keen interest to me and how it relates to the optical signature. From what I''ve seen of Pete''s work he''s on the right track and was presented at the recent JA show.

I''ve posted the Virtual Assessment thread on the forum and hope we get some participation there relating to this metric of contrast as observed in office lighting conditions. Another virutal assessment I''d like to correllate with real direct assessment is this of scintillation and consumer responses we''ve been noting here for a long time on this subject. It will be interesting to see and record the responses of those who do it with scintillation too. Garry ... this could be a very interesting study for peeps like Sergey, you, myself and anyone interested in the assessment of cut quality as if we collect enough data Sergey can further fine tune the software to mimick the results that people are seeing in real life.

I have a virutal assessment I''d like to conduct on the subject of scintillation that may help answer some questions in the minds of many including AGS. If I am right in my observations I can point to definte features in the optical signature that causes more or less of it depending on the lighting environment.

We can talk about it here or if you prefer in im.

 

[Garry H (Cut Nut)]

Date: 9/21/2005 8:59:05 AM
Author: Regular Guy
You know what they say about people who assume....

Garry, where you say...

Date: 9/21/2005 4:39:48 AM
Author: Garry H (Cut Nut)

How important is contrast?Contrats and scintillation are not things any one has seemed to work out solutions for (other than Sergey). Peter Yantzer has made it clear in presentations that they are working on it, but find it very difficult. Sergey has the tool, but we need to do loads of Human observation studies with master stones to calibrate the software to human perspective

Where do you include yourself in this discussion (although, I think Leonid has suggested that your work with HCA is inclusive of research from both Diamond Calc and IS studies?)

Ira, the way HCA was developed is described in detail at www.diamond-cut.com.au. I used DiamCalc and the virtual ideal-scope, gilbertsonscope (the patent for ASET) etc to build charts of good and bad proportions, and other things like that.

AGS used the same steps to predict the proportion ranges for the candidates that cutters should use. But then AGS developed 3D modelling tools that they use for the actual grading. (These tools are like DiamCalc in that they give numerical results for light return, leakage, contrast and a dispersion metric).

GIA developed their data base for Facetware which does what HCA does - it looks up tables and charts of good and bad diamonds based on their prorpotions and parameters. I do not believe they used any computer studies to achieve their results - it was all based on surveys with stones of known proportions. This should work, but the light grey tray the stones were held in and the unusual lighting environemnt worry me.

All these systems become more complex and less effective with diamonds with a greater number of variables. Sergey and Yuri made me aware of this some years ago and I have given up on further development of HCA and now work together with them and Mr. Janak Mistry and associates from India.

Sergey has a vision that surpasses all others in this feild.

 

[Rhino]

Another adverse affect I am noting in this study is people''s perception of "diamond color" as the 2 stones are brought into various lighting conditions. My intent was not to even consider this aspect but with both stones being "G" in color, one diamond is being perceived, in certain lighting to be of a lower color. Interesting.

 

[DiamondExpert]

Rhino - the perceived lower color would be with the one on the left, in my opinion.

When will you shoot us some results!?

As long as I''m out on this limb, I might as well begin sawing...otherwise it won''t be any fun! ... my guesses on the B''scope bar graph results (regardless of what they may or may not mean

) are...

Left: Brilliance - lower threshold of VH or straddling VH/H; Scintillation VH (pegged or nearly so); Dispersion VH (pegged or nearly so)

Right: Brilliance - VH (pegged or nearly so); Scintillation straddling VH/H or upper H; Dispersion lower end VH

...let me know when I hit the ground!!

 

[Garry H (Cut Nut)]

Oh, BTW, re brad posting my email to him.
If anyone wants the read the unedited version of the personal email, since he has made only part of it public, then please email me (not PM) on garryh at ideal-scope.com change at to @

 

[Rhino]

Date: 9/21/2005 6:08:17 PM
Author: DiamondExpert
Rhino - the perceived lower color would be with the one on the left, in my opinion.

When will you shoot us some results!?

As long as I'm out on this limb, I might as well begin sawing...otherwise it won't be any fun! ... my guesses on the B'scope bar graph results (regardless of what they may or may not mean

) are...

Left: Brilliance - lower threshold of VH or straddling VH/H; Scintillation VH (pegged or nearly so); Dispersion VH (pegged or nearly so)

Right: Brilliance - VH (pegged or nearly so); Scintillation straddling VH/H or upper H; Dispersion lower end VH

...let me know when I hit the ground!!

Hey Gary. I'm sorry, I do not mean to string anyone along here. I was hoping to see if we could correllate direct assessment with the eyes and compare and see if that correllates with "virtual assessment" via the tools of MSU. I had started a thread there today but it seems noone is participating.

One reason it is of importance, in my eyes, is because people online are purchasing diamonds using these tools, which have their place, but do not tell the entire story regarding diamond beauty.
When I was writing and concluding my article on the Bscope I was demonstrating some of its weakness'.

I had concluded with this paragraph.

"Assessment of cut quality that focuses only on light return and not the components of contrast brilliance/scintillation and optical symmetry is not giving the entire story of cut quality. While direct light is one of the primary light sources people observe diamonds under there is a plethora more of light conditions that diamonds are observed under and there are aspects of diamond beauty that are not fully covered in the BrillianceScope analysis.





Take for example the BrillianceScope results of this stone..."

And it ends there.

Why? When I was writing that, I could not for the life of me find a diamond in the store that demonstrated this although I had witnessed this with my eyes and observations.

I see AGS being attacked by people who do not understand their science and it is bothering me to no end. I AM TRYING TO DEMONSTRATE A POINT through a simple teaching but I fear people here think I am on some kind of BrilianceScope agenda and misjudging my motives. I am friends with Jim and Pete and do my best to get inside their heads. I have videotaped their presentation and have watched it more than once along with other materials they send to me to help me understand the ASET and the logic behind it. AGS service to the industry it tops and is why I am seeking membership as an AGS jeweler. No system is flawless, this is why GIA proponents can not point a finger ... ESPECIALLY USING BRILLIANCESCOPE TECHNOLOGY, which is what we see being done on the other forum. I want to flex some brain cells around here so that my PS family will better understand the science behind AGS system. These are the intentions of my heart. No agenda but the truth. Truth has cost me a lot of money in the past when I had to choose between it and my personal convictions which I hold dear to my heart. My conscience before God comes first before any monetary gain which is why, even though I use the tools I do am quick to point out the weakness' as well as their strengths.

There is an obvious weakness I have discovered but it is not limited to just one technology. This is why I encourage direct assessment. Think outside the box with me for a moment guys. We all sell diamonds on the net eh? Well... (and please don't take this wrong, I'm not a preacher.) but the Bible teaches that if we are to be successful in what we do in life we must strive to be the best servants we can to those who solicit our help. More and more as people turn to the net for diamond purchases' more and more companies are turning to technology to *communicate* diamond beauty. Technology, as any peer of mine will point out does not work the same as the human brain does. I do not say this to boast but I work with these things daily. For a while I was by myself when our net biz was growing and all day long between emails ... scanning, picture taking, correllating ... etc. ad nauseum. as I am doing analysis questions pop into the brain ... why does this diamond look like this? What caused this change in these results? I'm the first to admit I can get geeky with this stuff but I ask these questions of myself to try to think ahead of what may be asked as a result. When questions are raised in the mind and are answered... anyone in research will tell you ... more questions are raised. Finding the answers is the journey here and keeps this interesting for me.

I see upsurges happening in this industry as GIA and AGS are responding to demand for cut grading and this is noble. At this point it is actually necessary since people who are spending their hard earned dollars want justification why one stone costs more than another and the 1 major lab that has been around for years had no cohesive answer. AGS responded in 1996 but with the introduction of optical technologies, primarily reflector based, folks like Garry, and those of us familiar with these and have correllated them to human eye observation found weakness' within the system which starting raising questions about light performance. AGS HAS RESPONDED to this in a positive manner. They are listening to voices all over the world ... including those found here at Pricescope and research that has gone into reflector based technologies.

I thought it was interesting to see certain responses, even here on the net when AGS decided to purchase the patent from Mr. Al Gilbertson for multicolored reflector tech and agreement with 8* for the further development of this technology. Does anyone find it odd that people who support reflector based tech have all been banned by this very same forum that is attacking it?!?!? Yet one of its sponsors, while criticiszing the AGS system & ASET use reflector images in their sales.

I will tell you where I see the future of online diamond trading going.

Virtual models.

Why? It is the closest thing to direct assessment that there is. We would not have to travel to Antwerp when we can have the supplier forward us a model. If we can know and learn, as a team here, how to correllate the optics we see from the model with real world assessment ... well I think you get my point. Why do you think I posed that thread on "direct assessment vs virtual assessment"? Do you vendors want to understand the needs of your clients?!? Guess what they are going to be learning how to do? I am trying to make this a fun learning process but if I am using language or coming across in a wrong manner, I apologize and will crawl back into my hole and just leave it for those who visit our site but I am trying to get everyone involved. Should this be a more private lesson? We can take it perhaps in a private section of this site.

Will you, my PS friends please encourage some participation on the virtual assessment thread? It will help those of us who are looking to serve people in a greater capacity and to further understand the strengths and weakness' of the technologies people are consulting when they make these multithousand dollar decisions. One of the strengths of the MSU software is its ability to allow a person to see and compare in different lighting conditions and is incredible to work with. Sergey is wonderful and responsive to work with and any bugs we find he is quick to fix. His service is great and is true gentleman. Let's all relax for a moment... stop sawing there my dear friend and let's all relax and have some fun eh???

Am I the only one who likes geeky toys?

I didn't want to share live consumer input just yet cause I want to *at the very least* see if the office model lighting environment correlates to the consumer input we're receiving here. Now get off your duffs and start clicking so we can all start learning about AGS and ASET!!! If consumers feel intimidated and by no means nobody should, lads... help me out here. I'm not asking anyone to lie or be dishonest in that thread. I want honest to God opinions straight from the heart. No tricks. This research, whether you guys realize it or not I will be using to help our dear friend Mr. Dave Atlas understand further the intricacies of the Imagem and exploring its strengths and weakness as they correllate to human eye observation. I plan on sending both stones to his lab for testing if we can get some results to correllate them with.

By participating we will all be serving a greater good.

Warm regards...

Your friendly neighborhood Rhino.

 

[Rhino]

Date: 9/21/2005 6:08:17 PM
Author: DiamondExpert
Rhino - the perceived lower color would be with the one on the left, in my opinion.

When will you shoot us some results!?

As long as I''m out on this limb, I might as well begin sawing...otherwise it won''t be any fun! ... my guesses on the B''scope bar graph results (regardless of what they may or may not mean

) are...

Left: Brilliance - lower threshold of VH or straddling VH/H; Scintillation VH (pegged or nearly so); Dispersion VH (pegged or nearly so)

Right: Brilliance - VH (pegged or nearly so); Scintillation straddling VH/H or upper H; Dispersion lower end VH

...let me know when I hit the ground!!

Oh... and Gary... you are correct. The one on the left.

I am curious to know what made you draw that answer so we can learn from it.

Gut?

Bscope results to come on both as soon as I can get some feedback on the other thread.

 

[Garry H (Cut Nut)]

I presume you guys are discussing the ASET images?
Not the stark images of the 2 rounds?

This whole series of threads has gotten very confusing

 

[valeria101]

Date: 9/21/2005 4:23:52 PM
Author: Rhino


There is difference between the 2. One displays excellent contrast the other would probably best be desribed as having too much brightness at the expense of contrast.

Yes, sure... only I don''t think the picture shows this conclusively: the black and white is there in plain view, black and white are in contrast allright but between the black and white in the picture and the object to be judged there isn''t more tnan a symbolic relation (or association). I was trying to point out that the respective relation or association between diamond play of light and black & white shades on 2D paper may be hiding a few things.

[to help reduce confusion on the thread following the last post by Garry - this is about the rounds].

 

[Rhino]

I would like to bring some closure to this thread before we lose focus of the original content.

Firstly let me say that the 2 ASET images posted here are of the 2 AGS princess cuts I have used in the virtual assessment thread. I have used these *purposely* because one of them has even lower BrillianceScope results than the one Brad posted on the other forum with a Low/Medium/Low vs a triple VH.

Earlier in this thread I mentioned when I viewed this diamond in office lighting I saw no problems with it at all.

Further observation testing with my staff and consumers confirmed this (which prompted the study in the other thread to see if what we were seeing could also be obsered virtually AND THE POLL CONFIRMS THIS... amazing). Sorry if this seemed I was getting off track but I needed to get opinions before I proceed to get a final answer for this situation as I am studying and researching the GIA and AGS systems and what lighting environments influence the grade most. Any answer I would have formulated would have been premature as much as it was in my heart to help here and bring closure.

Here are conclusions I am drawing based on this research.

It appears both GIA and AGS systems are considering certain lighting environments over others when considering the metric for total light performance. One of those lighting environments is that of typical common office lighting AND FOR GOOD REASON.

Brad & Co. posted an example and proceeded to point the finger at AGS, IMO prematurely due to not comprehending the science behind the BrillianceScope and how to accurately read the information it gives. A fatal error to anyone who places too much stock in any one technology. I say this because if the DiamondTalk community is going to use that as a piece of evidence against the AGS system, then it only follows suite they must use the same tactics to criticize the GIA system and if they are offering a truly *unbiased* opinion, which they claim to do, then the same criticisms should also be aimed at GIA (wait till Brad or anyone who thinks like this places a GIA Excellent with 36 crown angles and 41 paviloin angles on the BrillianceScope... they will eat those words).

In this thread and in the direct assessment thread you can all take note of the stone that won out. It is the 1.71ct G Si1 princess. Here in our store we have found the SAME correllations with direct assessment (demonstrating a great stregth of the MSU research team IMO). While the 1.71ct won out overall, here in our store the basic comments in that light condition have been along the lines of just about exactly what we're seeing in the poll.

Even the folks who have selected the 1.71ct as the winner in our direct assessment here were quick to point out that the .73ct was by no means a loser! Just their preference. BOTH ARE TRULY ABSOLUTELY GORGEOUS!

So with the slight preference for the 1.71ct ...

Here are it's BrillianceScope results...

 

[Rhino]

Do I point this out to discredit the BrillianceScope?!? Absolutely not.

What are we to learn from this?

Simple ... the BrillianceScope does not accurately assess the components of diamond beauty in office light conditions particularly assessing the components that comprise contrast. Contrast is something that delves deeper into the brain and is very tough to assess for ANY technology. Isee2 is the only one I have witnessed that does this successfully to a degree.

Before anyone thinks of hopping on the BrillianceScope bashing bandwagon I will also point out that other technologies can not accurately assess this either. So I do not want to see anyone finger pointing here as well. Office light conditions emphasize contrast through BOTH leakage and also by facets reflecting back lights and darks. It is important to many I can think of as they work in these environments every day... even more important than direct light conditions.

There is a component of the BrillianceScope analysis Brad has not shown in the other thread. I don''t think he meant to purposely hide it but if he showed it, it would probably reveal one of the flaws in the thinking there. It is the diffuse light graphic in Light View 6 which I have attached here.

The assessment of this graphic is not considered in the "bar graph results" shown on the Bscope analysis but it is a graphic that tells me other features about a diamond that relates directly to its optical signature which IN FACT DOES relate to contrast. Look at this.

 

[Rhino]

Garry, thanks for steering this back to topic.

 

[Midnight]

Jonathan,

Can you please post the BrillanceScope result of the 0.73ct for comparison. Curious to see how it looks.

 

[Paul-Antwerp]

Hey Jonathan,

Congratulations, my friend. You have offered us a fantastic example of ''out-of-the-box-thinking'', and we can learn a lot from it.

Taking a helicopter-view of the situation, I think that the advent of the AGS-system for princess-cuts has taught us a whole lot these last months. Most of these new realities always come back to the same point: ''We have based all of our knowledge about cut on the study of round brilliants in the past years, and now, we learn that we cannot take certain rules for rounds and just apply them to fancy shapes''. Here are some examples:

1. In rounds, spread is directly and inversely related to spread. Not the case in princess-cuts.

2. In rounds, the ASET-scope does not really give more info than the Idealscope. In fancy shapes however, it can make a hell of a difference. The question then is: how useful is the Idealscope in fancy shapes?

3. Today, you showed how the Brilliancescope can totally mishit on fancy shapes. I had already experienced the same phenomenon here, but you have clearly shown it.

I am sure that we will find other examples in the near future. For instance, I am wondering about the validity of a H&A-pattern (a round pattern) in squarish stones.

Anyway, I think that we have a lot to learn from studying fancy shapes, and less in going into the extreme of the round brilliant. In comparison, the round is a simple stone to study.

Compare it to the cyclist climbing a small hill in a time of 4 minutes. Then, he says: well, the Mont Ventoux is 10 times that hill, so I can climb Mont Ventoux in 40 minutes. Sorry, stupid analogy, but I could not help it. For those, who want to know, Lance Armstrong does Mont Ventoux in slightly more than an hour.

Live long,

 

[Serg]

re:1. In rounds, spread is directly and inversely related to spread. Not the case in princess-cuts.


WHY? I do not see a difference in spread for different cuts.

 

[valeria101]

Date: 9/23/2005 4:03:24 AM
Author: Paul-Antwerp


1. In rounds, spread is directly and inversely related to spread. Not the case in princess-cuts.

Should this have been: ''In rounds, spread is directly and inversely related to depth. Not the case in princess-cuts.''

Would it be feasible to give some guidelines about what range of sizes is desirable for a given weight? At least size is easy to check using only the usual lab reports and there are frequent questions about that but no refference...

 

[Paul-Antwerp]

Date: 9/23/2005 6:28:16 AM
Author: valeria101

Date: 9/23/2005 4:03:24 AM
Author: Paul-Antwerp


1. In rounds, spread is directly and inversely related to spread. Not the case in princess-cuts.

Should this have been: ''In rounds, spread is directly and inversely related to depth. Not the case in princess-cuts.''

Would it be feasible to give some guidelines about what range of sizes is desirable for a given weight? At least size is easy to check using only the usual lab reports and there are frequent questions about that but no refference...

Sorry, you are so right, Valeria.

 

[Rhino]

Dear PS family,

There is a lot more to this as we begin to explore ASET and the information it is telling us gemologically which I''d like to take to the "Virtual Assessement" thread. However my plate is full at the moment and if I do not step back and concentrate on helping my web designer I wll not progress a step there and it is imperative that I not continue to put him off.

I may not be on for a couple of days so please bear with me till that time.

Thank you kindly,