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IdealScope - Symmetry vs Light Return

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BlingChaser

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I just bought myself an idealscope and somehow decided to go for the Expert model (I figured if i was going to spend some serious dosh on a stone, what''s an extra $40).

I also printed myself the IS reference charts.

Is it possible for a round diamond to have clearly defined black arrows but can still exhibit poor light return?

Or another way of phrasing that question would be:

Does excellent or very good symmetry ensure at least fair light return?

I find the idealscope very useful to evaluate symmetry but i''m having a tough time gauging light return.

Thanks
 

Regular Guy

Ideal_Rock
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Date: 11/20/2006 11:00:36 AM
Author:BlingChaser

Is it possible for a round diamond to have clearly defined black arrows but can still exhibit poor light return?

Does excellent or very good symmetry ensure at least fair light return?

I find the idealscope very useful to evaluate symmetry but i''m having a tough time gauging light return.

Thanks
1) Absolutely possible (though not sure how likely)
2) no, does not ensure..you can have H&A and bad crown & pavillion combinations
3) I''m sympathetic...but the IS by design is used to assess light return.

Hopefully others may chime in with helpful suggestions.
 

JohnQuixote

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Date: 11/20/2006 11:00:36 AM
Author:BlingChaser

Does excellent or very good symmetry ensure at least fair light return?

I find the idealscope very useful to evaluate symmetry but i''m having a tough time gauging light return.

Thanks
It''s possible to have a diamond with great optical symmetry (H&A) that does not have great light return. Look for robust red surrounding the black arrows, especially under the table. The ideal-scope was designed to gauge light return and is very good at this.

* Black areas indicate light returned at very high angles. These areas are dark in the ideal-scope because light from directly above is blocked by the camera.

* Red areas indicate light returning to the eye at optimum angles. This should be maximized.

* Very light red/pink areas indicate less optimum light return.

* White indicates non-reflecting facets where light is escaping, or ‘leaking’ out of the diamond’s pavilion.

The finest cut diamonds have an abundance of red, and a pattern of symmetrical black arrows radiating from the center. Diamonds of average cut have areas of pink, gray and white leakage. Poorly cut diamonds have large areas of leakage and often show chaotic optical symmetry.
 

BlingChaser

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When i look at the Ideal-Scope Reference chart:

http://www.ideal-scope.com/using_reference_chart.asp

I noticed that in the first row of idealscope pictures for "Light Return", all those pictures that exhibit "good", "fair", and "poor" light return did not have clearly defined arrows.

At this point, rightly or wrongly, i had come to my own personal conclusion that decent arrows might imply at least "good" light return.

In terms of the color (red, pink, light pink, white), i seem to get different results depending on the surround lighting and background. so still experimenting on that front.
 

Regular Guy

Ideal_Rock
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you might check out the "ideal light." I did, but I''ve not gotten to use the whole package much...many others have.
 

JohnQuixote

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Date: 11/20/2006 12:06:27 PM
Author: BlingChaser
When i look at the Ideal-Scope Reference chart:

http://www.ideal-scope.com/using_reference_chart.asp

I noticed that in the first row of idealscope pictures for ''Light Return'', all those pictures that exhibit ''good'', ''fair'', and ''poor'' light return did not have clearly defined arrows.

At this point, rightly or wrongly, i had come to my own personal conclusion that decent arrows might imply at least ''good'' light return.
In the majority of cases I think you''ll find that your conclusion is good. The arrows are the pavilion mains. A well-cut diamond will often show good arrows as a result of the care taken in its craftsmanship. Nevertheless, look for the consistency of the red.


In terms of the color (red, pink, light pink, white), i seem to get different results depending on the surround lighting and background. so still experimenting on that front.
Depending on the model of IS you''re using, the ambient lighting and strength of light source under the stone the hue changes. Look for consistency of the hue throughout the diamond - not for how dark or light the overall red is.
 

JohnQuixote

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For example: Here is a simulated ideal-scope for a diamond with good arrows but light return issues caused by an extremely steep crown. There is major leakage (white) under the table. Such examples are rare, but ideal-scope analysis shows this issue.

IS-Sim-407-369.jpg
 

belle

Super_Ideal_Rock
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Date: 11/20/2006 12:13:45 PM
Author: JohnQuixote


Depending on the model of IS you''re using, the ambient lighting and strength of light source under the stone the hue changes. Look for consistency of the hue throughout the diamond - not for how dark or light the overall red is.
i think sir john answered your questions very well in his posts above, i would just like to reiterate the importance of the highligted part in this quote. make sure you look at the overall eveness and saturation of color through the idealscope. areas of white/grey or uneven lighter overall color (make sure the diamond is not tilted) indicate leakage.
 

starryeyed

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Hi Bling Chaser.

I will defer to the experts regarding how to read the ideal-scope images, but just thought I''d throw in my 2 cents as a consumer similar to you.

I also recently bought the expert ideal-scope in order to help with my diamond purchase. However, because I knew I would be looking at different diamonds with different vendors under differing light conditions, I opted to purchase the ideal-scope LIGHT in addition. This allowed me to take ambient lighting out of the equation and have a level playing field for evaluating each diamond''s light performance.

I''m not sure if you noticed, but the expert idealscope is also really helpful in locating inclusions. I have used a loupe, but the idealscope was much easier for my untrained eye. By moving the idealscope in-and-out, I could focus on different areas/planes within the diamond and easily locate the inclusions.

THE IDEAL-SCOPE ROCKS!!
 

BlingChaser

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Thank you all for your responses especially to Sir John.

Sir John:
In the simulated ideal-scope, i just noticed that there are some pink arrows between the dark eight arrows. Are these of any importance? ( i hope i''m not opening a can of worms here).

Belle:
I will look for consistency of hue but sometimes if the overall hue is pink, due to my poor choice of background lighting, i do have trouble telling pink from pale pink. At one point, i almost threw the rock away as i had a tremendous amount of white which turned out to be glare.

Starryeyed:
Yup, i just ordered myself an ideal light and i did experience the relative easiness of locating inclusions with the ideal scope. I believe they come up as black spots although i think feathers might be a different issue.
 

belle

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Date: 11/20/2006 12:44:50 PM
Author: BlingChaser

Belle:
I will look for consistency of hue but sometimes if the overall hue is pink, due to my poor choice of background lighting, i do have trouble telling pink from pale pink. At one point, i almost threw the rock away as i had a tremendous amount of white which turned out to be glare.
if you are getting good, even saturation, it won''t matter if the color is just pink or a lighter/darker version of it. the key is in the eveness of the saturation. if you have a well cut stone, it will be evenly saturated throughout. a stone that is not as well cut will have ''hot spots'' or uneven color. just look for the consistency of saturation.
 

JohnQuixote

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Date: 11/20/2006 12:44:50 PM
Author: BlingChaser
Thank you all for your responses especially to Sir John.

Sir John:
In the simulated ideal-scope, i just noticed that there are some pink arrows between the dark eight arrows. Are these of any importance? ( i hope i''m not opening a can of worms here).
BC, not to worry. What you''re seeing above is a reflection dynamic caused by the large table (60%) and extremely high crown. As I mentioned, such examples would be rare.

Here''s the same diamond with a 57 table, 34.7 CA.

IS-Sim-407-347.jpg
 

JohnQuixote

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Date: 11/20/2006 1:00:47 PM
Author: belle



Date: 11/20/2006 12:44:50 PM
Author: BlingChaser

Belle:
I will look for consistency of hue but sometimes if the overall hue is pink, due to my poor choice of background lighting, i do have trouble telling pink from pale pink. At one point, i almost threw the rock away as i had a tremendous amount of white which turned out to be glare.
if you are getting good, even saturation, it won't matter if the color is just pink or a lighter/darker version of it. the key is in the eveness of the saturation. if you have a well cut stone, it will be evenly saturated throughout. a stone that is not as well cut will have 'hot spots' or uneven color. just look for the consistency of saturation.
One of the hardest things in all of this is standardizing the lighting environment. Arguably, an even greater challenge is getting the diamond perfectly level. The sellers who include reflector photos typically have years of experience and ironclad setups. Don't be too picky with your portable setup - and please don't throw the rock away!
Belle has given good advice.
 

belle

Super_Ideal_Rock
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Date: 11/20/2006 1:17:52 PM
Author: JohnQuixote

One of the hardest things in all of this is standardizing the lighting environment. Arguably, an even greater challenge is getting the diamond perfectly level. The sellers who include reflector photos typically have years of experience and ironclad setups. Don''t be too picky with your portable setup - and please don''t throw the rock away!
i totally agree, on all accounts.
and definitely don''t throw the rock away!

keep practicing blingchaser. maybe an idealight would save some of your sanity as well.
 

Garry H (Cut Nut)

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Date: 11/20/2006 12:44:50 PM
Author: BlingChaser
Thank you all for your responses especially to Sir John.

Sir John:
In the simulated ideal-scope, i just noticed that there are some pink arrows between the dark eight arrows. Are these of any importance? ( i hope i''m not opening a can of worms here).

Belle:
I will look for consistency of hue but sometimes if the overall hue is pink, due to my poor choice of background lighting, i do have trouble telling pink from pale pink. At one point, i almost threw the rock away as i had a tremendous amount of white which turned out to be glare.

Starryeyed:
Yup, i just ordered myself an ideal light and i did experience the relative easiness of locating inclusions with the ideal scope. I believe they come up as black spots although i think feathers might be a different issue.
BC if the arrows are absent it indicates the stone has a steeper deeper proportion range.

The strongest arrows exist at shallow proportions - these arrows are always easily seen with the naked eye. This model shows a very shallow stone - 40.5 pavilion and less than 30 crown angle.

Note the rays (going either way) would come from (or go to) the lens (which is black).

Do not get too hung up on a bit of pink - pink is far less leakage than our human estimation - 50% pink = about 75 light return - which is pretty good.

always arrows.JPG
 

BlingChaser

Rough_Rock
Joined
Nov 7, 2006
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Garry H:

I was not concerned about the lack of arrows but rather if the existence/prominence of arrows would necessarily imply at the very least "fair" light return as per the Ideal-Scope Reference Chart.

I was wondering if you had ever come across a diamond which had "Excellent" or "Very Good" symmetry but yet exhibited "poor" light return.
 

BlingChaser

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Date: 11/20/2006 2:42:00 PM
Author: Garry H (Cut Nut)
the good and fair stones on the top line of the chart both have excellent symmetry
I thought "Excellent" symmetry would have to exhibit clear dark arrows as per the left pic on the 2nd row.

The good and fair stone on the top line of the chart do not have any dark arrows whatsoever.

Am i confusing myself here?
 

BlingChaser

Rough_Rock
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Date: 11/20/2006 3:15:05 PM
Author: Garry H (Cut Nut)

yes, you are confused



stars show symmetry when they are there.



With deeper stones there are no stars unless you make the lhole in the pink plastic reflector bigger - then those stones would also have stars

To be on the safe side, i''ll stay away from deep stones and stick to star gazing. Hopefully the ideal-light will be able to shed some light.(pardon the pun).
 

Arcam

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"To be on the safe side, i''ll stay away from deep stones and stick to star gazing"

don''t forget to let your eyes judge what you like, no matter what tools are used to measure beauty/light return/brilliance/etc, if your eyes don''t like it, whats the point?
 
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