Why would anyone object to painting?

[Garry H (Cut Nut)]

Date: 5/27/2006 5:02:32 PM
Author: Rhino

Date: 5/26/2006 5:28:29 PM
Author: Garry H (Cut Nut)

Date: 5/26/2006 11:24:10 AM
Author: Rhino

Date: 5/25/2006 12:58:01 AM
Author: Garry H (Cut Nut)

Date: 5/24/2006 10:54:50 PM
Author: strmrdr

Date: 5/24/2006 10:32:10 PM
Author: Garry H (Cut Nut)
For all those who have DiamCalc and want to see what a diamond looks like in the cat liter box - here is my best approximation for the lighting in DiamCalc.

way too much head shadow compared to the DD, no cigar

Storm try the attached 46 degree dome lighting that gIA used as their model for obsured lighting.
I modeled it here with fading to the hemisphere light, which i think they would approve of.

Since this was the lighting model they used in their software ''metric'' that approximated the dealer lighting that the fluoro DD light aproximates - check it out and see if you think I have too much head shadow in the DD?

Hi Garry,

The white dome was used in some of the studies but none of the observation testing was performed with this. White dome stuff is kinda moot.

Rhino you claim to be an expert in this area, yet you really do not follow through before making your statements.
Read tha last line here and you will see that about 8% of GIA''s total observations were done thru this dome (5095).
http://www.gia.edu/pdfs/cut_table_1.pdf
http://www.gia.edu/pdfs/cut_table_1.pdf

great work I am sure John, but Wink - forget it - this is a non issue

Thanks for the links to the charts. Here is what they reported regarding the use of the domes in the Fall 2004 G&G article.

Early Observatoin Testing: Brightness and Fire

Our Brightness team examined a set of fire Research Diamonds, RD01 - RD05, for birghtness differences in the dome environments described above. We confirmed that the predictions of a specific brightness metric (the relative brightness order of hte five diamonds) matched the observations of hte Brightness team in the environment for that metric. We then used relative observation of 990 pairs of Research Diamonds (core reference set) in dealer-equivalent lighting to select the appropriate brightness metric; that is, we adjusted the modeling conditions (e.g., lighting conditions or viewing geometry) of our brightness metrics until we found one that predicted brightness ranking in the same order as the observational results.

According to the Fall G&G article the Brightness team did the examinations through these to see how they corellated but as far as I know none of the observers used it. Even if what your saying is accurate (that 8% did and I have no reason to doubt you) that means 92% didn''t causing me to stick to my view. Dome viewing while interesting = moot. To me, viewing a diamond in diffuse daylight that represents the assessment I''ll see in other diffuse daylight environements represents the most accurate determination for me personally since those are the environements people regularly find themselves in on a daily basis.

That doesn''t mean I''m not interested to see the lighting schemes you come up with in DiamCalc Garry to compare to common viewing for comparison.

Peace,

So the point they made in the article Rihno is that the dome lighting was used to test the resluts of the dealer lighting and their new CVE (=DD) and their old computer metrics.
So the 46 degree obstruction model got the closest results that they could model in their WLR program that matched the DD lighting results.

That is, they got their best match in preferences from a 46 degree dome and DD.

So why is that so hard to understand? (apart from the convoluted way the information was presented).

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

 

[Serg]

Date: 5/26/2006 6:10:26 PM
Author: Rhino

Hey Garry,

Heading out at this moment but I''ll definitely check em out. If I''m mistaken about the domes I''ll stand corrected but I had other info. I''ll look into and confirm.

Peace,

Rhino,
Try speak with different parts of GIA cut "Team"( not with DD FACTION only)

 

[Garry H (Cut Nut)]

bump

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)

Date: 5/27/2006 5:02:32 PM
Author: Rhino

Date: 5/26/2006 5:28:29 PM
Author: Garry H (Cut Nut)

Date: 5/26/2006 11:24:10 AM
Author: Rhino

Date: 5/25/2006 12:58:01 AM
Author: Garry H (Cut Nut)

Date: 5/24/2006 10:54:50 PM
Author: strmrdr

Date: 5/24/2006 10:32:10 PM
Author: Garry H (Cut Nut)
For all those who have DiamCalc and want to see what a diamond looks like in the cat liter box - here is my best approximation for the lighting in DiamCalc.

way too much head shadow compared to the DD, no cigar

Storm try the attached 46 degree dome lighting that gIA used as their model for obsured lighting.
I modeled it here with fading to the hemisphere light, which i think they would approve of.

Since this was the lighting model they used in their software ''metric'' that approximated the dealer lighting that the fluoro DD light aproximates - check it out and see if you think I have too much head shadow in the DD?

Hi Garry,

The white dome was used in some of the studies but none of the observation testing was performed with this. White dome stuff is kinda moot.

Rhino you claim to be an expert in this area, yet you really do not follow through before making your statements.
Read tha last line here and you will see that about 8% of GIA''s total observations were done thru this dome (5095).
http://www.gia.edu/pdfs/cut_table_1.pdf
http://www.gia.edu/pdfs/cut_table_1.pdf

great work I am sure John, but Wink - forget it - this is a non issue

Thanks for the links to the charts. Here is what they reported regarding the use of the domes in the Fall 2004 G&G article.

Early Observatoin Testing: Brightness and Fire

Our Brightness team examined a set of fire Research Diamonds, RD01 - RD05, for birghtness differences in the dome environments described above. We confirmed that the predictions of a specific brightness metric (the relative brightness order of hte five diamonds) matched the observations of hte Brightness team in the environment for that metric. We then used relative observation of 990 pairs of Research Diamonds (core reference set) in dealer-equivalent lighting to select the appropriate brightness metric; that is, we adjusted the modeling conditions (e.g., lighting conditions or viewing geometry) of our brightness metrics until we found one that predicted brightness ranking in the same order as the observational results.

According to the Fall G&G article the Brightness team did the examinations through these to see how they corellated but as far as I know none of the observers used it. Even if what your saying is accurate (that 8% did and I have no reason to doubt you) that means 92% didn''t causing me to stick to my view. Dome viewing while interesting = moot. To me, viewing a diamond in diffuse daylight that represents the assessment I''ll see in other diffuse daylight environements represents the most accurate determination for me personally since those are the environements people regularly find themselves in on a daily basis.

That doesn''t mean I''m not interested to see the lighting schemes you come up with in DiamCalc Garry to compare to common viewing for comparison.

Peace,

So the point they made in the article Rihno is that the dome lighting was used to test the resluts of the dealer lighting and their new CVE (=DD) and their old computer metrics.
So the 46 degree obstruction model got the closest results that they could model in their WLR program that matched the DD lighting results.

That is, they got their best match in preferences from a 46 degree dome and DD.

So why is that so hard to understand? (apart from the convoluted way the information was presented).

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

Rhino it would make more sense to continue this non painting discussion in this thread which purely concerns Diamond Dock and GIA''s lighting model.
https://www.pricescope.com/community/threads/gia-diamond-dock-simple-summary.42538/

Sorry for not being able to respond earlier guys. No disrespect mate but I am finding the exact opposite of what you''re claiming. When I find some time to break away I''ll expound with some photography to demonstrate what our eyes are seeing.
Peace, Rhino
GoodOldGold.com

If you do wish to take photo''s then be sure to show the room with the two ceiling lights and their relative position. You could take some with a spoon also to show the reflections of the environment too.

 

[adamasgem]

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)
So the point they made in the article Rihno is that the dome lighting was used to test the resluts of the dealer lighting and their new CVE (=DD) and their old computer metrics.
So the 46 degree obstruction model got the closest results that they could model in their WLR program that matched the DD lighting results.

That is, they got their best match in preferences from a 46 degree dome and DD.

So why is that so hard to understand? (apart from the convoluted way the information was presented).

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

Garry, It is sort of useless to try to model the KittyDock(TM) because it is not a "controlled" analytical envirionment, unlike the "controlled" envirionments of the hemispheres, which attempeted to limit the monocular look angle.

The KittyDock(TM) bares little, or no, physically correlatable relationship to the +/- 23 degree Hemisphere other than that GIA says it (the 23 degree hemispher) gave the best match to their (overall ?) "observational" studies.

That is what happens when spin "doctors" try to explain "results" they couldn''t understand.

Not to be unexpected when linear models are used to try to model highly nonlinear phenomena, and when the left hand doesn''t know anything about the right hand.

Also note the highlighted above, that, as I remember it, they eliminated the WLR aspect of the whole lighting problem, because the hemispheres had fixed look-angle "ranges".

So sad..

 

[Garry H (Cut Nut)]

Date: 5/29/2006 12:48:04 PM
Author: adamasgem

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)
So the point they made in the article Rihno is that the dome lighting was used to test the resluts of the dealer lighting and their new CVE (=DD) and their old computer metrics.
So the 46 degree obstruction model got the closest results that they could model in their WLR program that matched the DD lighting results.

That is, they got their best match in preferences from a 46 degree dome and DD.

So why is that so hard to understand? (apart from the convoluted way the information was presented).

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

Garry, It is sort of useless to try to model the KittyDock(TM) because it is not a ''controlled'' analytical envirionment, unlike the ''controlled'' envirionments of the hemispheres, which attempeted to limit the monocular look angle.

The KittyDock(TM) bares little, or no, physically correlatable relationship to the +/- 23 degree Hemisphere other than that GIA says it (the 23 degree hemispher) gave the best match to their (overall ?) ''observational'' studies.

That is what happens when spin ''doctors'' try to explain ''results'' they couldn''t understand.

Not to be unexpected when linear models are used to try to model highly nonlinear phenomena, and when the left hand doesn''t know anything about the right hand.

Also note the highlighted above, that, as I remember it, they eliminated the WLR aspect of the whole lighting problem, because the hemispheres had fixed look-angle ''ranges''.

So sad..

It is sad Marty, but it seems that the dome was aan honest attempt to save the WLR computer study and make a system more like AGS''s where actual 3D scans could be graded for brillinace, fire and scintillation.
But surely they could have wondered that matching a software grading system to dealers lighting was wrong when the best match showed a 46 degree obstruction????

If GIA are guilty of anything as you like them to be - it is that they are guilty of designing a trade diamond grading system - not a consumer one.
Or maybe it is adequate for these guys? I think this is pretty close to the type of person who would see diamonds the way you would thru the dome. And he even has a carat or two

 

[diagem]

I just barged in to this post, sorry...
Interesting, you guy''s say that the (pretty) standard light used in the trade, is too narrow ranged to actually see the reflections, scintillation, etc... that the consumer sees or wants?

or am i off completely????

 

[adamasgem]

Date: 5/29/2006 4:22:05 PM
Author: Garry H (Cut Nut)
It is sad Marty, but it seems that the dome was aan honest attempt to save the WLR computer study and make a system more like AGS''s where actual 3D scans could be graded for brillinace, fire and scintillation.
But surely they could have wondered that matching a software grading system to dealers lighting was wrong when the best match showed a 46 degree obstruction????

If GIA are guilty of anything as you like them to be - it is that they are guilty of designing a trade diamond grading system - not a consumer one.
Or maybe it is adequate for these guys? I think this is pretty close to the type of person who would see diamonds the way you would thru the dome. And he even has a carat or two

I agree regarding the intent of the hemispherical studies, and I''ve repeatedly said that the original WLR concept was on the right track, only that the uniformly illuminated hemisphere model was incorrect.

It might be that they didn''t know how to correctly analyse the data they had or that they modeled the "actual" hemispherical monocular envirionments incorrectly

I disagree that they have designed a "trade" grading system, their system is as about as usefull to the trade for discrimination as it is to the consumer, other than the "trade" is now going to be able to able to wave the piece of paper and say how great their POS promotional make is.. sort of like aiding and abetting.

A lot of the trade don''t know ( or care) what it is they are selling anyhow. They now have the "tools" to prove it.

Me thinks that the gorrila might have been giving the "carat" personally to GIA management...

Or is it that the GIA gorilla is giving the "carat" to the public..

 

[Garry H (Cut Nut)]

Date: 5/29/2006 4:42:02 PM
Author: DiaGem
I just barged in to this post, sorry...
Interesting, you guy''s say that the (pretty) standard light used in the trade, is too narrow ranged to actually see the reflections, scintillation, etc... that the consumer sees or wants?

or am i off completely????

DG I am sure that many thousands of times when you are at a dealers or your own desk (with typical twin fluoro lamp) you have a habit of looking at the brightness etc of a diamond by holding the stone away from the light, under the lip of the desk, over near a window, out in a passage under a spot light (I have even been known to visit the loo) so that you can see how a diamond performs. Dealers desk lamps are for color and clarity - not cut appraisal.

 

[diagem]

Date: 5/29/2006 9:06:35 PM
Author: Garry H (Cut Nut)

Date: 5/29/2006 4:42:02 PM
Author: DiaGem
I just barged in to this post, sorry...
Interesting, you guy''s say that the (pretty) standard light used in the trade, is too narrow ranged to actually see the reflections, scintillation, etc... that the consumer sees or wants?

or am i off completely????

DG I am sure that many thousands of times when you are at a dealers or your own desk (with typical twin fluoro lamp) you have a habit of looking at the brightness etc of a diamond by holding the stone away from the light, under the lip of the desk, over near a window, out in a passage under a spot light (I have even been known to visit the loo) so that you can see how a diamond performs. Dealers desk lamps are for color and clarity - not cut appraisal.

Garry, agreed a hundred %, every diamond i finish, i will probably look at it from atleast 4-5 different light sources!!!
Office, regular room light, sun-light, yellow-homelight (especially at night), and in my opinion the most important light... regular out-door daylight.

But i will not grade my diamonds based on these lights.

 

[Garry H (Cut Nut)]

Date: 5/30/2006 3:36:44 AM
Author: DiaGem

Date: 5/29/2006 9:06:35 PM
Author: Garry H (Cut Nut)

Date: 5/29/2006 4:42:02 PM
Author: DiaGem
I just barged in to this post, sorry...
Interesting, you guy''s say that the (pretty) standard light used in the trade, is too narrow ranged to actually see the reflections, scintillation, etc... that the consumer sees or wants?

or am i off completely????

DG I am sure that many thousands of times when you are at a dealers or your own desk (with typical twin fluoro lamp) you have a habit of looking at the brightness etc of a diamond by holding the stone away from the light, under the lip of the desk, over near a window, out in a passage under a spot light (I have even been known to visit the loo) so that you can see how a diamond performs. Dealers desk lamps are for color and clarity - not cut appraisal.

Garry, agreed a hundred %, every diamond i finish, i will probably look at it from atleast 4-5 different light sources!!!
Office, regular room light, sun-light, yellow-homelight (especially at night), and in my opinion the most important light... regular out-door daylight.

But i will not grade my diamonds based on these lights.

So when you look at the photo''s taken in GIA''s Diamond Dock - do you see how they are like what you see sitting at a desk under the very strong light?

If that was an adequate way to judge cut - then why would we need to look in all those other lights

 

[diagem]

Date: 5/30/2006 3:42:23 AM
Author: Garry H (Cut Nut)

Date: 5/30/2006 3:36:44 AM
Author: DiaGem

Date: 5/29/2006 9:06:35 PM
Author: Garry H (Cut Nut)

Date: 5/29/2006 4:42:02 PM
Author: DiaGem
I just barged in to this post, sorry...
Interesting, you guy''s say that the (pretty) standard light used in the trade, is too narrow ranged to actually see the reflections, scintillation, etc... that the consumer sees or wants?

or am i off completely????

DG I am sure that many thousands of times when you are at a dealers or your own desk (with typical twin fluoro lamp) you have a habit of looking at the brightness etc of a diamond by holding the stone away from the light, under the lip of the desk, over near a window, out in a passage under a spot light (I have even been known to visit the loo) so that you can see how a diamond performs. Dealers desk lamps are for color and clarity - not cut appraisal.

Garry, agreed a hundred %, every diamond i finish, i will probably look at it from atleast 4-5 different light sources!!!
Office, regular room light, sun-light, yellow-homelight (especially at night), and in my opinion the most important light... regular out-door daylight.

But i will not grade my diamonds based on these lights.

So when you look at the photo''s taken in GIA''s Diamond Dock - do you see how they are like what you see sitting at a desk under the very strong light?

If that was an adequate way to judge cut - then why would we need to look in all those other lights

If that is your case, why grade the color of a diamond strictly based on twin or triple fluoro. light..., i notice that some of my H-I''s would look like F''s in regular day-light...

But i guess that if we start going that direction...we''ll confuse the hell out of all diamond graders... (i think they are confused enough allready.)

Am i making sense?

 

[Rhino]

Greetings all,

Hope everyone had a great weekend. I''ve since spoken with Marty over the phone and I hear where he''s coming from and agree but don''t want to jump ahead of myself either. I''ll clarify as we progress here.

Date: 5/26/2006 6:49:11 PM
Author: aljdewey

Date: 5/26/2006 5:16:26 PM
Author: Wink

Some people like the larger broader flashes from the EightStar than the smaller flashes from the H&A cut stones that I have here, and I can readily see the difference between some of the Israeli cut H&A''s that I have here and the EightStars in terms of light, but only because I have a LOT of practice at it. When I put one of Paul''s stones next to a comperable EightStar I have to weigh them to make sure I did not mix them up, even though I THINK I know which is which. Some days I will give a tiny edge to one, and some days I will give a tiny edge to the other. The differnces are very minor, and do not involve darker edges.

Wink, this really sums up well what I feel is at the heart of the issue, and mirrors my extremely limited experience with comparing them too. Every time we''ve compared, we cannot definitively pick up the differences even when we try hard, nevermind readily.

Add to that the number of really experienced folks like yourself who ALSO say ''gee, even I''m hard pressed to note the differences.....to the point that I have to WEIGH them to tell them apart! That absolutely mirrors what we experienced, too.

We hear this from a bunch of really expert eyes, and then our own experiences match that too......so it''s a bit difficult for me to get behind an assertion that ''90% of everyday consumers see a visible difference'' when so many experts who''ve seen *thousands* of stones can''t. Maybe it goes back to how the question is being framed.....''which one is brighter'' (because it prompts the expectation that one IS actually brighter). Maybe it''s not the form of the question.....I dunno.

In the more recent survey I did with the GIA Ex steep/deep vs the painted stone (whose gem file I posted in this thread) there was no predisposed bias. Nobody saw any reflector images, technological results nothing except the 2 diamonds and observed face up in the lighting environments I described. I''ve held survey''s before where folks simply answered I don''t see any difference at all (using other stones). Asking the question "Does one diamond appear brighter to you than the other?" does not lead a consumer to be swayed one way or another because any person with common sense can answer "No I don''t see any difference in appearance." Asking laymen this question is harmless and as I had stated in another thread if you are seeking consumer input on any given optical characteristic ask specifically for the information you are looking to attain (and of course show them in the appropriate environment).

Date: 5/26/2006 6:49:11 PM
Author: aljdewey

Date: 5/26/2006 5:16:26 PM
Author: Wink

I do not like the implication that painted stones are bad. I will fight it tooth and nail every time I see it. It is bad if done incorrectly. It can actually enhance the visual appearance of the stone if done correctly.

And that''s really at the heart of it for me, too. I agree that is the implication being made.....maybe unintentionally or maybe not, but the net result is the same. It is being implied.

Let me clarify exactly my implication so there is no speculation. Firstly, they are not intentional. I am not here to purposely make any diamond appear bad. Wink ... you have read my commentary over the years and know what my consistet statements are regarding the types of products we''re discussing. Have I ever, to your knowledge painted the product in bad light (pun intended

)? Of course not. Quite the contrary, (and you know this first hand Wink) I''ve been reprimanded from Leo for saying kind things about you and the product. Remember? That was when I wasn''t aware of the rule fobidding vendors such as myself for discouraging or promoting other vendors or their products.

In fact I probably would have been more sillent on this issue were it not for the wave of attacks leveled at friends of mine in the industry and the products they''re producing which I am finding absolutely nothing wrong with. In the beginning of this year I saw nothing but attack after attack and most of the issues a matter of simply not taking the time to research the issues. Over the past year I''ve come to know to a greater extent the individuals involved in developing the cut systems so when I see their work being attacked I felt it a moral responsibilty to speak up about the survey we had conducted and our own personal research into the things we have investigated so far. I have my problems with the new cut systems (both of them) which I''ll expound upon which Marty and I discussed but I express my sympathy with the painted and dug out girdle issue because I am familiar with the observational comparison. Some may not understand it but I do understand it. Does that mean I''m purposely implying that painted or dug out girdles are bad? No. As I''ve stated time and time again, if people prefer the appearance or if the painting was done to an extent where it does not impact face up appearance or neglible THEN BUY THE DARN THING. Can I get any more clear than that? I don''t have to imply anything by sharing my opinion and preference because GIA (and also AGS has as well but to a lesser extent) implied a negative with painted girdle diamonds.

Now let me share a perspective that has not yet been discussed regarding this issue and I share this speaking strictly from a businessman''s perspective.

I can tell you for a fact that the diamonds currently mainting the highest market value are those that attain the highest cut grading in both systems. Down the road, even if a layman can not see the differences from one stone to the next (painted, dug or classical) the current scheme of things is that the diamond being disqualified from the GIA Ex grade will not be in higher demand and will not fetch the highest value. How do I know? I''m on the front lines everyday here and when I am showing a consumer the details of cut and they see features disqualifying a stone from GIA''s Ex grade, their first question to me generally is how much will I save by going to the GIA VG instead of a GIA Ex? If I tell them none, guess what their decision will be 99.9% of the time even if they see no difference? Do you understand my point? They (the consumer) would really have to then strongly prefer the painted girdle diamond over the classical girdle in order to pay the same premium and any businessman with common sense will tell you that is a harder sell regardless of any individual industry professional''s personal preference.

So you see I''m approaching this subject from a few different perspectives.

Next chance I''d like to expound on what I believe are grave sins in each system but first I''d like to address Garry''s questions as I haven''t responded here in a few days.

Peace,

 

[Rhino]

Date: 5/26/2006 11:18:46 PM
Author: Garry H (Cut Nut)

Date: 5/26/2006 6:10:26 PM
Author: Rhino

Hey Garry,

Heading out at this moment but I''ll definitely check em out. If I''m mistaken about the domes I''ll stand corrected but I had other info. I''ll look into and confirm.

Peace,

While you are at it Jonathon, you might like to start your research by reading what GIA did so you understand that you can not possibly approve.
They wrote an article in Gems 7 Gemology which is available on-line here http://www.gia.edu/pdfs/cut_fall2004.pdf

In it on page 211 they wrote this:

For the Brightness and Fire teams, additional
viewing devices were sometimes employed, especially
in the early stages of investigation. To test
our axially symmetric (that is, hemisphere-like)
brightness metrics, we built patterned hemispheres
(figure 7; also, see table 1 in the Gems & Gemology
Data Depository at www.gia.edu/gemsandgemology)
of various sizes (6, 12, and 16 inches—about 15, 30,
and 41 cm—in diameter) in which the diamonds
were placed while observers evaluated their relative
brightness. The results of these hemisphere
observations were also compared to results from
the more typical trade environments discussed
above (table 4, “Brightness: verification;” see also
box A). To be rigorous in our investigation, we
examined a wider range of hemispheres than we
believed were necessary solely to test our brightness
metrics. In addition, we constructed a “fire
training station,” an environment consisting of a
light source and a long tube (figure that enabled
Fire team observers to grow accustomed to seeing
finer distinctions of dispersed colors in diamonds,
and to distinguish among diamonds with different
amounts of fire. Once they were comfortable with
the fire training station, observers made evaluations
of fire in our retail-equivalent lighting
(described above) and, eventually, in our CVE (table
4, “Fire: verification”).

Now i have always assumed that you had read the article - but the comment above (and now I see much else you have written) shows you have not read it.

If you really intend to discuss issues like Diamond Dock etc, then it would be worth your while (and save us all lots of time) if you would thoroughly read it.

Hi Garry,

I did read it and it''s not saying what you''re saying. I see that the "brightness team" used the domes in early observational testing but you specifically stated that 8% of the observers used in their observational testing used it. I emphasize the first sentence of your quote. "For the Brightness and Fire teams, additional viewing devices were sometimes employed, especially in the early stages of investigation."

Can you show me where you got this 8% figure?

Regards,

 

[Rhino]

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)

So the point they made in the article Rihno is that the dome lighting was used to test the resluts of the dealer lighting and their new CVE (=DD) and their old computer metrics.
So the 46 degree obstruction model got the closest results that they could model in their WLR program that matched the DD lighting results.

That is, they got their best match in preferences from a 46 degree dome and DD.

So why is that so hard to understand? (apart from the convoluted way the information was presented).

Hey mate,

Not hard to understand at all. I find it interesting, however I''m not in a position to criticize a 46 degree obscuration. Why? Because I have not sat and made the amount of domes that GIA used nor observed the amount of stones they used in their observational testing and compared that to natural diffuse daylight observing.

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

IMO to call it dumb is a premature judgment. Even if I could examine 5-10 stones under that dome and compare them to natural diffuse environements I could get a feel for it and make some kind of preliminary judgement but I do not criticize what I have not investigated. Sometimes what we think is dumb can actually make sense. Case in point ... your own adjustments to the ASET. I like what you did with the modified ASET you showed on the forum not too long ago AND when you consider the amount of obstruction you''ve incorporated into that *it could* be on par with over 40 degrees obstruction. Again, I refuse to judge what I have not tested but what you''re suggesting doesn''t appear to me to be worlds apart in concept. What I will say is this however ... to present this lighting model as DiamondDock lighting is inaccurate. No cigar. The image below is a comparison of a diamond in that lighting model and an actual photography taken under the DiamondDock. There is too much darkness in your model Garry which is why I agree with strmrdr''s assessment. It may depict 46 degree obstruction and there may be corellations between that and actual observation (which I don''t think anyone here has taken the time to test) but to say this is DiamondDock lighting is definitely inaccurate. The simple comparison below demonstrates the point. Not trying to be difficult mate but can you understand why strm and I conclude what we do?

Peace,
Jonathan

 

[jasontb]

Date: 5/30/2006 12:33:16 PM
Author: Rhino

Can you show me where you got this 8% figure?

Jon, I *think* you misunderstood Gary a bit. He got it by noting that in this document http://www.gia.edu/pdfs/cut_table_1.pdf

8% of the hemisphere observations (which that document describes in detail) were made through that particular dome (46-degees).

Gary: Table 4 says the domes were only used on the 46 research diamonds. While another almost 12,000 un-domed observations were made of almost 700 additional diamonds to verify the their metrics. Not that I totally get why some think the domes are so bad...but even if I accept that they are...I still don''t get why that ruins everything. Don''t these additional observations address that issue?

 

[WinkHPD]

Date: 5/30/2006 12:26:34 PM
Author: Rhino
I can tell you for a fact that the diamonds currently mainting the highest market value are those that attain the highest cut grading in both systems. Down the road, even if a layman can not see the differences from one stone to the next (painted, dug or classical) the current scheme of things is that the diamond being disqualified from the GIA Ex grade will not be in higher demand and will not fetch the highest value. How do I know? I''m on the front lines everyday here and when I am showing a consumer the details of cut and they see features disqualifying a stone from GIA''s Ex grade, their first question to me generally is how much will I save by going to the GIA VG instead of a GIA Ex? If I tell them none, guess what their decision will be 99.9% of the time even if they see no difference? Do you understand my point? They (the consumer) would really have to then strongly prefer the painted girdle diamond over the classical girdle in order to pay the same premium and any businessman with common sense will tell you that is a harder sell regardless of any individual industry professional''s personal preference.
Peace,

I agree that this is true about the perceived value of the stone, which is one of the reasons why I object so strongly to the poor decision by GIA to penalize something unfairly. It is an economic hardship being levied against Richard von Sternberg''s and Brian the Cutter''s diamonds for no valid reason other than not taking the time to properly analyze the positive benefits to the stone as painting is done by these two masters of their art.

This is one of the reasons that I prefer the AGS cutting grade system, since they actually measure the light return and allow for beneficial painting within fair limits rather than penalyze it because it is quicker than doing it correctly.

Wink

 

[Rhino]

Date: 5/30/2006 2:41:07 PM
Author: jasontb

Date: 5/30/2006 12:33:16 PM
Author: Rhino

Can you show me where you got this 8% figure?

Jon, I *think* you misunderstood Gary a bit. He got it by noting that in this document http://www.gia.edu/pdfs/cut_table_1.pdf

8% of the hemisphere observations (which that document describes in detail) were made through that particular dome (46-degees).

Gary: Table 4 says the domes were only used on the 46 research diamonds. While another almost 12,000 un-domed observations were made of almost 700 additional diamonds to verify the their metrics. Not that I totally get why some think the domes are so bad...but even if I accept that they are...I still don''t get why that ruins everything. Don''t these additional observations address that issue?

Thanks for clarifying Jason. I''m sure Garry will weigh in to confirm. When I initially read Garry''s post I thought he meant that 8% of the observations taken from their actual observation testing they performed with consumers and trade members was the case and not limited to their research teams.

All the best,

 

[Rhino]

Date: 5/30/2006 2:43:14 PM
Author: Wink

Date: 5/30/2006 12:26:34 PM
Author: Rhino
I can tell you for a fact that the diamonds currently mainting the highest market value are those that attain the highest cut grading in both systems. Down the road, even if a layman can not see the differences from one stone to the next (painted, dug or classical) the current scheme of things is that the diamond being disqualified from the GIA Ex grade will not be in higher demand and will not fetch the highest value. How do I know? I''m on the front lines everyday here and when I am showing a consumer the details of cut and they see features disqualifying a stone from GIA''s Ex grade, their first question to me generally is how much will I save by going to the GIA VG instead of a GIA Ex? If I tell them none, guess what their decision will be 99.9% of the time even if they see no difference? Do you understand my point? They (the consumer) would really have to then strongly prefer the painted girdle diamond over the classical girdle in order to pay the same premium and any businessman with common sense will tell you that is a harder sell regardless of any individual industry professional''s personal preference.

Peace,

I agree that this is true about the perceived value of the stone, which is one of the reasons why I object so strongly to the poor decision by GIA to penalize something unfairly. It is an economic hardship being levied against Richard von Sternberg''s and Brian the Cutter''s diamonds for no valid reason other than not taking the time to properly analyze the positive benefits to the stone as painting is done by these two masters of their art.

This is one of the reasons that I prefer the AGS cutting grade system, since they actually measure the light return and allow for beneficial painting within fair limits rather than penalyze it because it is quicker than doing it correctly.

Wink

Hey Wink,

While the painting issue can be debated, one thing in my mind that can not be is the issue of craftsmanship and on this I am 110% in your corner. I''m contemplating if I should start a new thread on this subject or continue in this thread. Goin to grab some lunch and will think about it more.

 

[Capitol Bill]

While the painting issue can be debated, one thing in my mind that can not be is the issue of craftsmanship and on this I am 110% in your corner. I''m contemplating if I should start a new thread on this subject or continue in this thread. Goin to grab some lunch and will think about it more.[/quote]

Rhino,

That would be a welcome thread. I''m sure Bill Bray will have a lot to say on the topic of craftsmanship, as that is what his BrayScore system emphasizes. I''ve had some wonderful (and lengthy) discussions with Bill on this topic - very interesting stuff.

Bill Scherlag

 

[WinkHPD]

Date: 5/30/2006 3:46:25 PM
Author: Capitol Bill
While the painting issue can be debated, one thing in my mind that can not be is the issue of craftsmanship and on this I am 110% in your corner. I''m contemplating if I should start a new thread on this subject or continue in this thread. Goin to grab some lunch and will think about it more.

Rhino,

That would be a welcome thread. I''m sure Bill Bray will have a lot to say on the topic of craftsmanship, as that is what his BrayScore system emphasizes. I''ve had some wonderful (and lengthy) discussions with Bill on this topic - very interesting stuff.

Bill Scherlag[/quote]
Bill, will you be in Vegas? I look forward to hearing what Bill had to say.

 

[Capitol Bill]

Wink,

I''ll be there. I get in Thursday morning. I look forward to seeing you and the rest of the P''Scope mob.

Bill

 

[adamasgem]

Date: 5/30/2006 3:33:08 PM
Author: Rhino

Hey Wink,

While the painting issue can be debated, one thing in my mind that can not be is the issue of craftsmanship and on this I am 110% in your corner. I''m contemplating if I should start a new thread on this subject or continue in this thread. Goin to grab some lunch and will think about it more.

I''ll up that to 200%..Something Rhino and I agree on. A major issue, that in part is addressed by AGS''s performance based ray tracing, and totally ignored by GIA other than their subjective symmetry assesment. GIA''s averageing and then rounding HIDES the whole issue of craftmanship and optical symmetry.

 

[adamasgem]

As an afterthought, this is what I really think is going on with the new GIA cut grading system...

 

[Garry H (Cut Nut)]

Date: 5/30/2006 2:22:47 PM
Author: Rhino

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

IMO to call it dumb is a premature judgment. Even if I could examine 5-10 stones under that dome and compare them to natural diffuse environements I could get a feel for it and make some kind of preliminary judgement but I do not criticize what I have not investigated. Sometimes what we think is dumb can actually make sense. Case in point ... your own adjustments to the ASET. I like what you did with the modified ASET you showed on the forum not too long ago AND when you consider the amount of obstruction you''ve incorporated into that *it could* be on par with over 40 degrees obstruction.You need to go back and see that thread again Jonathon - the model with a body showed less blue than the normal ASET - not more head/body shadow - less - so far you have addressed nothing of my objections. Again, I refuse to judge what I have not tested but what you''re suggesting doesn''t appear to me to be worlds apart in concept. What I will say is this however ... to present this lighting model as DiamondDock lighting is inaccurate. No cigar. The image below is a comparison of a diamond in that lighting model and an actual photography taken under the DiamondDock. There is too much darkness in your model Garry which is why I agree with strmrdr''s assessment. It may depict 46 degree obstruction and there may be corellations between that and actual observation (which I don''t think anyone here has taken the time to test) but to say this is DiamondDock lighting is definitely inaccurate. The simple comparison below demonstrates the point. Not trying to be difficult mate but can you understand why strm and I conclude what we do?

Peace,
Jonathan

Well done Jonathon - you cheated.
You did not take that photo at a normal viewing position.
No cigar, go to jail, do not pass go, do not collect $200.

Pleas retake the photo from the normal viewing distance - and also post the DiamCalc / GA model of the diamond you have chosen to photograph.

 

[Garry H (Cut Nut)]

Date: 5/30/2006 3:27:57 PM
Author: Rhino

Date: 5/30/2006 2:41:07 PM
Author: jasontb

Date: 5/30/2006 12:33:16 PM
Author: Rhino

Can you show me where you got this 8% figure?

Jon, I *think* you misunderstood Gary a bit. He got it by noting that in this document http://www.gia.edu/pdfs/cut_table_1.pdf

8% of the hemisphere observations (which that document describes in detail) were made through that particular dome (46-degees).

Gary: Table 4 says the domes were only used on the 46 research diamonds. While another almost 12,000 un-domed observations were made of almost 700 additional diamonds to verify the their metrics. Not that I totally get why some think the domes are so bad...but even if I accept that they are...I still don''t get why that ruins everything. Don''t these additional observations address that issue?

Thanks for clarifying Jason. I''m sure Garry will weigh in to confirm. When I initially read Garry''s post I thought he meant that 8% of the observations taken from their actual observation testing they performed with consumers and trade members was the case and not limited to their research teams.

All the best,

5000/70,000

 

[WinkHPD]

Geez Gary, why aren''t you on a plane somewhere over the ocean on your way to Vegas? When do you get in?

Wink

 

[Garry H (Cut Nut)]

leaving in 5 Wink

Rhino - take the phot in a seated positio - not standing

 

[adamasgem]

Date: 5/30/2006 2:22:47 PM
Author: Rhino

Date: 5/27/2006 10:04:15 PM
Author: Garry H (Cut Nut)

So if you wanted to pick the brightest diamond then look at thru a salad bowl with a huge black top. And as long as there is not a ''pattern related defficiency'' you will have the brightests and least brightest cut grading system.

Now you and I both know that is dumb to block the top 46 degrees of light. But that is what this article shows.

So back to Storm''s comment - no cigar for my lighting model - too much head shadow compared to the DD - well? Hello?

IMO to call it dumb is a premature judgment. Even if I could examine 5-10 stones under that dome and compare them to natural diffuse environements I could get a feel for it and make some kind of preliminary judgement but I do not criticize what I have not investigated. Sometimes what we think is dumb can actually make sense. Case in point ... your own adjustments to the ASET. I like what you did with the modified ASET you showed on the forum not too long ago AND when you consider the amount of obstruction you''ve incorporated into that *it could* be on par with over 40 degrees obstruction. Again, I refuse to judge what I have not tested but what you''re suggesting doesn''t appear to me to be worlds apart in concept. What I will say is this however ... to present this lighting model as DiamondDock lighting is inaccurate. No cigar. The image below is a comparison of a diamond in that lighting model and an actual photography taken under the DiamondDock. There is too much darkness in your model Garry which is why I agree with strmrdr''s assessment. It may depict 46 degree obstruction and there may be corellations between that and actual observation (which I don''t think anyone here has taken the time to test) but to say this is DiamondDock lighting is definitely inaccurate. The simple comparison below demonstrates the point. Not trying to be difficult mate but can you understand why strm and I conclude what we do?

Peace,
Jonathan

Jonathan:

I don''t think that your "picture" versus Garry''s rendering makes a valid comparison.

Technically, unless you have the diamond oriented in the EXACT SAME WAY relative to the KittyDock(TM), as the assymetric diamond, you can litterally get any picture you want. The errored scans of the diamond also invalidate your thesis with a comparison that Garry is "wrong". A tiny fraction of a degree can make all the difference in the world, especially in an assymetric lighting envirionment like the KittyDock(TM). Your pictre doesn''t demonstarte your thesis. It is like comparing apples and oranges..

 

[JohnQuixote]

Date: 5/30/2006 3:59:16 AM
Author: DiaGem

If that is your case, why grade the color of a diamond strictly based on twin or triple fluoro. light..., i notice that some of my H-I's would look like F's in regular day-light...

But i guess that if we start going that direction...we'll confuse the hell out of all diamond graders... (i think they are confused enough allready.)

Am i making sense?

Actually you make complete sense, and not just because of UV. In fact, it swerves us back to the topic of this thread:

Whether you agree with GIA’s approach or not there is great variability amongst diamonds that are painted, and not all are visibly notable differences.

As sellers on the internet, we must represent face-up color and clarity for our clients accurately and responsibly or we will not last long. The same applies to brillianteering. One of the sticking points here is that is seems like people are trying to predict how diamonds they have never seen are performing, even without knowing the variables.

Worthy of its own topic.

https://www.pricescope.com/community/threads/painting-stop-the-madness.45914/

 

[JohnQuixote]

Date: 5/27/2006 4:14:42 PM
Author: Rhino

Hi John,

Thanks for posting the graphic. From what I am told each individual diamonds girdle is examined for the extent of painting/digging plus the impact on face up appearance. While the graphics demonstrate the extent to which each degree is allowable I don''t know for sure if the graders in the labs sit there with these drawings to determine that. Your post seemed to imply that and is how I took it. Interestingly when I stop and think about it, an accurate scan of a diamond examined in the DiamCalc software (which is basically a line art drawing) does show the extent of it. I''m not sure if that''s how the graders in the labs actually do it but I''m putting in the request to find out. I''ll let ya know what I hear.

Peace,

Thanks Rhino. I''ll be interested to know what they say.