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Author Topic: Concave Faceting Competition  (Read 618 times)

Ghost

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Re: Concave Faceting Competition
« Reply #15 on: July 02, 2017, 04:19:53 PM »
Outside the restricted area of judged competitions, and in the real world of every day activity, concave facet faceting will compete with flat facet faceting as a means of enhancing gems in the same way that cars competed with the horse and buggy as a means of land transport.   The outcome of that competition is not yet clear as it is still very early days for concave faceting.
Regards,   Ghost.

FlashGP

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Re: Concave Faceting Competition
« Reply #16 on: July 02, 2017, 10:00:41 PM »
Perhaps I was a bit hasty in deciding the rule change ruled out Section 8A.  I had thought a continuous girdle was a facet, after all as a curved surface is judged as a facet and the definition of facet previously allowed curved surfaces.

Closer inspection of the rules shows the only link to be the judging of a curved surface as a facet.  Query if this can happen or if it is relevant. 

The definition of meet accommodates the change, as it talks about the junction of 4 facets or 3 facets and a curved surface.

Ghost, you make a good point about the concave faceting.  I think that it can be easily overdone, but it certainly adds bling to a stone.

Paul Sabota made a good point on the  AFG Forum, it takes a lot of effort to introduce a new section so when doing so, it would be good to expand the rules to accommodate as many different techniques as possible.

The current manual (edition 8) is dated April 2015, but It wasn't until 2017 that it was widely used.  Any rule changes may take a few years to get agreed and in use.

This goes to my initial point, I don't understand why the rules couldn't have remained as they were until a comprehensive review of the rules was made.  Even though concave faceting gives a flashier stone, the criteria for judging in groups 8 to 11 really have few marks based on Visual Effect, the only judging point that is perhaps subjective.  After that a concave faceted stone that has the same facet shapes as the design competes on an equal footing with flat facets, and they are harder to do.

This means that many of the rules for faceting competitions should translate equally well for concave facets. 

WHAT WOULD I CHANGE.
I would restrict the declaration ruling out concave facets to Groups 8 and 9.

Groups 10 and 11 allow curved surfaces provided that they constitute no more than 50% of the stone.  Hence concave facets can be included in a design set for a competition in these sections.  Freeform faceting also fits into either Group 10 or Group 11 depending on whether a table or apex crown is used.

However if the definition of Facet excludes curved surfaces, then the curved surfaces are not judged in the 3 the judging criteria relating to Facets. I would argue that we restore the definition of Facet so that curved surfaces can continue to be  judged in the three Facet criteria in the judging sheet.

I would also include a section catering for other forms of OMF "facets" such as V shaped grooves and hemispherical additions.  I would also introduce a section for laminated faceted stones, much the same as we have for doublet and triplet opals.

Keep the ideas and debate coming.

regards Flash

Yours Sincerely
Flash (Gordon)

journeyman

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Re: Concave Faceting Competition
« Reply #17 on: July 02, 2017, 10:18:46 PM »
Hi  Ghost, that's pretty good, I like it and the more I look at it the more I am turning my thoughts in that direction also. Maybe not so "anything goes"  but pretty close. Have to think of the poor Judge.  Have already started writing, thinking of a new Group, 4 sections for the 4 styles 1 Judging sheet with variable features with emphasis on Aesthetic Appeal. It will take awhile to get it together.
 Gordon, you are correct, Section 8&9 have been restricted to only allow flat facets. 8A is another story. The rules already allow curved facets in Section 10 & 11 and my first posts indicated section 11 could be expanded by just adding another section sequence number. Nothing else needs changing. However some other ideas were thrown into the debate so now i'm turning perhaps to start a whole new section as above and my previous curve ball post.


Interesting times ahead
Paul

FlashGP

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Re: Concave Faceting Competition
« Reply #18 on: July 02, 2017, 10:59:54 PM »
Thanks Journeyman, since writing the last post, I prepared a post for the AFG Forum and refined it a little.

The only argument against concave facets in Standard Cuts as I see it is the inherent advantage OMF facets give under the Visual Appeal judging feature (a total of 6 marks is allocated for this feature).  This is because the head shaddow effect in standard brilliants and standard step cuts when the refractive index is low means concave facets should return more light.  If Quartz is the chosen stone, a standard cut would give a Visual Effect Score of probably 4 or 5 tops if the judge follows the criteria, but an OMF cut should return a 6. 

But yes, a judge may find it more challenging to judge OMF cuts until they are experienced at them.

My latest thinking on the modifications is as follows.

WHAT WOULD I CHANGE?
I would remove "Concave facets are not permitted on "Standard Cuts".  The first sentence of that paragraph has the effect of concave facets being used in Groups 8 or 9 unless the relevant schedule allows their use.  That is, don't restrict the competition committee in their choices here.

I don't see a reason why a competition schedule couldn't have an OMF section using a standard design.  Personally I think it would be rare, but it would showcase the difference between OMF and traditional cuts.

Groups 10 and 11 allow curved surfaces provided that they constitute no more than 50% of the stone.  Hence concave facets can be included in a design set for a competition in these sections.  Freeform faceting also fits into either Group 10 or Group 11 depending on whether a table or apex crown is used.

However not all OMF designs use curved surfaces, some use V shaped grooves and hemispherical cuts.  I would extend the definitions of Groups 10 and 11 to allow OMF designs.  I would also introduce a definition of Optically Modified Facet and extend Curved Surface to include Optically Modified Facets.  This would expand sections 10 and 11 to include all OMF cuts as well as extend the definition of Facet so that OM Facets can be judged as facets (e.g. facet surfaces true, etc).

The new rider about facets being flat unless otherwise specified at the start of the rules will require the competition committee to specify when OMF facets can be used.

The competition committee may then set competitions for OMF as they see fit.

I would also introduce a section for laminated faceted stones, much the same as we have for doublet and triplet opals.

Happy faceting.
Yours Sincerely
Flash (Gordon)

FlashGP

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Re: Concave Faceting Competition
« Reply #19 on: July 02, 2017, 11:07:38 PM »
Going back to the original AFG Forum question, Should we have a concave facet competition.

I say Yes, but I don't have an OMF machine and as we don't know the level of interest, I would like to see a Group 10 or Group 11 competition which sets a stone design capable of getting full Visual Effect marks with flat facets and then allowing concave facets to compete in the same comp.

I would also allow all forms of OMF that fit the design.  The individual facetor can then chose the type of OMF cut to best suit the design.  This should help encourage innovation in this area.

Given that the only variance is the Visual Effect mark, the design should level the playing field marks wise.  OMF designs may have more of a WOW factor, but I would be interested in seeing them side by side with a flat facet cut to actually see how much they improve the cut.

regards Gordon.
« Last Edit: July 02, 2017, 11:13:55 PM by FlashGP »
Yours Sincerely
Flash (Gordon)

swirly

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Re: Concave Faceting Competition
« Reply #20 on: July 02, 2017, 11:45:04 PM »
all you are going to do is make the rules so complex,as to take the fun out of faceting comps,and put people off entering.

FlashGP

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Re: Concave Faceting Competition
« Reply #21 on: July 03, 2017, 07:40:54 AM »
I'm not so sure about whether it will make the rules much more complex at a competitor level.  Nothing should change other than the choice of which section to enter.  After all a facet is either flat ou it is not.

It will make the rules more complex for the people setting the competition as they will have a larger range of choices when setting the condjtions of entry.  On that note some competition stewards in clubs don't know the rules.  Last year we had to appeal a judges assertion a cabbed fossil was not a cabochon but a fossil.  The stewards had no idea until I walked them through the rules.  A fossil can not be worked or polished, ergo once cabbed it ceases to be a fossil and becomes a cab just the same as for petrified wood which in its natural state is a fossil but is unquestionably a cab once cabbed.

I like objective measures as you learn from the results.  Subjective measures are frustrating because no two judges think alike. For example I get frustrated with silver comps because so many marks are subjective and modern designs don't  score as well as jewellery that looks like it was made 50 years ago.  It is frustrating to get full marks for the objective measures but half marks for the subjective measures.

But if we have an OMF design comp we will need to set some subjective criteria in an Asthetic Appeal section.  The trick will be to get rules that don't lock competitors into an era but allow for the contemporary.
Yours Sincerely
Flash (Gordon)

swirly

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Re: Concave Faceting Competition
« Reply #22 on: July 03, 2017, 09:01:00 AM »
well what more can i say!

FlashGP

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Re: Concave Faceting Competition
« Reply #23 on: July 03, 2017, 06:10:51 PM »
Swirly,

Your comments equally aapply to me. 

But I add that all input is valuable and your comments a timely reminder of the KISS principal, especially for competitors as many people learn by word of mouth as the rule book is already hard to read.

It is as if we need a forum for discussing how the rules work, or answering questions on the rules.

Having taken a deep breath and challenged my own assumptions last night, and re-read the rule book, i think the modification to the rules I suggested would open up the scope for committees to add competitions for OMF without the need for many of the additional sections I was initially discussing.

Unfortunately the devil is in the detail in the definitions.  An explanation of how to interpret them and a statement of intent stating the rule changes were designed to give competition committees the freedom to create competitions intended to encourage competitors to develop themselves and faceting wouldn't go astray.

Happy faceting and don't let the rules put you off entering competitions.

Kimd regards
Flash
Yours Sincerely
Flash (Gordon)

journeyman

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Re: Concave Faceting Competition
« Reply #24 on: July 09, 2017, 08:38:03 PM »
Hi Ghost,
Good points there, yes, we have to start off slowly then build on it over several years, but we need some sort of base to start from. This is why i'm discussing it to gain ideas from cutters out there in faceting land. There have been over 400 reads to these posts but only a handful have written something about their ideas, so come on guys, if you want changes you need to speak up.
What do you think of the comments in post #9? about also including Freeform, Fantasy & Novelty? Surely some of you must have thoughts on these? Yes, Fantasy & concave need a special faceting machine, not everyone has a dedicated concave or fantasy machine, but the others don't - freeform & novelty, they can be cut on a normal faceting machine.
Paul beers

FlashGP

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Re: Concave Faceting Competition
« Reply #25 on: July 09, 2017, 09:48:24 PM »
I am all for making the scope of the rules as broad as possible.  Even though I don't have a concave facetor, having rules that allow for all types of OMF and other imaginable cuts, allows us to grow these fields using baby steps.

Who knows, maybe one day any one of us may have access to OMF or want to experiment with cuts not allowed by the current rules.

So speak up everyone and don't be afraid to say your piece. 
« Last Edit: July 09, 2017, 09:50:29 PM by FlashGP »
Yours Sincerely
Flash (Gordon)

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