Discussion of aset in simple terms

[Rockdiamond]

HI All,
The goal if this thread is to simplify explanations of aset interpretations.
I'm not a scientist, nor do I have plans to become one.
I also don't believe consumers need to become ray tracing specialists to buy well cut diamonds. The appreciation of a well cut diamond is so very simple that the tools we use on a daily basis also need to have simple explanations to be of value to consumers as a group IMO

What I am asking for is a manner of interpreting aset images which is easily understandable by all readers not wishing, or able to understand the highly technical aspects.
If it's a simple tool, it's value must include ways of using it so a majority of consumers, as well as dealers, can understand.

My suggestion: I will procure stones specifically for this thread, present aset photos, as well as actual photos, I will then be able to correlate the information with what I see, and report back.
I'll also be glad to have srn files generated, if that will help.

I apologize if this has all been covered before, but we're here now, and this is a perfect time to start.
This is an aset of a stone that I felt had a slightly "blotchy" appearance.
It was still pretty nice IRL, but I passed on it


How would those more familiar with interpreting aset describe this stone?

 

[ChunkyCushionLover]

RD,

Before we move to examples, an dicussion of the terms being used to evaluate the diamonds are important.

The most important one ASET is measuring is a diamond's potential brightness.

I define brightness using AGSL's definition:

For understanding the illumination appearance of a gem it is useful to think of a gem’s facets and their optical projections,
the virtual facets, as a collection of tiny prisms that direct light to an observer’s eyes. Thus brilliance(brightness) is defined as the percentage by area of such tiny prisms that can direct light to the observer’s eyes.

Do you agree to AGSL's definition of brightness for the purpose of this thread and any further discussion(s) with respect to ASET?

 

[Garry H (Cut Nut)]

Not a lot happening in that stone that is great David.

Here is some graphic info on another stone you posted that shows where the stone is gathering its light. Hope it helps.

(CCL please dont drag away from the topic)

 

[Rockdiamond]

thanks for responding ccl
Breaking it down into simple terms may really allow me ( and others) a better understanding.

I can agree that in any given instant, how bright a diamond looks is dependent on how many of the facets, or virtual facets are directing the light hitting them to the observer's eyes.
Part of what has been my objection to aset is essentially what others might object to in a photo that does not block the pavilion.
They both show an instant in time- but in real life the diamond is never completely stationary in relation to the light, or the observer's eye.

The questions I have involve how the particular instant shown by the aset relates to real life. I spent time looking at the stone in the aset

If someone posted that aset photo, how would you analyze it?

The aset confirms that the stone is a four main modified cushion. DO you concur?

 

[Rockdiamond]

Not a lot happening in that stone that is great David.

Here is some graphic info on another stone you posted that shows where the stone is gathering its light. Hope it helps.

(CCL please dont drag away from the topic)

Garry- I'm asking straight out- as in the title- aset for dummies.

I don't see any real life significance in any of the images, except the aset simulation.
I promise, I'm not trying to give anyone a hard time, I don't understand what three of them represent.
The circle seems to represent an aset .
The ray tracing image does not give me any meaningful info- which is why I'm asking for simple explanations.
If that one ray of light traveled in that direction how is that relevant when there are probably millions of rays of light hitting the stone?

What does the image on the top left represent?

 

[Garry H (Cut Nut)]

Not a lot happening in that stone that is great David.

Here is some graphic info on another stone you posted that shows where the stone is gathering its light. Hope it helps.

(CCL please dont drag away from the topic)

Garry- I'm asking straight out- as in the title- aset for dummies.

I don't see any real life significance in any of the images, except the aset simulation.
I promise, I'm not trying to give anyone a hard time, I don't understand what three of them represent.
The circle seems to represent an aset .
The ray tracing image does not give me any meaningful info- which is why I'm asking for simple explanations.
If that one ray of light traveled in that direction how is that relevant when there are probably millions of rays of light hitting the stone?

What does the image on the top left represent?

The circle shows an ASET model for dummies - the diamond would be in the middle facing up to the top.
The ray trace shows that some beams come from many diffrent places, and this is especially true for crushed ice appearance stones.

The image on the top left can be understood from this http://www.cutstudy.com/cut/english/comp/scint1.htm very old MSU OctoNus tool (which will only work in IE and not FireFox).

Regarding stones moving - it is a very good idea to hold the stone in tweezers and rock it while looking with ASET

 

[ChunkyCushionLover]

thanks for responding ccl
Breaking it down into simple terms may really allow me ( and others) a better understanding.

I can agree that in any given instant, how bright a diamond looks is dependent on how many of the facets, or virtual facets are directing the light hitting them to the observer's eyes.

Okay so we are in agreement with the definition of brightness that is a good start.

Part of what has been my objection to aset is essentially what others might object to in a photo that does not block the pavilion.
They both show an instant in time- but in real life the diamond is never completely stationary in relation to the light, or the observer's eye.

Whether its an ASET photograph (static) or in motion(a video) the tool still does the same thing. Instead of posting static image examples you could provide a ASET video instead or take .srn scans and accept the generated ASET video as similar enough to the video taken through the scope.

I did this simulated video before http://www.youtube.com/watch?v=4UuzoMQl6Oc to show what the Radiant you had scanned would look like through the ASET scope when you were tilting the diamond slightly.

Do you agree the ASET video I posted is a fair representation of what that stone would look like if you looked at it through your hand held while tilting (5 degrees up down, 3 degrees left right)?

Gary did this kind of thing for a princess cut here http://www.ideal-scope.com/1.using_ASET_scope.asp
Scroll down to Movie of Daylight ASET.

Any questions or objection to this methodology?

 

[Karl_K]

David,
That format would not be scientifically valid and there are better ways.
You are not an impartial observer, your well known likes and dislikes would make any impressions invalid.
For such a format to be valid a panel of impartial viewers would have to be selected and have the diamond available.
That is the reason the GIA cut grade is a joke so your not alone.

 

[Rockdiamond]

David,
That format would not be scientifically valid and there are better ways.
You are not an impartial observer, your well known likes and dislikes would make any impressions invalid.
For such a format to be valid a panel of impartial viewers would have to be selected and have the diamond available.
That is the reason the GIA cut grade is a joke so your not alone.

Karl- I agree with your first point- that this is not a scientifically valid exercise.
It is more an observational one. I would make the point that given that who I am is known, my views can be considered in context- therefore, having some value.
There also may very well be better ways.

I disagree that the GIA cut grade is a joke. Which is an admittedly convenient position to take, as it basically validates a lot of points I raise that draw flack.
If we can agree that GIA's human observation tests are the most complete that exist in the study of the cut of round diamonds.

Some of the diamonds that are included in the "EX" cut grade that won't be considered the best cut by some observers.
Also possible is VG graded stones getting better scores on human observations compared to EX.
In that regard, maybe the cut grade is a joke- but we'd have to disqualify all cut grades on that basis.

If you want to look at diamonds in reality, using examples we can find fault with can be of great value in a basic course on how to interpret them impartially.
Remember, your tastes also come into play Karl- as do Garrys.

The aset I posted above is a good example.
There are aspects to that diamond that will be identified as negative.
Garry can point out the areas where the aset indicates leakage.
The green area at the top right was one part that I felt correlated to a "spoltchy" region of the stone IRL for example.
In that sense, I can see how green might not be something you want.
IF, what you want is even crushed ice.
But can we agree that the green area around 2:00 is a darker area in real life potentially?

 

[diagem]

But can we agree that the green area around 2:00 is a darker area in real life potentially?

I believe the stone is a bit tilted?

 

[ChunkyCushionLover]

David,
I disagree that the GIA cut grade is a joke. Which is an admittedly convenient position to take, as it basically validates a lot of points I raise that draw flack.
If we can agree that GIA's human observation tests are the most complete that exist in the study of the cut of round diamonds.

But can we agree that the green area around 2:00 is a darker area in real life potentially?

RD,

I am trying my best to reach common ground here, the GIA cut grading arguments are both off topic and really aren't in fine enough detail to be respectful of either side of that research and application. We could do an entire thread on that issue alone in future if you and Karl would like.

Before we get into the solid green area (which I wouldn't interpret as you have) please back up to this post post above where I am attempting to reach a reasonable framework for interpretation of the images.

https://www.pricescope.com/communit...in-simple-terms.150589/#post-2730646#p2730646

Is there room for agreement and common ground on the framework and general methodology before we debate the interpretation of one image and stone?

 

[Rockdiamond]

thanks for responding ccl
Breaking it down into simple terms may really allow me ( and others) a better understanding.

I can agree that in any given instant, how bright a diamond looks is dependent on how many of the facets, or virtual facets are directing the light hitting them to the observer's eyes.

Okay so we are in agreement with the definition of brightness that is a good start.

Part of what has been my objection to aset is essentially what others might object to in a photo that does not block the pavilion.
They both show an instant in time- but in real life the diamond is never completely stationary in relation to the light, or the observer's eye.

Whether its an ASET photograph (static) or in motion(a video) the tool still does the same thing. Instead of posting static image examples you could provide a ASET video instead or take .srn scans and accept the generated ASET video as similar enough to the video taken through the scope.
I have not found a way to photograph a diamond aset image other than using the light- which places the diamond in a stationary position- I'd have no idea how to take a video allowing rocking

I did this simulated video before http://www.youtube.com/watch?v=4UuzoMQl6Oc to show what the Radiant you had scanned would look like through the ASET scope when you were tilting the diamond slightly.
All due respect, but I don;t feel that the simulated diamond portrayal matched what my eyes see in real life. In terms of the aset- it also looks different from what I see if the stone is on the light, and viewed through the aset

Do you agree the ASET video I posted is a fair representation of what that stone would look like if you looked at it through your hand held while tilting (5 degrees up down, 3 degrees left right)?

Gary did this kind of thing for a princess cut here http://www.ideal-scope.com/1.using_ASET_scope.asp
Scroll down to Movie of Daylight ASET.

Any questions or objection to this methodology?

Sorry for the slow reply ccl

 

[Rockdiamond]

But can we agree that the green area around 2:00 is a darker area in real life potentially?

I believe the stone is a bit tilted?

Possible Yoram... I do find the aspect of getting the stone perfectly level difficult.
Even so, I can correlate that area with something I see in real life.

 

[ChunkyCushionLover]

thanks for responding ccl
Breaking it down into simple terms may really allow me ( and others) a better understanding.

I can agree that in any given instant, how bright a diamond looks is dependent on how many of the facets, or virtual facets are directing the light hitting them to the observer's eyes.

Okay so we are in agreement with the definition of brightness that is a good start.

Part of what has been my objection to aset is essentially what others might object to in a photo that does not block the pavilion.
They both show an instant in time- but in real life the diamond is never completely stationary in relation to the light, or the observer's eye.

Whether its an ASET photograph (static) or in motion(a video) the tool still does the same thing. Instead of posting static image examples you could provide a ASET video instead or take .srn scans and accept the generated ASET video as similar enough to the video taken through the scope.
I have not found a way to photograph a diamond aset image other than using the light- which places the diamond in a stationary position- I'd have no idea how to take a video allowing rocking

I did this simulated video before http://www.youtube.com/watch?v=4UuzoMQl6Oc to show what the Radiant you had scanned would look like through the ASET scope when you were tilting the diamond slightly.
All due respect, but I don;t feel that the simulated diamond portrayal matched what my eyes see in real life. In terms of the aset- it also looks different from what I see if the stone is on the light, and viewed through the aset

Do you agree the ASET video I posted is a fair representation of what that stone would look like if you looked at it through your hand held while tilting (5 degrees up down, 3 degrees left right)?

Gary did this kind of thing for a princess cut here http://www.ideal-scope.com/1.using_ASET_scope.asp
Scroll down to Movie of Daylight ASET.

Any questions or objection to this methodology?

Sorry for the slow reply ccl

Where is the faceup image of ORC you took through your handheld (Did you ever post it?) link me please.

I'm going to try to match it up to the simulated one I did in the Crushed Ice thread https://www.pricescope.com/communit...ions-bad.148696/page-11#post-2697946#p2697946

Does the simulated ASET image match the photographed ASET image for that ORC? Why or why not?

 

[Rockdiamond]

I believe this is the one ccl- I'm not sure so I can re-take the photo if need be

 

[ChunkyCushionLover]

Please retake it without tilting the diamond. Use Garry's focus trick, focus a third of the way below the table. It really important you get sharp resolution of different colored virtual facets.

Still no color correction of the white balance have you figured that out?

I can work with this image though even given its limitations.

 

[ChunkyCushionLover]

Do you agree this is a pretty good match?

 

[Rockdiamond]

Remember ccl- I'm involved in this exercise to increase my knowledge of practical usage of aset
Therefore, answering that question will bring up other questions.
I can see similarity. The shape is identical, for example.
Am I wrong to expect to see identical facets, behaving the same way in either photo?

 

[ChunkyCushionLover]

Remember ccl- I'm involved in this exercise to increase my knowledge of practical usage of aset
Therefore, answering that question will bring up other questions.
I can see similarity. The shape is identical, for example.
Am I wrong to expect to see identical facets, behaving the same way in either photo?

RD,

For the purposes of comparison the red and blue are in the same places as is the white and green. This is good enough to make the same general brightness assessment from both images and arrive at the same conclusions. We do not need to count pixel by pixel or facet by facet, each color to make a general interpretation of where this diamond receives light in each area (under the table, edges etc).

Slight tilt of the stone(even less than one degree), the stone is not centred in your photograph, strong backlight washing out the weak green, poor white balance, all contribute to the differences.

I will ask you to accept the simulated image as close enough to photographed image. If not we cannot move on until you take better ASET images. Garry knows all about this and can advise you on a full setup like GOG or WF have done.

Will you accept simulated ASET as close enough?

 

[Rockdiamond]

Let me have another try- that was one of the first photos I took.

I just spent a while looking at an square emerald using aset and had a bit of a "duh" moment.
In that regard, I feel more comfortable now with step cuts, and how the information relates to real life.

Cushions, and radiants not yet.

 

[Garry H (Cut Nut)]

To make a movie with ASET blue tac'ed to the lens (what is the US product name??? for 3M non greasy plasticine for sticking posters to the wall?) and then you can rock the stone in the tweezers.

CCL to match David's ASET photo you may need to change the ASET lighting angles >options>advance> ligthing configuration.
It is easy to change the angles a bit by being too close or 2 far away, and as we can see it is slightly out of focus.
But the color balance is pretty good now.

 

[Rockdiamond]

How's this?

 

[ChunkyCushionLover]

Focus is better, diamond was tilted a bit, I had to tilt up and to the right to get a better match.



Is this close enough for you now? I don't think its worth worrying about so many simulation variables to try to get it closer to a match.

 

[ChunkyCushionLover]

Last one even closer.

 

[Rockdiamond]

That is pretty close ccl, agreed.
For me, the next step is correlating that to real life experience.
Today, working with a step cut, I got a much better insight into some of what the aset can do.
I could manually find the facets that allowed me to see my finger behind ( using a loupe) and correlate that to white on the aset.

It was like a little light bulb finally turned on.

But looking at this aset- and the actual diamond, I'm having trouble finding a correlation. For example, there's areas of green and red that have almost zig zag pattern on the aset.
In real life those are small virtual facets- but the adjacent areas are far closer in color.
Maybe the micro facet lighting up ( red on the aset) is superbright- but the micro facet reflection next to it ( green on the aset) is a very close gradient of silver. Not a lot of contrast- almost impossible to see- and contributes to the crushed ice effect
Let's , for the purposes of this discussion say that in real life, I find this diamond to be what Garry is describing below.

Good crushed ice diamonds appear to have an overal very even array of very small flashes that 'roll' as the stone is rocked from side to side. There should be no easily identified larger dark zones (which can be most commonly the result of head obstruction, or leakage). All the flashes should be very small resuting in a pinfire effect.
The cause of the appearance of an exceptionally large number of facets is the many internal reflections which split the observed facet structure at each internal reflection.
The contrast between bright and dark areas is often contributed to positively by very small zones of leakage.....

ccl, you had previously expressed preference for a different style of cut cornered square brilliant. Could we compare them?

 

[Garry H (Cut Nut)]

Last one even closer.

Very good CCL

1. David if you pull the scope away from the stone you will see some blue parts turn red, and some red turn green. These are the border line parts. CCL if you want you can get closer buy matching that - this photo has the scope a little far away compared to DC I think.

2. CCL you can raise the number of interactions and get a lot more crushed ice definition. And any errors in the scan will then also show up more.

 

[ChunkyCushionLover]

Last one even closer.

Very good CCL

1. David if you pull the scope away from the stone you will see some blue parts turn red, and some red turn green. These are the border line parts. CCL if you want you can get closer buy matching that - this photo has the scope a little far away compared to DC I think.

2. CCL you can raise the number of interactions and get a lot more crushed ice definition. And any errors in the scan will then also show up more.

1) For 1 I already had to do this to show properly some of the blue regions changing R distance from source I beleive simulates moving the scope away, as does changing the cone of radius making it smaller as well. Right?

2) How do you change number of interactions?

 

[ChunkyCushionLover]

That is pretty close ccl, agreed.

1) We agreed the ASET is measuring brightness as defined but the total area that can appear illuminated to the observer at any one time.
2) We also agree simulated and photographed ASET images have very good correlation even for "crushed ice" diamonds. Thus in future you can get .srn files and a simulated ASET video will be able to provide video where your setup does not permit.

ccl, you had previously expressed preference for a different style of cut cornered square brilliant. Could we compare them?

For comparing brightness, I have posted this video, it was one of the first I did so not the greatest in framerate or compression quality. It does show what the ORC looks like in comparison to the bright radiant I was talking about both Lightbox and ASET30 lighting included one above the other.

The ORC has much faster scintillation but also has significantly more dark regions at any time which is consistant with the ASET images as well.

http://www.vimeo.com/14985843

I also did this one just now, the top is lightbox lighting again with a 20 degree up/down tilt. The bottom is lighting from Gary's Canterbury store, and where the observer's head is blocking most of the overhead lighting.

http://www.vimeo.com/15653513

 

[Garry H (Cut Nut)]

Last one even closer.

Very good CCL

1. David if you pull the scope away from the stone you will see some blue parts turn red, and some red turn green. These are the border line parts. CCL if you want you can get closer buy matching that - this photo has the scope a little far away compared to DC I think.

2. CCL you can raise the number of interactions and get a lot more crushed ice definition. And any errors in the scan will then also show up more.

1) For 1 I already had to do this to show properly some of the blue regions changing R distance from source I beleive simulates moving the scope away, as does changing the cone of radius making it smaller as well. Right?

2) How do you change number of interactions?

Open simulation Parameters, unclick fast and on the right drop down select highest. Then open the Custom cut and I raised from 5 to 10. It will take a long time to render - maybe 5 times a well cut round because of the longer rays.
But you could make a much more realistic movie (over night CCL).

BTW we will never get a really good match unless you send stones to rhino to be scanned David because the Sarin scan is pretty hopeless

 

[Rockdiamond]

But looking at this aset- and the actual diamond, I'm having trouble finding a correlation. For example, there's areas of green and red that have almost zig zag pattern on the aset.
In real life those are small virtual facets- but the adjacent areas are far closer in color.
Maybe the micro facet lighting up ( red on the aset) is superbright- but the micro facet reflection next to it ( green on the aset) is a very close gradient of silver. Not a lot of contrast- almost impossible to see- and contributes to the crushed ice effect

From my perspective, the fact that the simulation match the photo I took is not the issue.
I have the stone, and the aset- I don't see how we can correlate adacent areas that show stark contrast on the aset, but very slight contrast in the diamond in real life