Rhino’s Diamond Doc Video - Brightness

[pricescope]

Jonathan compares the observations of brightness in many various environments to see if the DD is showing a conflicting view as others are suggesting.

Watch it from here. - large file, broadband is recommended.

Diamonds used in the video:

http://www.goodoldgold.com/diamond/2086 - deep cut
http://www.goodoldgold.com/diamond/1814 - near Tolkowski cut.

 

[strmrdr]

kicken
showed me what id allready seen that the DD with the tubes only is a reasonable lighting envirement to view diamonds.
The bright sunlinght mentioned was edited out id like to see it.
I cant wait to see the led fire comparison because its the one I have trouble matching up to the real world.
Id also like to see both tubes and leds in the DD on vid with those 2 stones also.

 

[Rhino]

Thank you for posting for me Leo.

Thanks strm,

This perhaps should have been called "part 1" because I have two follow up vids to come. The next will be comparisons in spot lighting environments for fire including direct sunlight, inside my home in the kitchen in typical "home" spot lighting, typical jewelry store spot lighting, amongst others. The 3rd in this series will then be environments in which a person can view both brightness and fire (not to mention scintillation) at the same time including the often talked about "under a tree in sunlight" view which is a beautiful view as well.

For clarification for the readers and newbies to PriceScope brightness is defined by the following labs ...

GIA Definition of Brightness

The appearance, or extent, of internal and external reflections of "white" light seen in a polished diamond when it is viewed face-up.

AGS Definition of Brightness

Brightness and its relation to contrast as defined by AGS research gemologist, Jim Caudill states...
What is Brightness?
The amount of white light returned to the observer.

What is Brilliance?
Brightness with positive contrast effects.
What is Contrast?
The light and dark patterns seen when observing a faceted diamond. It can be positive or negative in its optical effect. Usually caused by, but not limited to, the observer’s head.
Peace,

 

[jasontb]

Very nice production Jon. And the consistancy of your filming from view to view was nice.

DD view did seem to do a good job replicating the differences seen in the other environments.

Are we arguing about the DD''s usefulness as a sales tool or it''s usefullness as a grading tool? Does GIA market the DD as a sales tool?

 

[pricescope]

Date: 4/29/2006 5:09:07 PM
Author: jasontb
....

Are we arguing about the DD''s usefulness as a sales tool or it''s usefullness as a grading tool? Does GIA market the DD as a sales tool?

Not a sales tool: http://www.gia.edu/geminstrument/mySearchResults1.cfm?productID=405&display=detail&categoryID=3&name=Cut%20Analysis

 

[Rhino]

Date: 4/29/2006 5:09:07 PM
Author: jasontb
Very nice production Jon. And the consistancy of your filming from view to view was nice.

DD view did seem to do a good job replicating the differences seen in the other environments.

Are we arguing about the DD's usefulness as a sales tool or it's usefullness as a grading tool? Does GIA market the DD as a sales tool?

Hi Jason,

Thanks for the kind words & questions. Actually all/most of this footage I had shot purposely for teaching on the subject of brightness so consumers could expect what to see in various viewing environments and better understand the subject. I sincerely had no intention of arguing with anyone about the DD but such fuss was made over it I felt the need to include some commentary about it because the statements that were being made I was just simply not finding to be true. I have no axe to grind.

When I was researching the new GIA and AGS cut grading systems and learned of the use of the DD in GIA's observation testing my concern was the same as my peers which is why we sought to acquire it and put it through the paces. It came to us shortly after I had finished shooting alot of footage depicting brightness and was pleasantly surprised at how accurate the views were to the footage I had previously shot and observed. So in my mind there was and is no arguement. Diffuse daylight is diffuse daylight no matter where its coming from be it GIA, Gesswein, Kassoy, outside on a cloudy day, in my office etc. The same assessment is made.

As a grading tool I find it excellent because if one is to understand the logic behind GIA's cut grading system, this system is based primarily on "face up appearance" (although there are other factors as well). My goal was to determine if the viewing environment that they used corellated with normal everyday viewing environments which depict brightness because if it did indeed contradict what the human eyes assess in those environments that depict brightness, then there would be reason for concern and I would not have hesitated to report this as well in the course of our research.

I also think it is an excellent sales tool as well particularly for jewelry stores. Why? Becuase in most jewelry stores you are usually limited to spot lighting views which do not accurately show the appearance of brightness to the consumer. In our next video on fire and spot lighting conditions we demonstrate to the consumer how one could draw a faulty conclusion about brightness in a jewelry store atmosphere. When poop stones (like the stone in this experiment) are observed in spot lighting environments they take on a lighter body color and consumers falsely conclude it to be the "brighter" stone when in fact, once they bring the same stone into environments that accurately depict brightness ... the stone goes dead. Over the yearas I have seen many such threads by consumers. Diffuse daylight is to be encouraged as a view that every consumer should see in the jewelry store atmosphere before the purchase. The DD is a great tool for this job however it is not the only tool for the job. As you can see, one of the views included in this video was simply the diffuse daylight source off the end of my microscope. In the newly released GIA Diamond Grading lab manual they talk about the DD but do not stress it as the only device to make accurate assessments for brightness. What they do stress is a consistent viewing environment which depicts the optical characteristic of brightness and introduce a few to the reader. No frills, no hype.

Peace,

 

[Garry H (Cut Nut)]

Just one initial question Rhino.

Why did you choose such a stone?
It has very very poor symmetry - 7 degree crown angle and 3.4 degree pavilion angle variation??
Because of it the stone does not have a clearly dfined "ring of death".

But as to the reason why this stone looks bad in Diamond Dock - it is because it does not gather light from the areas where the light is in Diamond Dock.

As Sergey says - you can design a lighting to make any stone good or bad. You can also find other bad stones for any lighting and you did Rhino.

If we change ASET from 30 degrees blue to 49 degrees blue, and the red from 90 dergees to 100 degrees - then your stone shows mainly green and very little red.

Contrast that with the GIA graded Excellent steep deep that I used and that stone in an ASET lighting that looks like GIA DD - and hey presto - it has lots of red.

Now Storm you will say that the stone was being rocked. For that arguement to hold true you would need to rock the camera and the diamond in the face up position to see what I mean. If you do that Rhino - you will be stunned.

 

[Garry H (Cut Nut)]

Please note - these are not the regular ASET color angles - these are what I modelled the stones above in.
The bar chart below includees aGS"s angular seperation for the 3 stones I studied (that all had similar symmetry, girdle thickness etc for proper comparison). Note the deep stone will get light from the red zone on the GIA ASET model.

Also note from that chart that a very deep stone that Jonathon modelled would get most of its light from the back wall (= little or no light.)

So it seems you picked a stone that disproves your theory Jonathon.

 

[strmrdr]

Which am I gonna believe my own eyes or a birdscope?
Just like someone can find a diamond to look bad in any giving lighting someone can invent new theories and present them as fact to discredit anything.
Your own video proved to me that I can seperate diamonds out from one another under DD light conditions.
Also has that AGS data been verified its not like they are an unbiased party is this?
Im getting tired of crap science maybe the DD is and maybe it isnt but saying its just like this POS light box when just by looking at it they are different designs dont help much.
Neither does having to invent untested and unverified tools.
Neither does taking data as fact from a rival group.

Give me video and pictures and first hand accounts anyday over invented facts that the only backing is someone says its that way cuz it seems that way to me.

The braintrust at PS is better than that.

 

[Garry H (Cut Nut)]

This is probably more helpful - it has an overlay showing the difference between AGS and GIA lighting models - which I believe accounts for the difference in proportion results between the two grading systems.

 

[strmrdr]

things that make you go hmmmmmm

 

[strmrdr]

see next post...

 

[strmrdr]

Bright cloudy day:
the well cut diamond look bigger the bad cut diamond is very dark at the edges but towards the center the light is too bright to accurately separate the diamonds.
Not a very good grading environment.

 

[strmrdr]

bright day shade:
much easier to tell the diamonds apart.
imho a good grading envirement. not too bright not too dark.

 

[strmrdr]

dealer office lighting in tray

very bad lighting for grading diamond cut

 

[Garry H (Cut Nut)]

Date: 4/29/2006 9:05:09 PM
Author: strmrdr
Which am I gonna believe my own eyes or a birdscope?
Just like someone can find a diamond to look bad in any giving lighting someone can invent new theories and present them as fact to discredit anything.
Your own video proved to me that I can seperate diamonds out from one another under DD light conditions.
Also has that AGS data been verified its not like they are an unbiased party is this?
Im getting tired of crap science maybe the DD is and maybe it isnt but saying its just like this POS light box when just by looking at it they are different designs dont help much.
Neither does having to invent untested and unverified tools.
Neither does taking data as fact from a rival group.

Give me video and pictures and first hand accounts anyday over invented facts that the only backing is someone says its that way cuz it seems that way to me.

The braintrust at PS is better than that.

It seems you really want to support DD Storm?

The schematic sketch is just that - I am happy for you and Rhino to measure up and check all those angles and do a better sketch - I did it after I no longer had access to with just my notes and dimensions.
I also used the GIA''s photo''s from the Foundation article.

But now you are asking if AGS''s data can be verified - well many people were sent this data and you are welcome to check it with Peter. i do not believe in falsifying data - no need - not my purpose in life.

I never intended to show my video publicly because I do not really think there is much to see in it - if it convinced you of something well more power to you.

But it seems to me that GIA DD does not have a lot to support it.
I have only seen evidence that does not support it - and Rhino just provided some more.

BTW this image is the shallow 1.16ct from my Journal DD article - it was done in the same DiamCalc DD ASET lighting. No wonder they gave it the thumbs down. But in the Birdman ASET iut looks almost all red. Are you missing something Storm?

 

[strmrdr]

dealer lighting clear tray.
using this lighting to sell diamonds would be deceptive.

 

[strmrdr]

yea Garry in missing something an agenda.. i call it the way i see it and the tube lighting isnt bad.
The leds well thats another story so far.
No im not saying you made up that photo im sure ags did but is it accurate?
I allready pointed out 2 huge problems with it.
How can i verify that your modified ASET is accurate?
Sorry ill take what I see on vid, pictures and real life first, what your saying isnt matching up with it so we are disagreeing.

I dont want to support the DD anymore than I want to support the ASET I want to know how to use and apply both and learn all I can about both. I want the truth.
Iv gotten enough info on the ASET to support it. I think it does what it says it does. It provides a picture of where the light is coming from.
As the DD with just the tubes provides a realistic lighting envirement.

I have an aset and if I could afford it would have a DD but till then the videos and pictures combined with my eyes will have to do. :}

 

[strmrdr]

typical office lighting.
This and the shade are the 2 best so far.

 

[strmrdr]

microscope diffused daylight tube.

Too dark an envirement.
Could be used for cut grading but not as good as office and shade lighting.

 

[strmrdr]

Finally the DD.
As iv noted before the DD gives a slightly more gray appearance to the diamonds than some of the more open environments.
You can also see the angle of the lighting more than in some of the others.
As a cut grading tool id place it between the in the shade on a bright day and the office lighting and above the rest.
Not a bad place to be.

While I dont think it won the shot-out it is a reasonable lighting envirement.
Does that mean I agree 100% with the GIA system NO but the tube lighting in the DD isnt the reason for it.
Im looking forward to doing this with the led lighting and the mixed lighting in the DD.

 

[strmrdr]

3 best in one image with the D.D. in the center.

 

[strmrdr]

Now from Garry's vid a screenshot showing the difference in appearance under the DD of the 3 diamonds he used.
I can see the difference and the middle one gets the nod as the better diamond.
This is with tubes only.
His vid isnt as clean but its enough to show that there is a difference between the 3 stones.

 

[strmrdr]

Notice the differences in the images.
Garry shot his standing over the DD at a steep angle.
Jon shot his from the angle of someone seated infront of the D.D. as GIA shows is the way they want it done.

 

[Garry H (Cut Nut)]

Date: 4/30/2006 4:01:54 AM
Author: strmrdr
Notice the differences in the images.
Garry shot his standing over the DD at a steep angle.
Jon shot his from the angle of someone seated infront of the D.D. as GIA shows is the way they want it done.

You are wrong Storm

 

[strmrdr]

In what way?
This image clearly shows the shots were taken at high angles.
Unless ya sat down when ya shot the second half.
either way that the camera angle in relation to the lights is different is a fact.

Actually this points out a weakness unless they calibrated the eye height and distance for each viewer.
Your going to have that weakness in any environment however.
Also since each viewer could move them around each would see something slightly different.
Which brings us back to whose preferences are represented by the GIA cut grade.
imho with the possible exception of the led only lighting slightly messing things up the D.D. isnt the reason the GIA cut grading is the way it is.

 

[pricescope]

We have two or three issues/questions here so let's simplifying the discussion by separating them first.

When Jonathan sent me the video I asked what point he is trying to make with it. Jonathan replied that he wants to compare the observations of brightness in many various environments to see if the Diamond Dock is showing a conflicting view as others are suggesting.

Point #1. Compare observation of brightness. It is rather broad subject though and what the video actually does is comparing two specific stones: close to Tolkowski and very deep cut.

Indeed, the video shows that these diamonds look different in all 5 or 6 lightning conditions including GIA Diamond Dock. I hope we are in agreement here.

Point #2. Does Diamond Dock shows conflicting view. Jonathan and Strmrdr answer is "no". My question is: conflicting with what?

Possible conflict #1: one of the diamonds looks better in some lightning and worse in some others. NO, we didn't see this type of conflict with these diamonds. The poor deep sucker looks bad in all testing conditions in the video.

Possible conflict #2: Diamond Dock shows conflicting view of each diamond comparing to the other real life lightning environments. I think the answer is YES.

Except the bright luminescent desk lamp lighting (diamond dealers' environment) (which is obviously similar to DD because of the bright luminescent tube close to the diamond), each particular diamond look different in the daylight (shade or sun) and office lightning. See picture below.

Point #3. (Subjective) Does the video shows diamonds correctly? (It is my personal/subjective opinion and other people might see it differently) I think the diamonds in the real life (daylight, office, etc) look differently than in the video. There might be different reasons for that: real size of the sparkles, stereo vision, human eye adaptation, etc. Again, it is my subjective opinion and other folks can disagree on that.

I suggest the following conclusions:

a. The video shows that this poorly (very deep) cut diamond looks worse than ideal cut stone in such lightning conditions as daylight, office, desk lamp and Diamond Dock. No "conflicting view" for these particular stones. The video might be helpful for consumers who have never seen or compared diamonds especially poor cut next to ideal cut stones.

b. The video shows that each diamond in the Diamond Dock look somewhat similar to the diamond dealers lightning environment and different in other real life conditions (daylight, office). Therefore, there is "conflicting view".

c. The video does not support Jonathan's comment that it demonstrates the logic behind GIA research. Quite contrary, the video shows that each diamonds look different in Diamond Dock and in different real life lightning conditions. Therefore, the video doesn't prove that Diamond Dock can be used to predict any diamond appearance in other lightning conditions.

d. As Garry demonstrated above and Sergey stated a while ago, there are different combinations of proportions that won't look good in Diamond Dock while can look good in other real life lighting. Therefore, more observations of different diamonds (different combinations of proportions) in different lighting conditions is required in order to derive to reliable conclusions about usability of the Diamond Dock and accuracy of the GIA cut grading system.

Summary: Although the video is helpful to those who never seen/compared different diamonds, it cannot be called "education" or "tutorial" in the real meaning of these words and doesn't prove the concept behind using the Diamond Dock.

Personal comment: Such analysis of pros and cons is rather time consuming and since we have pretty serious differences in understanding what constitute true scientific experiment and drawn conclusions, I suggest anybody who submit educational materials (video, articles, etc.) for publishing on this site to keep it up to certain scientific standards.

 

[pricescope]

I made smaller clips (muted) from the original video for different lightning conditions for those who have problems watching original large video file:

Daylight Sun

Daylight Shade

Desk Lamp (bright luminescent lamp close to the diamond - diamond dealer's lightning)

Desk Lamp & Transparent Tray

Office Lights (luminescent tubes in the ceilings)

Diamond Dock

 

[strmrdr]

Jon didnt mention my main questions and what I consider the most important question:
Is the D.D.with tubes only a reasonable environment for diamond performance grading/testing/observation?

I believe the answer to that at this point is yes.

Notice I said reasonable there is no perfect environment.

Does that make the GIA grading system 100% right? no
because the:
people they had make the judgements
what they did with the results
What diamonds were used in the study

They are all much bigger issues than the D.D. tube lighting.

My 2c :}

 

[adamasgem]

Date: 4/29/2006 10:50:14 PM
Author: strmrdr
dealer lighting clear tray.
using this lighting to sell diamonds would be deceptive.

Storm You are posting pictures, Question, do you have a Diamond Dock and the stones?????