Rhino’s Diamond Doc Video - Brightness

[Serg]

Date: 5/3/2006 12:01:40 PM
Author: adamasgem

Date: 5/3/2006 1:15:55 AM
Author: aljdewey

.

Facts are very different from observations. Facts are not subject to interpretation; they do not change. Examples of fact:...

These are facts......statements that do not change regardless of who views them. They are not subjective in any way. They are interpretation-proof.

As per the highlighted statement above, it sounds as though you are presenting your observations as facts, and I think that''s where the scientific-ness falls down.

Well done aljdewey...

But all our ( Human) facts are apparent from our observations.
And sometimes there is too difficult to separate FACTS from OBSERVATIONS or RULES( KNOWLAGE)

 

[JohnQuixote]

Date: 5/3/2006 12:43:29 AM
Author: adamasgem

Well Rhino..
I guess the operative word is selectivity, and while I haven't made a direct comparison (because of time) between the old AGS and new AGS grades, what I previously published, and what John Polard counted up, indicated that it would be 5 times more likely to get a GIA EX than and AGS 0, not counting the fact that AGS requires an EX polishish and GIA will (and I agree with them on this) and EX or VG polish to get an EX cut.. That would probably push the likelyhood of getting a GIA EX to 8 to 10 times that of an AGS 0 cut...

While each diamond has its own characterististics, metrics based on the best posible measurements and the measured symmetry (or asymmetry) of the stone intuitively will be much better than metrics based on averaged, rounded values, and more subjective factors designed to pander to some aspects of the trade and manipulate the market via better looking paper.

We have shown here on PriceScope the statistics of color grading of AGS versus GIA grading, we note that GIA DOES NOT plot what they call non callable extra facets (which can be LARGE) to make better paper, an overlay broad cut grade range which appears to pander to the trade, all of which begs the issue of what game are the powers at GIA playing. Of course they have to raise more monies now, after the Certifigate coverup fiasco, so I guess further loosing of grading play right into the aim of generating more revenue by selling more paper for the masses...

As RockDoc has said, they are leaning toward the dark side of the force...

Here is an example of a GIA EX with a natural that remains unplotted - it also received EX in symmetry. The 3D scan shows the PA as 41.6, but the GIA report has it as 41.4.

I wonder how the market will price these GIA 'Triple X' diamonds that have issues - compared to GIA 'VG' at cherry proportions with no visible issues that have received a ding because of the painting stereotype. Many such VGs will be, arguably, far superior to some of the goods out there receiving EX.

 

[JohnQuixote]

The grading report. This was sent to me with the stipulation that I not ID the source, thus some details are blanked.

 

[JohnQuixote]

Girdle & Pavilion.

 

[JohnQuixote]

Relative to the topic of this thread - such a natural will have no influence on the face-up appearance of the diamond. Of course, the method GIA is using to judge painting/digging (via girdle profile) does not tell the story about face-up appearance either. This is a matter of craftsmanship and, more, of DISCLOSURE. Though it does not influence face-up appearance the undisclosed natural is a bit of extra weight that is tagging along with no mention. Along with rounding and the painting/digging stereotyping this is another detail lost due to what I consider a mass-grading approach. It doesn't serve those committed to grading precision and accuracy.

 

[adamasgem]

Date: 5/3/2006 4:13:52 PM
Author: JohnQuixote

Here is an example of a GIA EX with a natural that remains unplotted - it also received EX in symmetry. The 3D scan shows the PA as 41.6, but the GIA report has it as 41.4.

I wonder how the market will price these GIA ''Triple X'' diamonds that have issues - compared to GIA ''VG'' at cherry proportions with no visible issues that have received a ding because of the painting stereotype. Many such VGs will be, arguably, far superior to some of the fodder out there receiving EX.

John That''s just a little tyke compared to some that I and others have seen, especially on fancy shapes.. We got into a real discussion on an appraisal board a while back as to whether they were mistakes or not before I dug up this little internal jewel from GIA.. intentionally not plotted on public paper, however I believe they are plotted on their internal documentation. Gues it makes the paper look better, doesn''t it, such a perfect diamond isn''t it lady, especially when it is sold in a setting..

 

[Garry H (Cut Nut)]

The rest of that stone seems to be "slightly thick" ??? Not Medium?

 

[adamasgem]

Date: 5/3/2006 4:32:14 PM
Author: Garry H (Cut Nut)
The rest of that stone seems to be ''slightly thick'' ??? Not Medium?

Yah Garry, but they probably made another convenient redefinition of medium like I documented on another thread to make their"medium range" both more thinner and more thicker.. It is, of course, all about better looking paper..

 

[Rhino]

Hi Alj,

Just popped on for a moment. Thank you kindly for the explanation and clarification and the spirit in which you have written it to me. I can't help but agree with you because it totally makes sense. I do have a question for you though based on what you have said.

"It's fair to say "the stone appeared brighter TO ME." It's fair to say "In this lighting environment, I observed x." It's even fair to say "when asked, 50 casual observers each selected stone X as appearing brighter to them."

If the same comparison was shown to 50 observers in the same lighting environment (say depicting brightness) and all of them concluded that stone x was brighter, would it be fair to say it is a fact that stone x is brighter in that environment?

Once again, thank you and I look forward to hearing back from you.

Warm regards,

 

[Garry H (Cut Nut)]

Date: 5/3/2006 5:33:30 PM
Author: Rhino
Hi Alj,

Just popped on for a moment. Thank you kindly for the explanation and clarification and the spirit in which you have written it to me. I can''t help but agree with you because it totally makes sense. I do have a question for you though based on what you have said.

''It''s fair to say ''the stone appeared brighter TO ME.'' It''s fair to say ''In this lighting environment, I observed x.'' It''s even fair to say ''when asked, 50 casual observers each selected stone X as appearing brighter to them.''

If the same comparison was shown to 50 observers in the same lighting environment (say depicting brightness) and all of them concluded that stone x was brighter, would it be fair to say it is a fact that stone x is brighter in that environment?

Once again, thank you and I look forward to hearing back from you.

Warm regards,

Iy is fair to say anything you like.

But it is only fair to say those things as an authoratative claim if you document every part - clothe colors, angle and distance of viewer, etc to make for a reproducable experiment.
Then you can say "this is science"

 

[aljdewey]

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

If the same comparison was shown to 50 observers in the same lighting environment (say depicting brightness) and all of them concluded that stone x was brighter, would it be fair to say it is a fact that stone x is brighter in that environment?

No.

Consider this: There are a few religious sects who still believe today that the earth is flat and that the sun travels around the earth. Not only does their religion tell them this, but they can see it with their own eyes. When they go outside on any given day, they can see that the sun travels around the earth every day. If you asked 50 of them to observe what they saw, all 50 of them would tell you they saw the sun revolve around the earth.

Does that make it a fact? No. The sun doesn't travel around the earth; it's exactly the opposite.

A fact is something is uninterpretable and NON-SUBJECTIVE, Rhino. " 2+2=4" is a fact. There is NO other possible correct outcome. It is not subject to interpretation. It is not subjective depending on the person you ask. Every person of math-capable age will get that result no matter what their religion, height, gender or any other possible variable you add in.

In your example, it would be a fact to say "50 observers all viewed these two stones, and all 50 selected Stone X as being brighter than Stone Y." That doesn't establish as fact that Stone X *is* brighter; it only establishes as fact that 50 people selected it as being brighter.

I read an apt quote on a scientific website: "There's a vast difference between claiming something and proving something."

It applies here.

 

[jasontb]

Alj, what are you arguing here? Is your point that we can never take anything based on human observation as fact? If the stones are shown to a group large and diverse enough to be statistically representative of the entire world, can we then say that one stone is in fact brighter?

 

[belle]

the problem is, such insouciant use of words like ''fact'' and ''scientific'' based only on subjective results is extremely misleading.

it would be appropirate to state for a fact that:

1. you have two diamonds
2. you have 50 people
3. you have 50 people who have perceived one diamond to look ''brighter'' in a certain (hopefully well documented and repeatable) lighting environment.

people are subjective in their views. you can make an observation about ''brightness'' (which should be clearly defined) from these views but it shouldn''t be stated as scientific fact. scientific facts are not subjective.

 

[aljdewey]

Date: 5/3/2006 8:23:50 PM
Author: jasontb
Alj, what are you arguing here? Is your point that we can never take anything based on human observation as fact? If the stones are shown to a group large and diverse enough to be statistically representative of the entire world, can we then say that one stone is in fact brighter?

I guess I''d tell you to refer back to Leonid''s posts about what constitutes a scientific study for your answer, Jason. I don''t know how to explain it any better than Leonid already has.

"......limited observations of limited amount of stones in limited conditions and with limited observers do not allow to come to conclusions you are drawing."

 

[strmrdr]

Date: 5/3/2006 8:38:33 PM
Author: belle
the problem is, such insouciant use of words like ''fact'' and ''scientific'' based only on subjective results is extremely misleading.



it would be appropirate to state for a fact that:


1. you have two diamonds

2. you have 50 people

3. you have 50 people who have perceived one diamond to look ''brighter'' in a certain (hopefully well documented and repeatable) lighting environment.


people are subjective in their views. you can make an observation about ''brightness'' (which should be clearly defined) from these views but it shouldn''t be stated as scientific fact. scientific facts are not subjective.

hmmm there goes the entire study of diamond cut
No matter how ya slice it it is about human perception and is subjective.
If that''s true the science of diamond beauty isn''t a science at all.

You can measure the brightest diamond for a given light condition.
You can measure the most fiery diamond for a given light condition.
The b-scope already does that...
But without being subjective you can not find/state the most beautiful diamond in a given light condition.
Therefore we should all stop researching diamond cut and pack it in and work on something more worthwhile like world peace.

Lets hold hands and sit in a circle and sing "Kumbaya" :}

 

[adamasgem]

Date: 5/3/2006 10:16:05 PM
Author: strmrdr

hmmm there goes the entire study of diamond cut
No matter how ya slice it it is about human perception and is subjective.
If that''s true the science of diamond beauty isn''t a science at all.

You can measure the brightest diamond for a given light condition.
You can measure the most fiery diamond for a given light condition.
The b-scope already does that...
But without being subjective you can not find/state the most beautiful diamond in a given light condition.
Therefore we should all stop researching diamond cut and pack it in and work on something more worthwhile like world peace.

Lets hold hands and sit in a circle and sing ''Kumbaya'' :}

Strmdr... Kumbaya.. but you are probably too young to have experianced that era..

It is more complex than just saying it is "subjective" You have the fundamental optics of diamond cutting mixing with the observational envirionment (lighting, distance, angle) and the human adaptation (scotopic, photopic viewer) to that envirionment.

The limited mix of viewers, each with their particular color vision deficiencies, acuity, etc all create what we might term "subjectivity" and result in a wide variance in the "data". Even the way a particular question is asked can influence the "result".

As an example, in GIA''s hemisphere studies (which were a very good attempt at controlled study), the human pupil would be very small due to the bright background (surround) because of the way the "hemispheres" were illuminated. Generate the same illumination to the diamond by backlighting the hemispheres in a closed box with a black background, and you get a different set of "results" as the eye now sees "only" the diamond and not the background and the pupil size is increased.. even the slightest change in angle of the viewer (off normal) can significantly influence the result..

Jumping to conclusions based on a very very limited set of data under uncontrolled conditions is the problem with what has been presented...

 

[belle]

Date: 5/3/2006 10:16:05 PM
Author: strmrdr

hmmm there goes the entire study of diamond cut

(emphasis on extreme exaggeration of eye rolling here)

Date: 5/3/2006 10:16:05 PM
Author: strmrdr

No matter how ya slice it it is about human perception and is subjective.
If that''s true the science of diamond beauty isn''t a science at all.

i am not arguing that there is human perception involved. the point is that this perception cannot be stated as fact.
btw, there is much science involved in diamond cut as well but apparently there are more than a few that don''t recongize the difference between true science and that which they believe it to be.

 

[Serg]

Date: 5/3/2006 10:16:05 PM
Author: strmrdr

Date: 5/3/2006 8:38:33 PM
Author: belle
the problem is, such insouciant use of words like ''fact'' and ''scientific'' based only on subjective results is extremely misleading.



it would be appropirate to state for a fact that:


1. you have two diamonds

2. you have 50 people

3. you have 50 people who have perceived one diamond to look ''brighter'' in a certain (hopefully well documented and repeatable) lighting environment.


people are subjective in their views. you can make an observation about ''brightness'' (which should be clearly defined) from these views but it shouldn''t be stated as scientific fact. scientific facts are not subjective.

hmmm there goes the entire study of diamond cut
No matter how ya slice it it is about human perception and is subjective.
If that''s true the science of diamond beauty isn''t a science at all.

You can measure the brightest diamond for a given light condition.
You can measure the most fiery diamond for a given light condition.
The b-scope already does that...
But without being subjective you can not find/state the most beautiful diamond in a given light condition.
Therefore we should all stop researching diamond cut and pack it in and work on something more worthwhile like world peace.

Lets hold hands and sit in a circle and sing ''Kumbaya'' :}

What do you think about Vision Science? Is it not Science?

PLease see:

http://www.socsci.uci.edu/cogsci/vision/yellott_dates.html

draw attention to 1931.
Subject of research is not criteria for determination is it Science research or not.

 

[Garry H (Cut Nut)]

Fact: the guy on the right is happier than one on the left.

Agreed?

 

[Garry H (Cut Nut)]

Now move a few paces away from your computer screen

 

[JulieN]

omg

 

[Serg]

Date: 5/4/2006 4:09:08 AM
Author: Garry H (Cut Nut)
Fact the guy on the right is happier than one on the left.

Agreed?

No.
Just He looks much better(It is not mean what He is Happy)

 

[adamasgem]

Date: 5/4/2006 4:11:27 AM
Author: Garry H (Cut Nut)
Now move a few paces away from your computer screen

If you are nearsighted and are using an LCD screen, take your glasses off, move slightly away from your focus distance, and tilt the screen a bit up and down.. The "pained" expression changes.. But maybe he is happy