AGS introduces cut grading on DQR reports

[Serg]

Diagem,

Convex facets is one of reasons why 3D model could have bad edges junctions . Polyhedron model is noå good enough for convex facets

I will try find example and send.

Of course 3D scanner is not best way to measure flatness. It could be done much more cheaper , faster and with better accuracy

 

[diagem]

Date: 11/5/2008 9:41:36 AM
Author: Serg

Diagem,

Convex facets is one of reasons why 3D model could have bad edges junctions . Polyhedron model is noå good enough for convex facets

I will try find example and send.

Of course 3D scanner is not best way to measure flatness. It could be done much more cheaper , faster and with better accuracy

Serg..., do you think every facet on every Diamond can be polished to 100% flatness?

 

[Serg]

Date: 11/5/2008 10:08:59 AM
Author: DiaGem

Date: 11/5/2008 9:41:36 AM
Author: Serg


Diagem,

Convex facets is one of reasons why 3D model could have bad edges junctions . Polyhedron model is noå good enough for convex facets

I will try find example and send.

Of course 3D scanner is not best way to measure flatness. It could be done much more cheaper , faster and with better accuracy

Serg..., do you think every facet on every Diamond can be polished to 100% flatness?

Diagem,
I do not measure flatness in %.
flatness definitely could be better for fancy cuts and may be even for round cut than current best level. .
I depends from technology and time .
But may be current level H&A flatness is good enough

 

[diagem]

Date: 11/5/2008 10:25:06 AM
Author: Serg

Date: 11/5/2008 10:08:59 AM
Author: DiaGem

Date: 11/5/2008 9:41:36 AM
Author: Serg



Diagem,

Convex facets is one of reasons why 3D model could have bad edges junctions . Polyhedron model is noå good enough for convex facets

I will try find example and send.

Of course 3D scanner is not best way to measure flatness. It could be done much more cheaper , faster and with better accuracy

Serg..., do you think every facet on every Diamond can be polished to 100% flatness?

Diagem,
I do not measure flatness in %.
flatness definitely could be better for fancy cuts and may be even for round cut than current best level. .
I depends from technology and time .
But may be current level H&A flatness is good enough

Got you...

Now the next natural question would be (and I hope I am not stepping on anyone''s feet right now

),... Could VG symmetry be "good enough" for the current level of H&A???

 

[adamasgem]

Date: 11/5/2008 8:57:55 AM
Author: Serg
Marty,
Both

smoothness or Roughness

AND

Flatness( convex). Flatness is more critical for Brightness.

Labs grade only smoothness( Roughness )

Thanks for the clarification...

Unfortunately, you might only be able to see concavity with an optical flat on the table, but I don''t think we can measure what you are talking about on other facets currently because of small baselengths, maybe by laser methods? Haven''t thought about the requirements.

At first glance, I see roughness, like a bruted girdle (in the extreme) as critical for brightness, but I dont see , from an obvious viewpoint, the relative criticality for flatness in brightness, mathematically, that you speak of.

I liiken, and have modeled since the early ninetys, surface roughness as an variance (or quazi-randomness) in the angle of incidence when hitting an internal interface, when doing ray traces, e.g. when I hit the "plane" of a bruted girdle, the angle of incidence was modeled by likening it to not knowing where a ray hit on a half of a hemisphere, quazi-diffuse reflection. The coarser the surface roughness, the more one could "map" it

Seems to me that concavity would be classically more deterministic, and therefore, intuitively (and I might be wrong) having less of an effect on brightness, rather than more, as you suggest. It (minor concavity) would alter or shift the focus point; I''m thinking of lens equations analogies.

 

[adamasgem]

I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the "known" plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

 

[strmrdr]

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.

Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?

Visual optical symmetry without physical symmetry becomes difficult, at best.

Which is why I feel you can not separate finish from cut grade they are 2 parts of the same puzzle.

 

[diagem]

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

 

[Garry H (Cut Nut)]

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the 'known' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

The easiset way to check is by examining say a fluorescent tube at some distance by simply holding the diamond still and looking at the reflection of the tube (or the dimples in a fluoro light disperser that is often over the light source) on the facets surface.
You do this without a lens and simply focus on the distance to the light, not the distance to the stone.
No magnification should be used.
You can do this for every facet on a 1ct sized round stone.
I imagine a telescope would work for use at greater distance - possibly with a laser based light source like a graph paper.

PS sergey taught me this trick about 4 years ago during a very fine meal in a German restaurant

 

[Serg]

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

Marty,
small non flatness is not important for optical symmetry.

 

[strmrdr]

For those that were complaining about me me calling it proportion based....

"AGS Laboratories' new proportion-based Diamond Quality® Report"
http://www.agslab.com/product_diamond_quality_report.php

 

[diagem]

Date: 11/5/2008 2:37:14 PM
Author: Garry H (Cut Nut)

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

The easiset way to check is by examining say a fluorescent tube at some distance by simply holding the diamond still and looking at the reflection of the tube (or the dimples in a fluoro light disperser that is often over the light source) on the facets surface.
You do this without a lens and simply focus on the distance to the light, not the distance to the stone.
No magnification should be used.
You can do this for every facet on a 1ct sized round stone.
I imagine a telescope would work for use at greater distance - possibly with a laser based light source like a graph paper.

PS sergey taught me this trick about 4 years ago during a very fine meal in a German restaurant

I would imagine you need to be a bit more sophisticated to notice a minuscule or minimum concave/convex facet.
Just my guess...

 

[diagem]

Date: 11/5/2008 2:58:38 PM
Author: Serg

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

Marty,
small non flatness is not important for optical symmetry.

So why would less than EX polished surface of a facet be?

 

[adamasgem]

Date: 11/5/2008 2:37:14 PM
Author: Garry H (Cut Nut)

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

The easiset way to check is by examining say a fluorescent tube at some distance by simply holding the diamond still and looking at the reflection of the tube (or the dimples in a fluoro light disperser that is often over the light source) on the facets surface.
You do this without a lens and simply focus on the distance to the light, not the distance to the stone.
No magnification should be used.
You can do this for every facet on a 1ct sized round stone.
I imagine a telescope would work for use at greater distance - possibly with a laser based light source like a graph paper.

PS sergey taught me this trick about 4 years ago during a very fine meal in a German restaurant

Gary ..New concept on me...

Question..

1) Using monocular or stereo vision?
2) Any idea of "level" of "concavity" that can be discriminated, is it better or worse observability than using Newton rings on an optical flat?
3) Stone better be absolutely dry and free of grease as you would, I think, see meniscus effects predominate

3)

 

[adamasgem]

Date: 11/5/2008 3:34:31 PM
Author: DiaGem

Date: 11/5/2008 2:58:38 PM
Author: Serg

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

Marty,
small non flatness is not important for optical symmetry.

So why would less than EX polished surface of a facet be?

Irv.. I think we might be interchanging optical symmetry and brightness.. Serg was saying before, I believe, that convex/concave facets effect brightness, but I think that depends on the source model used.

Sergey Do we see concave or convex facets, in general?
I can see reasons for rolled edges and more convex facets
Interesting

 

[Serg]

Marty,
re:2) Any idea of "level" of "concavity" that can be discriminated, is it better or worse observability than using Newton rings on an optical fl
Newton ring method is not good for diamonds
1) You need relative big facet to us it( small facets is so difficult for such method. )
2) You need do it separately for each facet

Possible, but very costly( time costly firstly)

re:Sergey Do we see concave or convex facets, in general?

Convex , of course

Btw. What is resume of hot ASG Gold discussion?

Do you still think what my apples are mutants?

 

[Garry H (Cut Nut)]

Date: 11/5/2008 3:32:40 PM
Author: DiaGem

Date: 11/5/2008 2:37:14 PM
Author: Garry H (Cut Nut)

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

The easiset way to check is by examining say a fluorescent tube at some distance by simply holding the diamond still and looking at the reflection of the tube (or the dimples in a fluoro light disperser that is often over the light source) on the facets surface.
You do this without a lens and simply focus on the distance to the light, not the distance to the stone.
No magnification should be used.
You can do this for every facet on a 1ct sized round stone.
I imagine a telescope would work for use at greater distance - possibly with a laser based light source like a graph paper.

PS sergey taught me this trick about 4 years ago during a very fine meal in a German restaurant

I would imagine you need to be a bit more sophisticated to notice a minuscule or minimum concave/convex facet.
Just my guess...

Guys it takes you less time to test it than it does to write your replies - very very simple stuff.

Sergey a camer set up does it quite well - you should all remeber I posted tests once with ventian blinds

 

[diagem]

Date: 11/5/2008 4:12:32 PM
Author: Serg


re:Sergey Do we see concave or convex facets, in general?

Convex , of course

So..., that must somehow affect appearance..., no?

 

[Serg]

Date: 11/5/2008 5:05:18 PM
Author: DiaGem

Date: 11/5/2008 4:12:32 PM
Author: Serg



re:Sergey Do we see concave or convex facets, in general?

Convex , of course

So..., that must somehow affect appearance..., no?

Diagem,

I can not understand questions in last your posts

 

[adamasgem]

Date: 11/5/2008 4:12:32 PM
Author: Serg

Marty,
re:2) Any idea of ''level'' of ''concavity'' that can be discriminated, is it better or worse observability than using Newton rings on an optical fl

Newton ring method is not good for diamonds
1) You need relative big facet to us it( small facets is so difficult for such method. )
2) You need do it separately for each facet


Possible, but very costly( time costly firstly)


re:Sergey Do we see concave or convex facets, in general?

Convex , of course

Btw. What is resume of hot ASG Gold discussion?

Do you still think what my apples are mutants?

OK So it seems you are talking about is " rolled" facet edges verses what I would consider a convex facet like a cylindrical lens, if I get what you are talking about.

Going back
1) As I said, I think a mistake was made in "naming"
2) I don''t think you can say much more with the data presented other than one system is admittedly more liberal in some respects in rewarding the top grade, and the two might never overlap.

3) Many in on this discussion were in Vegas when the discussions about scintillation metrics was held (Garry , John, Beryl, Paul, and Wink were as I remember), so I envision a change in the PGS boundaries when that is mentioned.

Can''t agree with you...

 

[adamasgem]

Date: 11/4/2008 8:42:28 PM
Author: michaelgem

(Near the borders, scanning errors can give incorrect grades as well as rounding errors. MDC)

It is not ONLY "near the borders" that this can happen, it depends on the inherent asymmetric nature of the stone as well as position on the gradiant map. Looking at a quantized map, we don''t see even the variations within a box, let alone star and lgf variations

 

[diagem]

Date: 11/5/2008 5:09:11 PM
Author: Serg

Date: 11/5/2008 5:05:18 PM
Author: DiaGem

Date: 11/5/2008 4:12:32 PM
Author: Serg




re:Sergey Do we see concave or convex facets, in general?

Convex , of course

So..., that must somehow affect appearance..., no?

Diagem,

I can not understand questions in last your posts

Why Serg...

I am trying to follow you guy''s on the "perfect symmetry" type RB''s

You guys are discussing (for days) RB''s all the way down to the nano-differences of a 1/10th. (or even less) of a facet degree!
Rounding of GIA #''s is considered lesser than AGS''s non rounding system...
Polish surface must be almost absolute..., while it actually cant be absolute...
Using tools for light behaviour measurements..., while understanding that errors exist if measured on convex facets which usually appear on the Diamonds...

Etc..., etc...

There are soooo many factors (in a Diamond) that cant be judged or accurately measured by any scan/machine (as of yet, I believe)...

So are those "Super Ideals" grading reports actually official enough for what they are??? Or are they all based on some type of ranges that could actually mean not "Ideal" at all?

 

[beryl]

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the 'known' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

It is virtually impossible to produce a concave facet with a typical flat lap. Convexity probable exists on all facets made with 'flat' lap, even if it is perfectly flat. because of buildup of polish and swarf ahead of the stone and/or elasic deformation of the lap forming a 'wave' ahead of stone pressure area (no matter how rigid, all materials have some elasticity). Such flatness errors are generally too small to measure.
I worked for a company that made honing and lapping equipment; we dealt with quantities not normally realized by custoners. When they wanted 'flat', we asked 'how flat', When they wanted 'smooth' we asked 'how smooth' (all metals appear black at 1/10 microinch finish, require Newtoniam light rays to measure).
When cutting (colored stones) I judge flatness by tilting the stone to view reflection of a straight line, such as a fluorescent light, to see if it is straight, and tilt the stone to see that it stays straight as it moves across the surface; dropoff at leading edge of facet (when lapping) is common with colored stones for various reasons.
30 years ago there was a company that used cylindrical laps for automatic cutting of synthetic sapphires; this counter-acted the tendency to produce convex facets when cutting fast and thus produced an apparently flat facet !

 

[strmrdr]

Date: 11/5/2008 5:40:34 PM
Author: DiaGem

There are soooo many factors (in a Diamond) that cant be judged or accurately measured by any scan/machine (as of yet, I believe)...


So are those 'Super Ideals' grading reports actually official enough for what they are??? Or are they all based on some type of ranges that could actually mean not 'Ideal' at all?

For an RB the helium scanner measurements are for sure accurate enough to assign a grade, the top end sarin are acceptable.
It comes down to how accurate are the models produced.
The heart images are one of the best ways to tell.
With asschers and other fancies it is another story with the helium being acceptable and everything else questionable.
Some of the ones you cut no scanner is good enough for grading.

 

[strmrdr]

Date: 11/5/2008 5:21:50 PM
Author: adamasgem

Date: 11/4/2008 8:42:28 PM

Author: michaelgem

(Near the borders, scanning errors can give incorrect grades as well as rounding errors. MDC)

It is not ONLY 'near the borders' that this can happen, it depends on the inherent asymmetric nature of the stone as well as position on the gradiant map. Looking at a quantized map, we don't see even the variations within a box, let alone star and lgf variations

This is the biggest difference between gold and PGS is the range of lgf% and painting/digging allowed.
And how finely it is considered.
The shotgun approach of gold does not cut it compared to PGS.
In PGS the lgf% can move a stone at least one grade and maybe more within the range allowed by gold in some combos.
Painting and digging can move it much farther than 1 grade.
This is not taken into consideration on the charts.

 

[michaelgem]

Date: 11/5/2008 9:07:15 PM
Author: strmrdr

Date: 11/5/2008 5:21:50 PM
Author: adamasgem

Date: 11/4/2008 8:42:28 PM

Author: michaelgem (Near the borders, scanning errors can give incorrect grades as well as rounding errors. MDC)

It is not ONLY ''near the borders'' that this can happen, it depends on the inherent asymmetric nature of the stone as well as position on the gradiant map. Looking at a quantized map, we don''t see even the variations within a box, let alone star and lgf variations

This is the biggest difference between gold and PGS is the range of lgf% and painting/digging allowed.
And how finely it is considered.
The shotgun approach of gold does not cut it compared to PGS.
In PGS the lgf% can move a stone at least one grade and maybe more within the range allowed by gold in some combos.
Painting and digging can move it much farther than 1 grade.
This is not taken into consideration on the charts.

It is likely that such grade or more movements due to small quantizing or rounding errors in lgf% actually makes negligible visual differences in light performance, and should not have lowered the grade.

I remember criticism for stating my belief that the sweet spot for lgf% was 75-80 centered at 77. 77% is the target lgf% for many H&A cut diamonds, and most range from 75-80. But many here say it is a matter of taste, and thus should not affect the grade even beyond this range. Maybe AGS took a look at this and found no point in considering lgf% more finely than they have in the Gold System. They did research this system long and hard before revealing it.

Michael D. Cowing

 

[diagem]

Date: 11/5/2008 7:53:22 PM
Author: beryl

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

It is virtually impossible to produce a concave facet with a typical flat lap. Convexity probable exists on all facets made with ''flat'' lap, even if it is perfectly flat. because of buildup of polish and swarf ahead of the stone and/or elasic deformation of the lap forming a ''wave'' ahead of stone pressure area (no matter how rigid, all materials have some elasticity). Such flatness errors are generally too small to measure.
I worked for a company that made honing and lapping equipment; we dealt with quantities not normally realized by custoners. When they wanted ''flat'', we asked ''how flat'', When they wanted ''smooth'' we asked ''how smooth'' (all metals appear black at 1/10 microinch finish, require Newtoniam light rays to measure).
When cutting (colored stones) I judge flatness by tilting the stone to view reflection of a straight line, such as a fluorescent light, to see if it is straight, and tilt the stone to see that it stays straight as it moves across the surface; dropoff at leading edge of facet (when lapping) is common with colored stones for various reasons.
30 years ago there was a company that used cylindrical laps for automatic cutting of synthetic sapphires; this counter-acted the tendency to produce convex facets when cutting fast and thus produced an apparently flat facet !

Thanks..., thats what I was thinking...


The more i read..., the more I learn that when it comes to Diamond proportions..., measuring is never (and will probably be never) absolute.

 

[diagem]

Date: 11/5/2008 7:53:22 PM
Author: beryl

Date: 11/5/2008 2:25:06 PM
Author: DiaGem

Date: 11/5/2008 1:59:04 PM
Author: adamasgem
I might also add that both surface roughness and concavity issues make Ray tracing impossible to use for optimization purposes because the reflected ray is not in the ''known'' plane of incidence.
Any concavity on one or more facets, woud distort the visual optical symmetry, would it not?
Visual optical symmetry without physical symmetry becomes difficult, at best.

I believe it would!

How do we know the facets have no concavity??

After all..., once you transform/change the natural form/shape of a Diamond from its whole or complete rough structure..., its hardness becomes vulnerable and its shape may become distorted.

It is virtually impossible to produce a concave facet with a typical flat lap. Convexity probable exists on all facets made with ''flat'' lap, even if it is perfectly flat. because of buildup of polish and swarf ahead of the stone and/or elasic deformation of the lap forming a ''wave'' ahead of stone pressure area (no matter how rigid, all materials have some elasticity). Such flatness errors are generally too small to measure.
I worked for a company that made honing and lapping equipment; we dealt with quantities not normally realized by custoners. When they wanted ''flat'', we asked ''how flat'', When they wanted ''smooth'' we asked ''how smooth'' (all metals appear black at 1/10 microinch finish, require Newtoniam light rays to measure).
When cutting (colored stones) I judge flatness by tilting the stone to view reflection of a straight line, such as a fluorescent light, to see if it is straight, and tilt the stone to see that it stays straight as it moves across the surface; dropoff at leading edge of facet (when lapping) is common with colored stones for various reasons.
30 years ago there was a company that used cylindrical laps for automatic cutting of synthetic sapphires; this counter-acted the tendency to produce convex facets when cutting fast and thus produced an apparently flat facet !

True..., but I know it exist on a sawn plane of the Diamond when divided...
Question is..., when polished on a flat lap..., does the concavity disappear? Or flatness errors remain or can be recreated naturally?

 

[strmrdr]

Date: 11/5/2008 10:13:55 PM
Author: michaelgem
I remember criticism for stating my belief that the sweet spot for lgf% was 75-80 centered at 77. 77% is the target lgf% for many H&A cut diamonds, and most range from 75-80. But many here say it is a matter of taste, and thus should not affect the grade even beyond this range. Maybe AGS took a look at this and found no point in considering lgf% more finely than they have in the Gold System. They did research this system long and hard before revealing it.



Michael D. Cowing

around tolk sure 77(75-85) is good but when you get out into the fic range then 77 is to short.
When you get around 34/41 75 is a lgf% mismatch to the c/p angle combo and you get large dead zones in etas and detas.
Which confirms what I first saw with my own eyes almost 5 years ago.

 

[Garry H (Cut Nut)]

Re scanner accuracy - you aint seen nothing Gentlemen:
http://www.google.com/patents?id=-zmBAAAAEBAJ&dq=sivovolenko+diamond

Michael you can be myopic - a consumer knows more than you - read and learn.
You like to simplify complex issues - they dont always conform, Storm is right.