Light leakage, how can you tell in real life?

[RADIANTMAN]

Bryan - I certainly did not mean to imply that diamond sellers shouldn't talk about cut. I'm in the cut business so I'm the last person who would ever say that. I consider cut by far the most important characteristic of any diamond. There is absolutely no reason for anyone who doesn't care about cut quality to ever buy one of my diamonds.

Everyone should find a way to explain cut differences to their customers so purchase decisions can be made eyes wide open. My point was only that talking about cut and selling well cut diamonds are very different things. For example it is easy to tell a consumer that a fancy shape with a cert that reads "Ex, EX" is a fine cut and most will believe it even though it may not be true. It is equally easy to tell a customer that a diamond is well cut because the ASET shows lots of red even though that also may not be true.

Credibility does not lie in the technology you use. It lies within yourself and vendors should not be deemed more or less credible because they choose different ways to explain cut differences. I completely agree that if someone does not discuss cut at all they are extremely unlikely to be selling fine cuts. I just don't think the fact that someone talks about cut necessarily means they are selling fine cuts either though it certainly makes it more likely.

I totally agree the more that we can all agree on at least some common parameters, the easier it will be for consumers to understand and not be misled.

 

[Texas Leaguer]

Bryan - I certainly did not mean to imply that diamond sellers shouldn't talk about cut. I'm in the cut business so I'm the last person who would ever say that. I consider cut by far the most important characteristic of any diamond. There is absolutely no reason for anyone who doesn't care about cut quality to ever buy one of my diamonds.

Everyone should find a way to explain cut differences to their customers so purchase decisions can be made eyes wide open. My point was only that talking about cut and selling well cut diamonds are very different things. For example it is easy to tell a consumer that a fancy shape with a cert that reads "Ex, EX" is a fine cut and most will believe it even though it may not be true. It is equally easy to tell a customer that a diamond is well cut because the ASET shows lots of red even though that also may not be true.

Credibility does not lie in the technology you use. It lies within yourself and vendors should not be deemed more or less credible because they choose different ways to explain cut differences. I completely agree that if someone does not discuss cut at all they are extremely unlikely to be selling fine cuts. I just don't think the fact that someone talks about cut necessarily means they are selling fine cuts either though it certainly makes it more likely.

I totally agree the more that we can all agree on at least some common parameters, the easier it will be for consumers to understand and not be misled.

Stan,
I think we are 99% in agreement. Here's the only distinction that I would make. Offering a customer a report on a diamond from a well respected source, in the case of this discussion an ASET image, in my mind is a value add. Even if the seller himself does not fully understand ASET or have experience interpreting it.

Consider this parralel: a very well respected jeweler who makes a living selling engagement diamonds in the normal range gets a call for a vivid pink. He finds a diamond for the client and offers them a GIA certificate to support the sale. It has various values for color hue, saturation, tone, etc. The jeweler does not have experience with this kind of diamond. He is not an expert on the color grading system, but he provides the customer the best information available with which to consider the diamond.

ASET is a tool for understanding more about the way a given diamond is handling light. It needs to be properly interpreted for the customer to have actionable information with which to assist in his decision making. The fact that there is debate about interpretations around fancy cut diamonds is not surprising considering how much variety exists in the fancy realm. We just all need to get better at understanding those variances so that we can read them in ways that help the customer make good choices.

 

[MelisendeDiamonds]

Hi experts! so I know you can tell if a stone has light leakage from an aset image, but how do you tell in real life with a princess?

If you put something red underneath it you will see which areas of the crown appear red and are drawing light from the pavilion or leaking light out the bottom.

I actually feel like there is a not a lot of light leakage in my stone at all because in most lighting it sparkles from corner to corner, but sometimes in photos it looks dark but that may be the reflection?

Yes indeed, the camera has to get close for focus and magnification and the dark lense or body can be reflected in the diamond making the diamond look dark. This is very common in macro photographs of the brightest diamonds that gather light primarily from high angles.

i was just wondering if there were photos or something that showed examples of leakage.

See that ring of skin color underneath the table that is a pretty dramatic case of leakage.

I love my glittery stone and get compliments on how sparkly it is all the time, all this pricescope reading has me wondering though how this looks like in a real life perspective

The best way would be to compare it to others in the same lighting. Go to stores and compare to other princess cuts and try to find fine makes and look at them in many different lighting environments. I don't think this requires an ASET scope, you aren't comparing blindly over the internet your eyes in your lighting are the best judge.

 

[Garry H (Cut Nut)]

Hi experts! so I know you can tell if a stone has light leakage from an aset image, but how do you tell in real life with a princess?

If you put something red underneath it you will see which areas of the crown appear red and are drawing light from the pavilion or leaking light out the bottom.

I actually feel like there is a not a lot of light leakage in my stone at all because in most lighting it sparkles from corner to corner, but sometimes in photos it looks dark but that may be the reflection?

Yes indeed, the camera has to get close for focus and magnification and the dark lense or body can be reflected in the diamond making the diamond look dark. This is very common in macro photographs of the brightest diamonds that gather light primarily from high angles.

i was just wondering if there were photos or something that showed examples of leakage.

See that ring of skin color underneath the table that is a pretty dramatic case of leakage.

I love my glittery stone and get compliments on how sparkly it is all the time, all this pricescope reading has me wondering though how this looks like in a real life perspective

The best way would be to compare it to others in the same lighting. Go to stores and compare to other princess cuts and try to find fine makes and look at them in many different lighting environments. I don't think this requires an ASET scope, you aren't comparing blindly over the internet your eyes in your lighting are the best judge.

Thanks, you helped!

 

[Garry H (Cut Nut)]

Garry - i would definitely be interested in learning more about your cut group and what you guys do. Feel free to contact me offline.

Not that easy Stan - your website treats non US and Canadians as aliens.
You contact me

I would suggest any joint work would require you having and sharing accurate 3D scans of stones. .stl or .srn type files. Is that practical for you?

 

[Garry H (Cut Nut)]

I will add to Stan's excellent post:
About buying- Garry has suggested numerous times how I could benefit using ASET to purchase fancy shapes.
I do have one sitting here on the desk- it was quite dusty till ysssss asked about leakage.

I keep stressing the point that evaluating diamonds cut for light performance using aset is far more intuitive than for "regular" well cut Fancy Shapes.
Here's why my aset got dusty after trying to follow Garry suggestion a few years back: basically, I'd pick a stone based on the visuals, then look at the stone in the ASET.
The results are simply inconsistent.
Sometimes a band of red across the center is visible in real life, stereoscopic vision, sometimes not.
I've also found that red bands or larger red areas among a primarily green aset can be a problem.
But not always.

These aspects make calibration extremely difficult.
So in a sense, diamond cut education on PS has been boiled down to:
If we can't make some sort of a system that works for well cut radiant cuts, let's use science and buy the best cut diamond, one with a lot of red. And MAKE SURE TO GET AN ASET.

I totally get that a lot of consumers are buying blind. I also get the fact that by virtue of having and using an ASET, a seller is proving they care about quality in cut and their clients. A very good thing.
But lack of ASET is nothing sinister whatsoever. Unfortunately it's for sure that "bad" sellers are not going to use an ASET. But lack of aset, in itself, does it mean a seller is not committed to well cut, beautiful diamonds.
So figuring out better ways of assessment will benefit everyone- even some of the vendors who've been pretty tough on me in this very thread.

Nonsense David, while wasting time giving you tips it was to teach you to avoid blues especially, and reduce reds in the type of crushed ice cuts (and especially for fancy colors) that you have a market niche in.
You are practicing some of the worst demagoguery.
Go back and read the thread someone posted several posts back - and also PLEASE ANSWER SERGEYS QUESTION ABOUT FIRE (shouting intentional).

 

[Garry H (Cut Nut)]

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Serg,
It does make sense given the discussion about cyclops vs stereo vision. Do you have tools to graphically demonstrate this?

http://www.dropbox.com/sh/re5mbae49j3c3c2/68JelNAfYE
Bryan that link above will take you to a resource that we have for the 3 published and about to be published articles. There are 3D experiments there that you can play on most 3D viewing devices including 3D TV's that enable computer connection. This includes a video.
But one of the most amazing tests (kind of unrelated) that shows how messy our minds are is this image below. If you can print this to the correct size (make the stone centers 6cm apart) and use any 3D viewer - even the 18th century ones - then what will amaze you is that you see the facets under the table and not the glare. If you are good at it you can see the effect without the 3D viewer like those 3D dotty things in magazines.

 

[Rockdiamond]

Garry- sometimes a bit of red is fine- other times it is indicating areas that go dark in a way I don't find attractve- net result is inconsistency on well cut stones with a lot of green.
I answered Serg question about fire a few pages back.

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Thank you Serg

Did you notice this exchange Garry? Do you disagree with Serg?
I undestand it may be difficult to have something you created questioned. But name calling reduces the discussion for all.

 

[Serg]

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Serg,
It does make sense given the discussion about cyclops vs stereo vision. Do you have tools to graphically demonstrate this?

Bryan,

Please clarify what do you ask to demonstrate .( I think I published it on PS 7 years ago)

1)Diamcalc has stereo mode, also it shows mono pictures for left and right eye.

5-8 years ago we had long PS discussions about "Death ring"( P(41-41.5), Cr35) and GIA, AGS cut grading systems.

I published ASET images for Left and Right eye, Explained Stereo Vision and fought against most PS members.( I received a lot of critics (and real personal attacks) specially from Infinity Diamonds )
So it has to be easy to find on PS.

2) 2 years ago we built Vibox with Stereo adapter , and may now compare mono and stereo movies for same real diamonds. It gave a lot of information and confirm previous statements had been done with Diamcalc .

 

[Texas Leaguer]

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Serg,
It does make sense given the discussion about cyclops vs stereo vision. Do you have tools to graphically demonstrate this?

Bryan,

Please clarify what do you ask to demonstrate .( I think I published it on PS 7 years ago)

1)Diamcalc has stereo mode, also it shows mono pictures for left and right eye.

5-8 years ago we had long PS discussions about "Death ring"( P(41-41.5), Cr35) and GIA, AGS cut grading systems.

I published ASET images for Left and Right eye, Explained Stereo Vision and fought against most PS members.( I received a lot of critics (and real personal attacks) specially from Infinity Diamonds )
So it has to be easy to find on PS.

2) 2 years ago we built Vibox with Stereo adapter , and may now compare mono and stereo movies for same real diamonds. It gave a lot of information and confirm previous statements had been done with Diamcalc .

Serg,
I guess some of those discussions were before my time here. I will make an effort to devote some time to reading them, and also to looking at your current research. My day job gets in the way many times, unfortunately.

To clarify specifically what I was asking if you could demonstrate - do you have a picture of a diamond showing ASET from slightly different angles-representing what each eye sees independently- and an image of what the brain sees (according to current understanding of binocular rivalry, dominant eye effect, etc) when both images are processed in stereo?

The glare image Garry posted is along those lines, although I have not been able to check it out in 3D yet. But for purposes of this particular discussion, it would be informative to see the differences in ASET images.

 

[Serg]

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Serg,
It does make sense given the discussion about cyclops vs stereo vision. Do you have tools to graphically demonstrate this?

Bryan,

Please clarify what do you ask to demonstrate .( I think I published it on PS 7 years ago)

1)Diamcalc has stereo mode, also it shows mono pictures for left and right eye.

5-8 years ago we had long PS discussions about "Death ring"( P(41-41.5), Cr35) and GIA, AGS cut grading systems.

I published ASET images for Left and Right eye, Explained Stereo Vision and fought against most PS members.( I received a lot of critics (and real personal attacks) specially from Infinity Diamonds )
So it has to be easy to find on PS.

2) 2 years ago we built Vibox with Stereo adapter , and may now compare mono and stereo movies for same real diamonds. It gave a lot of information and confirm previous statements had been done with Diamcalc .

Serg,
I guess some of those discussions were before my time here. I will make an effort to devote some time to reading them, and also to looking at your current research. My day job gets in the way many times, unfortunately.

To clarify specifically what I was asking if you could demonstrate - do you have a picture of a diamond showing ASET from slightly different angles-representing what each eye sees independently- and an image of what the brain sees (according to current understanding of binocular rivalry, dominant eye effect, etc) when both images are processed in stereo?

The glare image Garry posted is along those lines, although I have not been able to check it out in 3D yet. But for purposes of this particular discussion, it would be informative to see the differences in ASET images.

Bryan,
please find ASET's images for RBC Pavilion 41.4 Crown 34.5
1) classical ASET view( Cyclopean)
2) Right Eye
3) Left Eye

a)Human Binocular vision does not work for such contradictive images
b) ASET Code Light return and Light Leakage by high intensity( White, Green, Red). So it is just garbage for Binocular rivalry

but you may see:
1) There are not big leakage zone under table for both eyes in same time( but there is big leakage zone in cyclopean ASET)
2) of Big part Crown is green for left eye and red for right eye in same time( it is very important. it is one of reason why RBS is very good cut) and via versa.( same for blue and red).
one diamond zone catch light from big angular range.

 

[RADIANTMAN]

I'll look into what's going on with my website - it should be accessible from anywhere. I use the OGI Scanox so I should be able to provide 3D scans.

 

[Texas Leaguer]

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Serg,
It does make sense given the discussion about cyclops vs stereo vision. Do you have tools to graphically demonstrate this?

Bryan,

Please clarify what do you ask to demonstrate .( I think I published it on PS 7 years ago)

1)Diamcalc has stereo mode, also it shows mono pictures for left and right eye.

5-8 years ago we had long PS discussions about "Death ring"( P(41-41.5), Cr35) and GIA, AGS cut grading systems.

I published ASET images for Left and Right eye, Explained Stereo Vision and fought against most PS members.( I received a lot of critics (and real personal attacks) specially from Infinity Diamonds )
So it has to be easy to find on PS.

2) 2 years ago we built Vibox with Stereo adapter , and may now compare mono and stereo movies for same real diamonds. It gave a lot of information and confirm previous statements had been done with Diamcalc .

Serg,
I guess some of those discussions were before my time here. I will make an effort to devote some time to reading them, and also to looking at your current research. My day job gets in the way many times, unfortunately.

To clarify specifically what I was asking if you could demonstrate - do you have a picture of a diamond showing ASET from slightly different angles-representing what each eye sees independently- and an image of what the brain sees (according to current understanding of binocular rivalry, dominant eye effect, etc) when both images are processed in stereo?

The glare image Garry posted is along those lines, although I have not been able to check it out in 3D yet. But for purposes of this particular discussion, it would be informative to see the differences in ASET images.

Bryan,
please find ASET's images for RBC Pavilion 41.4 Crown 34.5
1) classical ASET view( Cyclopean)
2) Right Eye
3) Left Eye

a)Human Binocular vision does not work for such contradictive images
b) ASET Code Light return and Light Leakage by high intensity( White, Green, Red). So it is just garbage for Binocular rivalry

but you may see:
1) There are not big leakage zone under table for both eyes in same time( but there is big leakage zone in cyclopean ASET)
2) of Big part Crown is green for left eye and red for right eye in same time( it is very important. it is one of reason why RBS is very good cut)
one diamond zone catch light from big angular range.

Very interesting Serg. I am not sure exactly what you mean by comments a and b, but comments 1 and 2 are clear.

One could then make the argument that diamonds with a mix of red and green, as seen by each eye independently, would have a promising ASET signature.

At what viewing distance does stereo vision start to give way to mono vision?

 

[Karl_K]

Garry- sometimes a bit of red is fine- other times it is indicating areas that go dark in a way I don't find attractve- net result is inconsistency on well cut stones with a lot of green.
I answered Serg question about fire a few pages back.

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Thank you Serg

Did you notice this exchange Garry? Do you disagree with Serg?
I undestand it may be difficult to have something you created questioned. But name calling reduces the discussion for all.

ASET by itself is not enough to make a decision on any stone but it sure does help if one has the information to properly interpret it for that cut.
If nothing else it gives you a somewhat uniform lighting condition to compare stones unlike "beauty" shots.

 

[Serg]

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Serg,
It does make sense given the discussion about cyclops vs stereo vision. Do you have tools to graphically demonstrate this?

Bryan,

Please clarify what do you ask to demonstrate .( I think I published it on PS 7 years ago)

1)Diamcalc has stereo mode, also it shows mono pictures for left and right eye.

5-8 years ago we had long PS discussions about "Death ring"( P(41-41.5), Cr35) and GIA, AGS cut grading systems.

I published ASET images for Left and Right eye, Explained Stereo Vision and fought against most PS members.( I received a lot of critics (and real personal attacks) specially from Infinity Diamonds )
So it has to be easy to find on PS.

2) 2 years ago we built Vibox with Stereo adapter , and may now compare mono and stereo movies for same real diamonds. It gave a lot of information and confirm previous statements had been done with Diamcalc .

Serg,
I guess some of those discussions were before my time here. I will make an effort to devote some time to reading them, and also to looking at your current research. My day job gets in the way many times, unfortunately.

To clarify specifically what I was asking if you could demonstrate - do you have a picture of a diamond showing ASET from slightly different angles-representing what each eye sees independently- and an image of what the brain sees (according to current understanding of binocular rivalry, dominant eye effect, etc) when both images are processed in stereo?

The glare image Garry posted is along those lines, although I have not been able to check it out in 3D yet. But for purposes of this particular discussion, it would be informative to see the differences in ASET images.

Bryan,
please find ASET's images for RBC Pavilion 41.4 Crown 34.5
1) classical ASET view( Cyclopean)
2) Right Eye
3) Left Eye

a)Human Binocular vision does not work for such contradictive images
b) ASET Code Light return and Light Leakage by high intensity( White, Green, Red). So it is just garbage for Binocular rivalry

but you may see:
1) There are not big leakage zone under table for both eyes in same time( but there is big leakage zone in cyclopean ASET)
2) of Big part Crown is green for left eye and red for right eye in same time( it is very important. it is one of reason why RBS is very good cut)
one diamond zone catch light from big angular range.

Very interesting Serg. I am not sure exactly what you mean by comments a and b, but comments 1 and 2 are clear.

One could then make the argument that diamonds with a mix of red and green, as seen by each eye independently, would have a promising ASET signature.

At what viewing distance does stereo vision start to give way to mono vision?

something between 700mm and 2000mm.

Btw, it is same threshold distance where diamond loose most part of Brilliancy ( and Fire , Scintillation become more important for diamond appearance)

see ASET's Left eye 500, 750, 1000, 1500mm(1.5m)

 

[Texas Leaguer]

At what viewing distance does stereo vision start to give way to mono vision?

something between 700mm and 2000mm.

Btw, it is same threshold distance where diamond loose most part of Brilliancy ( and Fire , Scintillation become more important for diamond appearance)

see ASET's Left eye 500, 750, 1000, 1500mm(1.5m)

Wow. Intuitively I would not imagine stereo vision would be operative at those distances.

Point well taken about fire and scintillation becoming more important aspects of diamond appearance at distance. That is intuitive, but I have never heard a scientific explanation of it before.

 

[OoohShiny]

This has been a very informative and interesting thread, thanks to all contributing to it!

I like the images illustrating the monocular/binocular vision discussion, they are very useful indeed

I am pretty good at those 'hidden images' in drawings that look like TV static so Garry's illustrative example has been easy to view in 3D - it's just a case of 'looking through' the screen till the two separate images combine into one If consumers were easily able to do this, providing such pictures from slightly different angles, akin to how your eyes would be seeing the stone, would provide excellent 'real life' illustrations of how the stone in question looks.

It could even be extended to video - e.g. record two videos from side-by-side positions, upload them into one file, then it could be played and they could be 'viewed live' in 3D using the same technique.

Voilá, no more issues with monocular photographs or video not being representative of how the stone looks in (binocular) real life (within the threshold limits detailed very usefully by Serg) and another tool for potential purchasers to assess stones with, alongside IdealScope, ASET, normal photographs...

 

[Texas Leaguer]

This has been a very informative and interesting thread, thanks to all contributing to it!

I like the images illustrating the monocular/binocular vision discussion, they are very useful indeed

I am pretty good at those 'hidden images' in drawings that look like TV static so Garry's illustrative example has been easy to view in 3D - it's just a case of 'looking through' the screen till the two separate images combine into one If consumers were easily able to do this, providing such pictures from slightly different angles, akin to how your eyes would be seeing the stone, would provide excellent 'real life' illustrations of how the stone in question looks.

It could even be extended to video - e.g. record two videos from side-by-side positions, upload them into one file, then it could be played and they could be 'viewed live' in 3D using the same technique.

Voilá, no more issues with monocular photographs or video not being representative of how the stone looks in (binocular) real life (within the threshold limits detailed very usefully by Serg) and another tool for potential purchasers to assess stones with, alongside IdealScope, ASET, normal photographs...

Agreed. I would not be at all surprised if we are getting a glimpse into the future of diamond imaging here. It is important to continue to evolve the tools (and proper interpretation of their results) as much as possible for a comprehensive understanding of what the diamond will look like in real life (under a wide range of viewing conditions and distances). It is all about adapting the internet to enable consumers to select from a vast number of possibilities efficiently and make the best possible buying decisions for their tastes and budgets.

To the extent that more consumers are able to do this better, the cutting community will adapt to this change by improving their cutting and creating new and better facet designs. And merchants will be offering a better menu of options.

Internet shopping is not going away. E-commerce is becoming more important with each passing day. Products that are unique and expensive, especially those with hard to communicate attributes such as diamond beauty, certainly lag behind commodity products in terms of numbers of people buying "sight unseen". But the only thing standing in the way are better communication tools.

 

[MelisendeDiamonds]

I took a few of my ideal cut radiants

Very interesting story from one of the pioneering families and contributors to what diamonds cuts are like today.

I have wondered over time about what the tradeoffs between weight, spread, brightness, and fire and how those change depending on how rectangular the rough is for the original radiant cut. The community would benefit, perhaps not in a thread with a title using a perjorative term like leakage but in another thread if you are willing. An open and transparent discussion on the pros and cons of the radiant and other cut cornered brilliant cut designs I would find interesting. I might be able to dig up some scans I could contribute.

But if a fancy could actually achieve the ASET image of a well cut round it would be a gorgeous diamond. In reality, for radiants at least, the ideal ASET (at least for the radiant that I consider ideal) looks nothing like the ideal ASET for a round and radiants with ASETs that approach that of a round look like crap.

Funny you should mention that but there is production of cut cornered square square brilliants in my backyard in the Canadian market, rough sourced and cut here in Canada. http://www.idealsquared.com/ and I think Pricescope has had threads about many different flavors of cut cornered squares of this type over the years with light return quite similar to Hearts and Arrows Rounds. "Look like crap" wouldn't be a description I would use for these stones, they are similar in cut precision and beauty to that of fine make rounds.

I always present my brand as providing choices within which the customer cannot make a mistake. But within that range the customer must make choices reflecting their own preferences - even my father and I often did not agree on which radiant we liked the best. When the ASET is presented that way it can be an excellent weeding out tool. Unfortunately a quick scan of posts here (admittedly not an exhaustive sampling) reveals that this is not always the case and that is where my concern lies.

Well perhaps we can address that in a new thread.

I think we may agree most radiant cuts are not designed with a primary emphasis on returning high angle light back to the viewer from edge to edge like a round brilliant. Other factors such as outline shape, spread, scintillation pattern, yield, and color are given more equal consideration in this cutting style.

 

[teobdl]

Very interesting. I'm glad the issue of distance was raised. The distances at which diamonds are viewed in real life by friends, family, and colleagues is closer to 500-1000mm and above (approx 18 inches to 1 yard away, in American). Typically, only the wearer will see her diamond ring at 250 mm.

 

[Garry H (Cut Nut)]

Very interesting. I'm glad the issue of distance was raised. The distances at which diamonds are viewed in real life by friends, family, and colleagues is closer to 500-1000mm and above (approx 18 inches to 1 yard away, in American). Typically, only the wearer will see her diamond ring at 250 mm.

At those distances a slightly shallower diamond looks way better than a slightly deep stone.
David do you know what the pavilon angle is where a shallow stone starts to have direct leakage?
There is only one shape I know that has the type of leakage that is typically described in the dumbed down things consumers are shown on most websites and instores.
https://www.google.com.au/search?hl...=en&q=diamond+shallow+ideal+deep+cut&tbm=isch
At a quick glance there is only one of those graphics that is accurate (apart from a few of mine).

 

[Garry H (Cut Nut)]

Garry- sometimes a bit of red is fine- other times it is indicating areas that go dark in a way I don't find attractve- net result is inconsistency on well cut stones with a lot of green.
I answered Serg question about fire a few pages back.

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Thank you Serg

Did you notice this exchange Garry? Do you disagree with Serg?
I undestand it may be difficult to have something you created questioned. But name calling reduces the discussion for all.

Re Fire - you wrote some things on page 3 David:
<<Serg- I have read and understand the AGS definition of fire. Thank you again Bryan for the link.
This can make communication between the experts on this thread possible. So WE know we're taking about the same thing.
But it changes nothing for consumers. A technical discussion of Ray tracing and stereoscopic vision will be lost on most consumers who just need a better way to use ASET images.
A lot more good points raised. I'll respond more completely later today.>>
That did not answer Sergey's question from near half way down page 2:
<<Dave,
1) what is Fire for you?
your Comments about Fire looks very strange for me. Please Clarify you Fire definition>>
And he asked again:
<<where is your Fire definition ? what is Fire in diamond for you?>>

Would you like me to start a specific new thread?

Re Leakage in diamonds, I agree to some extent with Sergey, infact in the critique on GIA's DiamondDock light box used to establish their cut grading system I have mentioned the stereo effect - and I have taken this on board with the new android HCA app (apple coming) for symmetrical diamonds. I also rigged up a very large ideal-scope with a stereo microscope years ago and examined several diamonds and yes, there is less leakage (which is impossible to photograph in a mono photo- even by laying two images over the top (I have tried it).
Where I disagree with Sergey:
1. is that when leaky round diamonds are dirty they suffer more from the dead dull look (I tested that at Vegas one year when Drena wore a shallow and slightly deep earring in each ear and after 2 weeks of no cleaning everyone preferred the shallower stone - even Peter Yantzer, who was shocked.
2. Sergey mentions that there is more scintillation sen from usual viewing distances - than fire (visible coloured flashes) or brilliance. Well if only part of the stone is able to return light there is obviously going to be less scintillation.

A shallower stone (that has less leakage) but more obstruction looks way better from a distance than a slightly deeper leaky stone. Try that too David.

 

[Serg]

Garry- sometimes a bit of red is fine- other times it is indicating areas that go dark in a way I don't find attractve- net result is inconsistency on well cut stones with a lot of green.
I answered Serg question about fire a few pages back.

ASET leakage does not equal to Human Stereo Vision leakage.
If ASET shows leakage it does not proof leakage in Stereo Vision.
It is big ASET weakness .

ASET image is not enough to do decision about Fancy cuts( neither positive nor negative)

Thank you Serg

Did you notice this exchange Garry? Do you disagree with Serg?
I undestand it may be difficult to have something you created questioned. But name calling reduces the discussion for all.

Re Fire - you wrote some things on page 3 David:
<<Serg- I have read and understand the AGS definition of fire. Thank you again Bryan for the link.
This can make communication between the experts on this thread possible. So WE know we're taking about the same thing.
But it changes nothing for consumers. A technical discussion of Ray tracing and stereoscopic vision will be lost on most consumers who just need a better way to use ASET images.
A lot more good points raised. I'll respond more completely later today.>>
That did not answer Sergey's question from near half way down page 2:
<<Dave,
1) what is Fire for you?
your Comments about Fire looks very strange for me. Please Clarify you Fire definition>>
And he asked again:
<<where is your Fire definition ? what is Fire in diamond for you?>>

Would you like me to start a specific new thread?

Re Leakage in diamonds, I agree to some extent with Sergey, infact in the critique on GIA's DiamondDock light box used to establish their cut grading system I have mentioned the stereo effect - and I have taken this on board with the new android HCA app (apple coming) for symmetrical diamonds. I also rigged up a very large ideal-scope with a stereo microscope years ago and examined several diamonds and yes, there is less leakage (which is impossible to photograph in a mono photo- even by laying two images over the top (I have tried it).
Where I disagree with Sergey:
1. is that when leaky round diamonds are dirty they suffer more from the dead dull look (I tested that at Vegas one year when Drena wore a shallow and slightly deep earring in each ear and after 2 weeks of no cleaning everyone preferred the shallower stone - even Peter Yantzer, who was shocked.
2. Sergey mentions that there is more scintillation sen from usual viewing distances - than fire (visible coloured flashes) or brilliance. Well if only part of the stone is able to return light there is obviously going to be less scintillation.

A shallower stone (that has less leakage) but more obstruction looks way better from a distance than a slightly deeper leaky stone. Try that too David.

Garry,
Please publish my statements with which you disagree.
1) Dirty( even slightly Dirty diamonds) are much worse than clean diamonds. you have to separate grades for clean and dirty diamonds.
bad performance of dirty P41.2Cr34.5 is not reason for downgrade this stone in compare with P40.7Cr34.5.
there is classical sales trick in shop: sales person do not clean enough GIA Ex and gives it( with report) to compare with clean fancy cut. of course fancy cut looks much better.
2) when I did such statement? in this thread I told that from long distance the Brilliance become less visible than Scintillation and Fire.
statement about Fire strongly depends from Light Environment. In some light you may see from long distances color flashes bigger than diamond

 

[Garry H (Cut Nut)]

Garry,
Please publish my statements with which you disagree.
1) Dirty( even slightly Dirty diamonds) are much worse than clean diamonds. you have to separate grades for clean and dirty diamonds.
bad performance of dirty P41.2Cr34.5 is not reason for downgrade this stone in compare with P40.7Cr34.5.
there is classical sales trick in shop: sales person do not clean enough GIA Ex and gives it( with report) to compare with clean fancy cut. of course fancy cut looks much better.
2) when I did such statement? in this thread I told that from long distance the Brilliance become less visible than Scintillation and Fire.
statement about Fire strongly depends from Light Environment. In some light you may see from long distances color flashes bigger than diamond

Hi Sergey, I disagree about the dirt on P41.2 C34.5, because for the test I preformed with Drena's earrings. Maybe someone can find that thread?
It would be good if we could devise a standard way to make pavilions equally dirty to the same way that people make them dirty. Then we could test it easily. But having cleaned and seen thousands of clients diamonds, I am confident that I am right.

Apologies - you did say fire and scintillation.
In a ring - surely the fire and scintillation on P41.2 C34.5 would be less than a P40.7Cr34.5 (of the same weight)?
The apparent size is definitely also smaller because of reduced light return from the edges of the stone (as well as the small diameter difference).

 

[Serg]

Garry,
Please publish my statements with which you disagree.
1) Dirty( even slightly Dirty diamonds) are much worse than clean diamonds. you have to separate grades for clean and dirty diamonds.
bad performance of dirty P41.2Cr34.5 is not reason for downgrade this stone in compare with P40.7Cr34.5.
there is classical sales trick in shop: sales person do not clean enough GIA Ex and gives it( with report) to compare with clean fancy cut. of course fancy cut looks much better.
2) when I did such statement? in this thread I told that from long distance the Brilliance become less visible than Scintillation and Fire.
statement about Fire strongly depends from Light Environment. In some light you may see from long distances color flashes bigger than diamond

Hi Sergey, I disagree about the dirt on P41.2 C34.5, because for the test I preformed with Drena's earrings. Maybe someone can find that thread?
It would be good if we could devise a standard way to make pavilions equally dirty to the same way that people make them dirty. Then we could test it easily. But having cleaned and seen thousands of clients diamonds, I am confident that I am right.

Apologies - you did say fire and scintillation.
In a ring - surely the fire and scintillation on P41.2 C34.5 would be less than a P40.7Cr34.5 (of the same weight)?
The apparent size is definitely also smaller because of reduced light return from the edges of the stone (as well as the small diameter difference).

it is not good idea to mix "Dirty durability" and Optical performance .( your statement about Death Ring in ASET images are very misleading)
it wise to give independent grades for
Optical performance( for clean diamonds)
Craftsmanship
Optical symmetry
Spread
Durability
Dirty durability

and give to Consumer opportunity for themselves choice .
if you compare orange with apple it just mislead consumer.
If you want grade Dirty Durability by ASET images( what may be wrong method) then You have to publish ASET images for clean and dirty diamonds with reference ASET images for P40.75Cr34.5( clean and dirty in same level and method)
we discussed its 5-7 years ago? But you never published ASET images for dirty reference diamonds.

also ASET images does not work for earring diamonds.

 

[Serg]

Garry,
Please publish my statements with which you disagree.
1) Dirty( even slightly Dirty diamonds) are much worse than clean diamonds. you have to separate grades for clean and dirty diamonds.
bad performance of dirty P41.2Cr34.5 is not reason for downgrade this stone in compare with P40.7Cr34.5.
there is classical sales trick in shop: sales person do not clean enough GIA Ex and gives it( with report) to compare with clean fancy cut. of course fancy cut looks much better.
2) when I did such statement? in this thread I told that from long distance the Brilliance become less visible than Scintillation and Fire.
statement about Fire strongly depends from Light Environment. In some light you may see from long distances color flashes bigger than diamond

In a ring - surely the fire and scintillation on P41.2 C34.5 would be less than a P40.7Cr34.5 (of the same weight)?
The apparent size is definitely also smaller because of reduced light return from the edges of the stone (as well as the small diameter difference).

1) May be ! P41.2CR34.5 has even more Fire than P40.7Cr34.5. I will check it with our last Fire metrics and publish here.
I checked many real P41-P41.5 in real light and did not see anything wrong for may Taste and eyes.
2) is it joke? did you check difference in spread, microns? Please stop do misleading statements without checking real values.
please compare this spread difference with spread variation for ASGO diamonds( at least due girdle thickness variation)

I sure you see neither difference in light return nor in spread by your eyes for these 2 diamonds( with or without loupe ).
but may be P41.2 gives more Fire than Pavilion 40.75 and this difference in visible.
I think 6-8 years ago I published raytracing images which support it.
pavilion VF;s has bigger angle in diamond with P41.2, so dispersion angle is bigger too( but Brightness is similar in stereo vision)

 

[OoohShiny]

also ASET images does not work for earring diamonds.

Is this because they are worn 'vertical' and not 'horizontal', so will never have strong light hit them directly from 'above' (i.e. perpendicular to) their table, which is how ASET works and assumes diamonds will be seen?

Would angled ASET images (similar to those already posted) be better assessment tools than 'normal' ASET images?

 

[Serg]

also ASET images does not work for earring diamonds.

Is this because they are worn 'vertical' and not 'horizontal', so will never have strong light hit them directly from 'above' (i.e. perpendicular to) their table, which is how ASET works and assumes diamonds will be seen?

Would angled ASET images (similar to those already posted) be better assessment tools than 'normal' ASET images?

1) Yes, because a lady wear its vertically
2) No. it is necessary develop new structure light instead just tilt diamond

 

[yasssss]

Hi experts! so I know you can tell if a stone has light leakage from an aset image, but how do you tell in real life with a princess?

If you put something red underneath it you will see which areas of the crown appear red and are drawing light from the pavilion or leaking light out the bottom.

I actually feel like there is a not a lot of light leakage in my stone at all because in most lighting it sparkles from corner to corner, but sometimes in photos it looks dark but that may be the reflection?

Yes indeed, the camera has to get close for focus and magnification and the dark lense or body can be reflected in the diamond making the diamond look dark. This is very common in macro photographs of the brightest diamonds that gather light primarily from high angles.

i was just wondering if there were photos or something that showed examples of leakage.

See that ring of skin color underneath the table that is a pretty dramatic case of leakage.

I love my glittery stone and get compliments on how sparkly it is all the time, all this pricescope reading has me wondering though how this looks like in a real life perspective

The best way would be to compare it to others in the same lighting. Go to stores and compare to other princess cuts and try to find fine makes and look at them in many different lighting environments. I don't think this requires an ASET scope, you aren't comparing blindly over the internet your eyes in your lighting are the best judge.

this is incredibly helpful!! thank you!!! I will definitely go and compare my princess with others. it sounds like fun too! I've only done that once at a Tiffany's with one of their ~2 ct princess solitaires and mine was giving off more flash! (obviously both were sparkly under the tiffanys ligthing, but mine was so glittery even the saleswoman commented) yay!

and i'll stick some red fabric under the diamond and will report back! thanks again!

 

[OoohShiny]

also ASET images does not work for earring diamonds.

Is this because they are worn 'vertical' and not 'horizontal', so will never have strong light hit them directly from 'above' (i.e. perpendicular to) their table, which is how ASET works and assumes diamonds will be seen?

Would angled ASET images (similar to those already posted) be better assessment tools than 'normal' ASET images?

1) Yes, because a lady wear its vertically
2) No. it is necessary develop new structure light instead just tilt diamond

Thank you for your reply, Serg

Going from 2), and the fact that any new assessment will take time to develop, are there any particular techniques to use now to assess earring diamonds? Or are there certain proportions that work better?