Important changes to HCA Cut Adviser

[Garry H (Cut Nut)]

More than a year ago we decided that HCA was too strict, and so we reduced the penalty severity to 2/3rds of the previous rating.

We feel that we went a little too far and after some more research we decided to adjust the penalty to a midway point.
As stated in the fine print with every report ¡§This system is being continually fine-tuned and results may change without notice.¡¨

There have also been other changes made too the light return scores:

1. The penalty for table sizes has been tightened to 55% to 56%. Above and below this range a gradual penalty is added. The range covers 75% to 40% tables.
2. Some shallower proportion combinations have been penalised more heavily. This is a result of debates with Sergey Sivovolenko and Yuri Shelementiev from OctoNus and Moscow State Uni, and also Brian Gavin from A Cut Above. These debates led to surveys which showed that preferences for say 40.0„a pavilions combined with 33„a crown angled diamonds are variable ¡V some people love the star that never goes away, and others hate the effect. Overall I decided it is better to guide people to ¡§usual and normally accepted cuts¡¨ (to quote Dave Atlas).

I would like to thank all the other people who have contributed, including antagonists (Hi Roc

http://www.consumersgemlab.com/the_holloway_cut_adviser.htm ) and objective observers like Jasper Paulsen http://www.folds.net/diamond_design/index.html#ed_note_02

We hope that these changes have not inconvenienced anyone overly.
You can read more about the theory and mechanisms behind HCA at www.diamond-cut.com.au - although some of the information there will not reflect this recent change.

 

[justme]

I predict a heavy run on HCA in the very near future!

 

[RockDoc]

Garry

If my antagonism makes the product better and reliable, then I accomplished some of what I think is to the advantage of consumers.

40-75% TABLES PENALTIES?

I think until an industry accepted standard is reached where everyone agrees, I am not sure that the analysis is really helpful.

Now if you can get the industry to go along with your "formula" instead of AGS or others, and its accepted - then we have a different story.

Rockdoc

 

[AmPm]

We all do our bit Roc, and we hope some people appreciate what we do

Re large table ranges - do a search and see how many very large table >65% diamonds there are. I think this is quite relevant.

But what about the shallow stone critcism you have made in the past?

BTW we have a few ideas to help consumers eliminate poor symmetry stones from searches to make the whole search process much quicker and easier

 

[Garry H (Cut Nut)]

Bump

 

[Garry H (Cut Nut)]

Sorry, just bringing this notice to the top aagain.

 

[dymonite]

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On 2/6/2003 6:37:54 PM Cut Nut wrote:

You can read more about the theory and mechanisms behind HCA at www.diamond-cut.com.au - although some of the information there will not reflect this recent change.


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Garry,

Wil we be seeing an update of the revised HCA methodology in the near future? I think it will be important for people to see how you have justified these changes.



D