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What is the difference between Cut Grading and Cut Rejection

Re: What is the difference between Cut Grading and Cut Rejec

Garry H (Cut Nut) said:
I have cross checked the data, because I have a stereo lap top and make 3D movies to check what seem like anomalies. Invariably there seems to be an issue of stones with good brightness washing out fire. (Some here will know I have long thought brightness is the enemy of fire).


I have no idea what you are referring to please reference some CA/PA combinations and cut and paste a diagram to show what you mean.
How are you measuring fire and showing it is being washed out? Dispersion statistics diagram?
 
Re: What is the difference between Cut Grading and Cut Rejec

"1) You haven't explained or even defended your model. If you have show me the published article, or poster presentation if not in a journal on your web site! Nothing related to this in the last 10 years in your cut study link."

Draco,
1)It is your choice how you prefer to receive knowledge .
seems you choice is different from choice of autores http://www.agslab.com/spie/spie_lo_res.pdf
Did you really study this article, references in this article?

btw. Did You think why AGS researches publish this article in "Optical Engineering"?
Do you know any article in G&G about cut study which had not been written by GIA researches ?

Sorry, that we did not to publish our Cut Study works in magazines like "Optical Engineering" just to receive publication and say you we have Peer review article. Sorry, it was not necessary fo us. If you are very interesting but according your internal rules you can not read articles on web sites then we do our best to write article in Peer review magazine .

Please send full list of good enough for your Peer Review magazines which are interesting for people from diamond industry.
What do they read?
What do you read regularly ?

2) Diamcalc has not metrics Neither for Brilliancy nor for Fire. It has several rejections tools as LR, ETAS, Dispersion Statistics Diagram , Darkzones and 20 others.
because its are just rejection tools to decrease time for cut developers we do not need give detail description .
Such description will not help to develop better cuts.
 
Re: What is the difference between Cut Grading and Cut Rejec

Draco|1368107016|3443364 said:
serg said:
similar system could be part of Cut Performance grade system
Open grading system which account Real consumer experience ( for example you can not publish comments in booking.com if you did not stay this hotel), help a lot for consumers and for good business:
1) If you want open new hotel , you can study in advance that consumers prefer and respect
2) If you do good service for clients then a lot of consumers will know it. If you do something new and your clients like it then you receive very good promotion.

GIA tried this in their cut grading of rounds. it was an extensive study acceptable by the majority of trade today but judging by the comments on here (especially by niche market consumers and trade) it will never be good enough for some. Subjective grading systems no matter how many data points collected are still just that subjective and will be readily dismissed by those who have a different subjective opinion.

Garry in HCA allows more shallow diamond combinations, GIA study and subsequent cut grading allows more steep deep combinations, both are biased and subjective. Even if either conclusion was reached by polling the majority opinion of a million consumers that opinion may not be relevant to one consumer trying to make a decision on one stone.

I don't think labs should give their subjective opinion to consumers, trade almost always does this, most are always selling whether consciously and intentionally or not.

Objective is fine, present the technical information, provide images and video, explain what it means and then let the consumer make up their own mind and form their own subjective conclusions.

Draco,

An objective system that has low or unknown correlation with subjective human observation is less helpful for consumer than a subjective system which has good correlation with Human observation.
.
Best grading system for consumer is Objective system with good and proven correlation with human observation

It is very easy to build many different Objective systems if you do not mind about good correlation between Objective system and Subjective Human observation.
for my private experience Objective systems based on static and mono images have too low correlation with Human observations.
It is not very difficult to calculate flashes, them brightness , saturation, area , numbers... , probability of flashes, o dispersion( It is not easy task, but not so difficult for skillful team)
the main problem is to model Human brain reaction , to account stereo vision, temporal brain reaction , and many others "Subjective factors" which create Brilliancy and Fire phenomenas in your brain and give positive signals to your Brains. Just information about number colorful pixels is faraway from model of Human reaction.
Brilliancy is not "Objective " phenomena . Brilliancy is result of Human vision system limitations (temporal and brightness limitations) compensated very complex Human brain work.
It is easy to write many reasonable metrics based on dispersion, brightness, area, number but without:
accounting the subjectivism of Human vision they have low value.

Best way to check validity of grading system is use it to develop new beautiful cuts.
 
Re: What is the difference between Cut Grading and Cut Rejec

Serg said:
Best way to check validity of grading system is use it to develop new beautiful cuts.

Serg,

I'd rather not focus on credentials or publications as you are in the private sphere so I really don't see anything publicly published from you in a decade. The newest articles from your cut group related to the subject still say "new" on the cutstudy website and they were posted in 2004.

I did come across this though:

https://www.pricescope.com/communit...nal-story.157859/page-8#post-2881039#p2881039

Serg said:

I believe what machine Fire measurement. :
1) is possible
3) will be done correctly* in next few years( both types:direct and indirect )
* it means what such metrics will have very good correlation with human fire perception .
what we are doing right now.
1) we design and optimize cushions cuts according our Fire metrics ( we have goal to receive cut with similar brightness as round cut(AGS0) but with higher Fire
2) Cut it
3) compare fire of these cuts with round cut in different light environments with goal to find difference between our Fire metrics and Human Fire perception . if we found sum difference we change our fire metrics and repeat step 1. after each iteration we see bigger and bigger correlation between Fire Prediction and Human Fire perception .


Would you mind explaining what fire metric you are using (in brief) and how it is being used to design those cushions listed in the MSS stone list, the ones where the published .gem files are not downloadable.
 
Re: What is the difference between Cut Grading and Cut Rejec

Garry H (Cut Nut)|1368144966|3443684 said:
I have been using DiamCalc Pro to redo the HCA data for the new HCA app and in many cases I have mono and stereo metrics (with size and intensity weighted options) and I can tell you that there are some considerable differences. I have cross checked the data, because I have a stereo lap top and make 3D movies to check what seem like anomalies. Invariably there seems to be an issue of stones with good brightness washing out fire. (Some here will know I have long thought brightness is the enemy of fire).

You are welcome for the participation Garry, but you may take it back after I ask the following. :naughty:

Are you going to scrap the redone HCA data given Serg's reservations about the validity of your new conclusions based on fire metrics?
Are you going to remove your bias for shallow pavilion diamonds in the new version?
 
Re: What is the difference between Cut Grading and Cut Rejec

Draco|1368308044|3445067 said:
Garry H (Cut Nut)|1368144966|3443684 said:
I have been using DiamCalc Pro to redo the HCA data for the new HCA app and in many cases I have mono and stereo metrics (with size and intensity weighted options) and I can tell you that there are some considerable differences. I have cross checked the data, because I have a stereo lap top and make 3D movies to check what seem like anomalies. Invariably there seems to be an issue of stones with good brightness washing out fire. (Some here will know I have long thought brightness is the enemy of fire).

You are welcome for the participation Garry, but you may take it back after I ask the following. :naughty:

Are you going to scrap the redone HCA data given Serg's reservations about the validity of your new conclusions based on fire metrics?
Are you going to remove your bias for shallow pavilion diamonds in the new version?

Draco I will replace the data. My techniques are based on my judgement and if people want to use those judgments then they have been free to do so for more than a decade. I published the original data at www.diamond-cut.com.au and in the granted USA patent, so I suppose that is some level of publication that you may approve of. My approach just so happened to predate the AGS and GIA systems and most people could easily see a correlation.
In my longstanding relationship and association with Sergey, Yuri Shelemintiev and Janak Mistry I have learned a lot more and more tools have become available to me. HCA is my opinion, and it is no surprise that Sergey does not think it is a solution to the issues we are discussing here - its just one epxerts view of round diamond performance with a system that is all but impossible to apply to almost all fancy cuts (as GIA also learned since they went down the same road, a matter that the patent office is still trying to resolve).

What Sergey is working on, and in some small part I am helping with, is a much bigger thing than HCA.

But in an attempt to answer your question - there is a relevant discussion in this article from the IDCC that we four hosted in Moscow in 2004. http://www.gemology.ru/cut/english/conferens-article/2.htm The coloured chart is very relevant and is close to the approach that I took and continue to take with HCA - the only big weakness is its just me - it is easily possible you would get different results from surbveying different experts and consumers. GIA attempted this in part with the DiamondDock light box (which in our view provided illumination that favoured deeper steeper RBC's than my preference. But it is likely I will meet them half way with my new data set because it is using more stereoscopic DiamCalc data.

BTW I will be in Vegas for JCK if you would like to enjoy the discussion over a glass of red or a belgian beer Draco?
 
Re: What is the difference between Cut Grading and Cut Rejec

Draco|1368307734|3445062 said:
Serg said:
Best way to check validity of grading system is use it to develop new beautiful cuts.

Serg,

I'd rather not focus on credentials or publications as you are in the private sphere so I really don't see anything publicly published from you in a decade. The newest articles from your cut group related to the subject still say "new" on the cutstudy website and they were posted in 2004.

I did come across this though:

https://www.pricescope.com/communit...nal-story.157859/page-8#post-2881039#p2881039

Serg said:

I believe what machine Fire measurement. :
1) is possible
3) will be done correctly* in next few years( both types:direct and indirect )
* it means what such metrics will have very good correlation with human fire perception .
what we are doing right now.
1) we design and optimize cushions cuts according our Fire metrics ( we have goal to receive cut with similar brightness as round cut(AGS0) but with higher Fire
2) Cut it
3) compare fire of these cuts with round cut in different light environments with goal to find difference between our Fire metrics and Human Fire perception . if we found sum difference we change our fire metrics and repeat step 1. after each iteration we see bigger and bigger correlation between Fire Prediction and Human Fire perception .


Would you mind explaining what fire metric you are using (in brief) and how it is being used to design those cushions listed in the MSS stone list, the ones where the published .gem files are not downloadable.



There are several reasons:
1) In last years we saw Many patents from different companies about Cut Light performances using diamond 3D models. There is big risk that somebody will use our new internet publications to write new patents which may block our future business . We happy share knowledge with other researches on interchange base but we prefer avoid patents from other companies about our technologies and ideas. It was not interesting for to publish our intermediate results in 2005-2010 .
Seems that you are not consumer and you have connection with Light performance research so you have be aware about risk for business from Patent system and such patents. Word are not perfect and many companies use disadvantages of Patent system in aggressive way.
2) It was necessary to develop several new technologies To create next step in Light Performance research.
a. Stereo for photoreal Diamcalc images and for photos of real diamond
b. System to create movies from real diamond with high level repeatability ( we need receive same metric results for real movies and for DC movies from same diamond)
c. metrics based on real movies which work with real movies and DC movies
d. new cutting technologies to produce Fancy cuts according Diamcalc design( for bruiting ( shaping) and faceting . infrared or green Laser shaping is not good enough for several reasons)
e. develop and produce fancy cuts with at least similar light performance as in best round cut
3) we spent time to develop technology to improve performance of Fancy color diamond . you can find much more beautiful fancy cuts now( even from M color)http://www.octonus.com/oct/projects/fancycolor.phtml
4) it is necessary to create system to collect and understand consumer decisions about Diamond Beauty Performance ( we are developing such system but did not finish it yet)
5) Explanations about our new technologies we are writing now either in our Patents or in Peer reviewed magazines. 6 months ago we wrote article about our Process flow to create Cushions and about our understanding Fire and Brilliancy phenomena’s. but this article has 30.000+ words( even without detail explanation our metrics . for details explanations our metrics we need other 20.000+ words) and we do not know any magazine in diamond industry which has ability to publish it. Last months we are trying to split it into 2-3 independent articles.
P/s did you read our Letter exchanged between the GIA cut study team and the cut group in 2007?

https://www.pricescope.com/journal/letter_editor_australian_gemmologist
 
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