Question for our cutters.

[Gypsy]

I like ovals and I read somewhere recently that to minimize bowtie they usually need to be pretty deep. Is this true, and can you explain it to me (dumb it down)?

When I'm searching for ovals for diamond seekers on here I usually put shallower depths in the search parameters so that I can eek out some spread. But I wonder if I'm making it harder on myself to find a nice oval for them.

Also, if it is true that a deeper cut can often help with the bowtie issue, does that apply to pears as well?

What are 'good' depth ranges to minimize bow tie?

Thank you!

Layla

 

[JulieN]

Quick answer:

you know how in deeper rounds the arrows turn white instead of black?

shallow tends to show more darkness.

 

[Gypsy]

Date: 3/1/2009 5:16:13 PM
Author: JulieN
Quick answer:

you know how in deeper rounds the arrows turn white instead of black?

shallow tends to show more darkness.

Um... no. I don't know this. Can you explain to me?? I'm only just starting to get into brilliant cuts.


The shallow tends to show more darkness makes sense. Once I think about it.

 

[strmrdr]

It is in the pavilion and lower girdle facet angles.
To shallow a pavilion you get obstruction, to deep a pavilion and the lower girdles start to leak.

The second variable is the pavilion main width which determines the size of the bow tie. (lgf% if you will)

 

[strmrdr]

The number is the pavilion angle...

 

[strmrdr]

second set

 

[strmrdr]

third set.

The exact angles and the degree of obstruction is also impacted by the crown height in relation to the pavilion angle and the l/w ratio of the stone as well as the optical symmetry.

There are also different faceting patterns that will produce different results.

 

[strmrdr]

lgf% changes

 

[diagem]

Karl..., you will have better visuals if you use the 4 fold pav. model...

 

[strmrdr]

Date: 3/1/2009 5:53:54 PM
Author: DiaGem
Karl..., you will have better visuals if you use the 4 fold pav. model...

true but I would have to do them in cut designer which would take to much time.
The DC default is 8

 

[diagem]

Date: 3/1/2009 5:58:15 PM
Author: strmrdr

Date: 3/1/2009 5:53:54 PM
Author: DiaGem
Karl..., you will have better visuals if you use the 4 fold pav. model...

true but I would have to do them in cut designer which would take to much time.
The DC default is 8

And all 8 are probably set at same ''default'' angles..., right?

 

[strmrdr]

Date: 3/1/2009 6:30:10 PM
Author: DiaGem
And all 8 are probably set at same ''default'' angles..., right?

Has the same adjustments as the DC RB.