Idealscope rating

[ib40.5]

Gary and the gang, Has anyone given any thought to applying a scale to the Idealscope? i.e being able to say a particular diamond, by someone trained or "certified" (G.G., C.G., or proprietary Halloway training) rates a number or a percentage or whatever. Thanks.

 

[Garry H (Cut Nut)]

Great idea - but how would you rate each of these images?

I would give them all excellent (10 out of 10) but they are all very different

there are too many options and too many preferences.

 

[valeria101]

Err... reading color gamma and pattern consistency, perhaps?

Looking for these two criteria, the bottom left stone will end up a bit out of the others' league. And the bottom-left piece seems either colored itself or pictured with some different color background. The resulting ranking being: bottom right, top left, top right and bottom right.

From the wrong side of the screen, it appears that Isee2 does something simmilar (making up scores based or related to a controlled reflection).

 

[ib40.5]

O.K. If from the Idealscope images it can be determined that a certain diamond is a F.I.C. as opposed to a B.I.C, could we not then say a certain diamond is then a "B.I.C.:9"? Is this making a simple tool overly complicated? On another note, Is there any input on the idea of "rocking and tilting" the stone while viewing with the Idealscope, in effect changing the light source? Thanks, Ian

 

[valeria101]

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On 9/4/2004 8:04:53 AM ib40.5 wrote:

O.K.

Is this making a simple tool overly complicated?
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I would think so

although why not, if it is not overly complicated for you !?

 

[Garry H (Cut Nut)]

Someone is going to need to make value judgements.

It is not a good system.
Your assessment of the images is very good IB40, but they are more valuable to make those sorts of judgements than giving a digital score.
Besides what are you going to do with symmetry dviations ???

 

[valeria101]

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On 9/4/2004 9:02:24 AM Garry H (Cut Nut) wrote:

Someone is going to need to make value judgements. It is not a good system.
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Aren't there a few already made? This is an evaluation tool after all. But numbers would be more contestable than these pictures and the refference chart, so... even if it is feasible to turn a 'scope reading into some numbers (like the Bscope and Isee2 and the Gem Adviser do, for what that's worth) there does not seem to be a strong case pro, as you say.

 

[ib40.5]

I agree, that I'm making it overly complicated. Clarity grading,even color grading, can be subjective. Proportion analysis can be objective, though the combination of said proportions can produce subjective results. I feel that the IdealScope (and similar tools) fundamentally aid in forming a solid opinion of a stone. It just seems that G.G.'s or F.G.A.'s in training could benefit from using this tool. What a fabulous way to do pavilion depth, table %, and other estimations that I am too rusty to remember! Not to mention, symmetry quality using the IdealScope is apparent to the utmost novice. Many thanks, Ian.

 

[Garry H (Cut Nut)]

OK kiddies

Put some numbers on these

 

[ib40.5]

Argh. I may not sleep this weekend. Does the second diamond, bottom row, exhibit better light return compared to the first diamond, bottom row, even though the symmetry is not as precise? If this is the case, then I think I'm getting a better grip. Also, does the intensity of the red correspond to the "efficiency" of light return? Thanks so much, Ian

 

[Garry H (Cut Nut)]

The red intensity is not proportional - half the percieved intensity = 3/4 light return.
A tiny bit of pink like inside the table in stone 2 top row = maybe 20% light loss compared to the stone 1 which looses 15% in the same region.

You see why I have never tried to make a numeric scale - especially since all the various photographic systems people use (with or without photoshop or recylcled stock photo's) change the results for the same stone.