Brilliancescope revisited

[agc]

I know there has been alot written on this forum about brilliancescope results and I have read them. However, I am still unclear on interpreting them. What is the difference between a high and a very high in an ideal RB? Is the difference splitting hairs and not discernable with human stereoscopic vision or is it clearly visible? If there is a clear difference between a high and a very high then how much separates the two ratings? Also, do certain combinations give a distinct look such as a high/very high/high looking more firery then other combinations? I realize BS results are for direct/bright lighting whereas Isee2 is for diffuse but I''m just trying to get a better handle on interpreting all the data available to us today.

 

[Paul-Antwerp]

The BS gives scores for ''white light'', ''colored light'' and ''scintillation''.

It is highly debatable and unlikely that the score for ''scintillation'' has any true meaning.

The machine has one fixed lighting environment (divided in a number of consecutive setups) not covering all potential lighting environments. From these particular environments, a score for white and colored light is deducted.

The validity of these scores highly depends on the validity of the lighting environments. I would guess that the score for white light in round brilliants has some meaning. In other shapes, which grab their light from a much broader area, this becomes doubtful.

And the score for colored light is doubtful, because fire depends more on the lighting environment than from anything else.

All in all, the scores as such on the BS are difficult to work with, I think. Some people however have a lot of experience with the various pics, and pay more attention to these.

Live long,

 

[agc]

Thanks Paul, I am still trying to figure out what separates a high from a very high and is it discernable with the human eye. Since the BS using a mono lens then intreprets the pixels recorded in different light views into white, color and other and then divides the white pixels by the total pixels of the diamond (for white light return) to come up with a %. What % gives high and where does it cross over to very high? Is the scale linear? 0-25% low,26-50% med, 51-75% High, 76-100% v high or is it skewed like 0-50% low, 50-85% med, 85-95% high and 96-100% v high?

 

[denverappraiser]

The scale being used is deliberately proprietary. As Paul points out, there is a fair amount of confusion as to exactly what is being measured and whether this measurement produces anything useful but also the scale being applied is the result of a secret algorythm, which makes the results meaningless beyond saying that ‘Gemex likes this one’. For many people this is sufficient but they do not make the raw data available beyond providing the 6 photographs, only their conclusions. It’s very much like when your car dealer grades one as a ‘creampuff’. This may or may not be accurate and it may be a terrific car, but if you don’t understand the scale and don’t know what is being evaluated, what have you really learned?

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[Ellen]

I would concentrate more on learning about cut and optimal numbers, plus what a good Idealscope pic looks like (which IS widely accepted as measuring light return). That should get you a nice stone.

 

[agc]

Neil,
That is the exact problem I have had with interpreting the BS as I don''t their scale and what exactly they are measuring. I had hoped someone else had figured that out.

Ellen,

I am not trying to use the BS as a stand alone test to evaluate diamonds but was trying to decide if it offered ANY value in evaluating ideal/super ideal diamonds. I am very comfortable interpreting reflector based technology images and understand good CA/PA combos etc. But what happens when you get two or three diamonds with HCA below two, excellent IS/diamxray image etc and appropriate CA/PA combos, helium scan with minimal deviation and no significant azimuth shift/yaw, but different BS results between the diamonds. I realize that more than likely all the diamonds would be "beautiful" but is the BS tellings us something useful to make a more informed decision.

 

[John P]

Date: 7/14/2008 1:53:54 PM
Author: agc

But what happens when you get two or three diamonds with HCA below two, excellent IS/diamxray image etc and appropriate CA/PA combos, helium scan with minimal deviation and no significant azimuth shift/yaw, but different BS results between the diamonds. I realize that more than likely all the diamonds would be ''beautiful'' but is the BS tellings us something useful to make a more informed decision.

Once you have such elite candidates it''s impossible to say, since taste between humans varies and diamonds of equal appeal can score differently in accordance with the mechanical metric. Look at it this way: The top five finalists in the Miss America pageant may be equally wonderful, but if you were asked to select a wife from among them would you allow some anonymous judge to do it for you? No. The “right choice” at that level is entirely personal.

In live purchasing situations a shopper’s eyes can overrule the sliding scores. You have the next best thing: The dealer you’re working with chooses to employ an abundance of tools - some of which have more credibility than others. Unlike inexperienced operators at mall stores using the Brilliancescope, your dealer has vast experience correlating its results with top diamond cuts. We can give you theory here, but he is best equipped to answer your questions in a meaningful way where taste is concerned.

 

[denverappraiser]

Date: 7/14/2008 1:53:54 PM
Author: agc
I am not trying to use the BS as a stand alone test to evaluate diamonds but was trying to decide if it offered ANY value in evaluating ideal/super ideal diamonds.

No, I don’t think the BS scores provide any information useful for your purpose.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Jewelry Appraisals in Denver

 

[lovegem]

Are the light location in the BS the same for all machines? Or they can be set at different location by the operator? The BS images (or GemEx images) gives out 6 views and I believe if the light source (the location of the light) is different, then you can''t compare two diamonds? For example, diamond 1, view 1 has a light source that is 20 cm from the diamond, whereas diamond 2, image for view 1 was captured by light source at 24 cm, then these two diamonds will not be comparable right? Of course, you can look at the scale bars, but these don''t mean much now without knowing where the lights were coming from.

 

[Garry H (Cut Nut)]

One problem with many cut grading approaches is they establish a grade system based on the best cuts.
So it is frequently possible to design a proportion combination that hits the key spots, but is a bad looking diamond. It would not be difficult to do this with the brillianscope.

this pair of ETAs images shows 2 stones - a tolkwosky 57% table and one with a 1 degree deeper pavilion. You can see how the ''circles'' change. Since the Gemex Brilliancescope does this same thing in reverse - you can imagine that all you neeed to know is the positions of the lights and one can ensure that all ones diamonds line up.

I know cutters who do this where they know the diamonds are being streamed to Gemex clients.
A bit like doping in sport? Maybe?

 

[strmrdr]

Date: 7/14/2008 6:25:29 PM
Author: Garry H (Cut Nut)
One problem with many cut grading approaches is they establish a grade system based on the best cuts.

So it is frequently possible to design a proportion combination that hits the key spots, but is a bad looking diamond. It would not be difficult to do this with the brillianscope.


this pair of ETAs images shows 2 stones - a tolkwosky 57% table and one with a 1 degree deeper pavilion. You can see how the 'circles' change. Since the Gemex Brilliancescope does this same thing in reverse - you can imagine that all you neeed to know is the positions of the lights and one can ensure that all ones diamonds line up.


I know cutters who do this where they know the diamonds are being streamed to Gemex clients.

A bit like doping in sport? Maybe?

Not really a fair duo of diamonds as the b-scope would hammer the second.

While it is true that somewhat directional diamonds with high light return score best on the b-scope that isn't a bad thing as they are some of the best looking RB diamonds to me.
Notice I said SOME there are many other types of beauty.
In general a diamond scoring h white VH color will likely have slightly more dispersion than one that scores vh/vh while the vh/vh stone will be more directional.

Using the b-scope on fancies is an exercise in disaster but it is somewhat informative to me on rounds.
The pictures are more interesting to me than the scores.

 

[John P]

Date: 7/14/2008 7:50:14 PM
Author: strmrdr

Using the b-scope on fancies is an exercise in disaster but it is somewhat informative to me on rounds.
The pictures are more interesting to me than the scores.

Bringing us full circle to the first reply...

Date: 7/14/2008 5:57:32 AM
Author: Paul-Antwerp

All in all, the scores as such on the BS are difficult to work with, I think. Some people however have a lot of experience with the various pics, and pay more attention to these.

Live long,

(new readers are invited to pop some popcorn and search "Brilliancescope" - you might even enjoy it more than Gigli).

 

[strmrdr]

What I find most interesting about the b-scope is in comparison to ASET.
ASET shows where the light is coming from, B-scope score is based on where the light is going and its intensity.

I can pretty much guarantee a diamond that scores vh/vh on the b-scope in bright direct light with the diamond pointed towards the eye is going to dazzle the person looking at it.

There are however one area that I think is totally useless and that is the scintillation score.
My personal opinion is that the b-scope and similar tools can not measure scintillation and neither can the ASET or IS.
Ray tracing can approximate it but the problem comes in when converting it to 2D to display it.
It is a 5 factor problem that has height width depth movement and intensity.

 

[John P]

Date: 7/14/2008 8:05:32 PM
Author: strmrdr

What I find most interesting about the b-scope is in comparison to ASET.
ASET shows where the light is coming from, B-scope score is based on where the light is going and its intensity.

I can pretty much guarantee a diamond that scores vh/vh on the b-scope in bright direct light with the diamond pointed towards the eye is going to dazzle the person looking at it.

There are however one area that I think is totally useless and that is the scintillation score.
My personal opinion is that the b-scope and similar tools can not measure scintillation and neither can the ASET or IS.
Ray tracing can approximate it but the problem comes in when converting it to 2D to display it.
It is a 5 factor problem that has height width depth movement and intensity.

The difference to many professionals, of course, is that Brilliancescope pretends to measure this. Ideal-Scope and ASET do not.

 

[Garry H (Cut Nut)]

Date: 7/14/2008 7:50:14 PM
Author: strmrdr


Not really a fair duo of diamonds as the b-scope would hammer the second.

I was not trying to use an actual example storm - rather to show interested people "how to do it"
It is neither hard, nor has it not been done by other DiamCalc users.
Infact I met with Randy Wagner in Vegas and asked him if he would like the brilliancescope lighting positions to be modelled in DiiamCalc - he said no, which might not be a surprise since it would be easy to see each of the images that you get some value from.

 

[strmrdr]

Date: 7/14/2008 8:14:29 PM
Author: John Pollard


The difference to many professionals, of course, is that Brilliancescope pretends to measure this. Ideal-Scope and ASET do not.

Makes a difference to me too and I try to point it out every time the B-scope is discussed.
I wish they would drop it.
I am really lukewarm on the B-scope while I can get something from it but in many ways it is very flawed. So are all the other tools in their own ways. The ultimate diamond performance tool hasn't been invented yet and likely never will. DiamCalc comes closest but suffers from GIGO(garbage scans in garbage out, which is one reason why it isn't a grading tool) DC is the best diamond design and design evaluation tool available however.
If the B-scope report is available I will use it as one of my tools but it far from the most important one.