What makes skinny or fat arrows?

[arjunajane]

Hi,
I would love if anyone has some info on this, or can link me to something to learn more?
I''m wondering what makes the arrows in ideal RB''s skinny or fat, and how these effect performance? ie. is one preferable over another for performance, or is it just up to taste?

If anybody has any RL photo comparisons of stones that have skinnier or fatter arrows, that''s be greatly appreciated too!
TIA,


aj.

 

[strmrdr]

90% lgf%
10% crown/pavilion angle.
Is what determines them.
In some crown/pavilion angle combos they are a preference issue.
In others its a performance issue.
Generally towards the middle range 40.6-40.9 pavilion with 34.5-34.9 crown its a preference issue with reasonable lgf% (75%-85%) maybe a little on either side too.
Get outside that range and it can be a performance issue.

Some cuts outside that range make the tradeoff for a specific look and performance in certain lighting: ie: oec which trading some brightness for fire and soft light performance.
Which makes sense when the dominate lighting at the time was soft lighting.

 

[strmrdr]

http://www.goodoldgold.com/Articles/MinorFacets/

 

[arjunajane]

ookaay..
thx strm for the link, I''m doing more reading now.
So say, someone like me who likes the appearance of the fatter arrows, but doesn''t want to compromise light return etc, what "ideal range" of angles would I want to look for?
Hope not asking too much!
cheers

 

[strmrdr]

Date: 4/27/2008 2:56:07 AM
Author: arjunajane
ookaay..
thx strm for the link, I''m doing more reading now.
So say, someone like me who likes the appearance of the fatter arrows, but doesn''t want to compromise light return etc, what ''ideal range'' of angles would I want to look for?
Hope not asking too much!
cheers

40.6-40.9 pavilion with 34.5-34.9 crown
Brian has some in the ACA line from time too time that are pretty nice.

 

[Lorelei]

Jane, here is a good link from WF which explains it well I think also.

http://www.whiteflash.com/diamonds_info/t/all_about.aspx?articleid=154&zoneid=22

 

[Ellen]

If you got to this page, about halfway down is a video with this intro, that might help give you and idea of what they look like.


A very interesting comparison of a 3ct GIA Ex with 40.8 pav/35.0 crown alongside a 2.68ct GIA Ex w/40.8 pavilion/34.5 and a 3ct Eighternity. The two 57 facet rounds differ most in their lower girdle facet length. One at 75% and the other at 82.6%. The difference in appearance is notable.

http://www.goodoldgold.com/video/

 

[arjunajane]

You guys are all the best!
strm, lorelei and ellen thankyou so much for all the info and the quick responses.
I haven''t had time to read everything yet but just wanted to say thanks

 

[Ellen]

Welcome!

 

[arjunajane]

ellen, out of interest what combo is yours?

 

[Ellen]

Going by the Helium report, it''s

CA 34.10

PA 40.95

LGF 76.9

 

[arjunajane]

So, if I'm getting it then your's would be considered to have fatter arrows?
Sorry, I know this is probably class 1.01, I just thought it was about time I started learning! I really like chunkier fire etc in diamonds, and am trying to figure if chunkier arrows = this effect, or what else comes into it. There's so much to learn about RB's!
Am I making any sense..?

ETA: Ellen I just watched that GOG vid, and as usual jon helps explain things I don't grasp with a great and pretty vid! Thankyou again for the link, I think I'm starting to get it....

 

[Ellen]

Date: 4/27/2008 9:07:54 AM
Author: arjunajane
So, if I''m getting it then your''s would be considered to have fatter arrows?
Sorry, I know this is probably class 1.01, I just thought it was about time I started learning! I really like chunkier fire etc in diamonds, and am trying to figure if chunkier arrows = this effect, or what else comes into it. There''s so much to learn about RB''s!
Am I making any sense..?

Technically no, but compared to many they are just slightly towards the shorter side. My stone definitely gives off big, bold flash though, with hints of smaller sparks. Me loves it.

If you do a search for "lgf", you''ll get a few really good threads that go in depth about them. Maybe more than you want to know!

 

[Rhino]

The diamond in that vid happened to be bems 2.68ct. When she flew in from Canada to see that one live it literally jumped at her.

While short lower girdles will generally contribute to a broader chunk of flash you don''t completely sacrifice it entirely by going to longer lower girdles because while arrows may get thinner you are at the same time broadening the lower halves causing them to have more real estate on the pavilion and they too are great sources for broad flash. The key difference is that in diffuse lighting you''ll get a slightly more splintery contrast pattern, no sacrfice in brightness whatsoever, while in spot lighting you''ll see more pin flash. Not long ago I had some purposely cut with lower halves over 80% because I share bems passion for them and those who enjoy the appearance.

After pavilion main angles, the lower halves have one of the greatest impacts on the diamonds appearance considering all the measurements taken.

All the best,

 

[lisa1.01fvs1]

Mine has chunky arrows and is C: 35.2, P: 40.9, LGF: 75%.

I guess the definition of chunky is in the eye of the beholder.

I can readily see the arrows in some lighting and I get the broad flashes which I prefer.

 

[diagem]

Date: 4/27/2008 10:37:08 AM
Author: Rhino
The diamond in that vid happened to be bems 2.68ct. When she flew in from Canada to see that one live it literally jumped at her.

While short lower girdles will generally contribute to a broader chunk of flash you don''t completely sacrifice it entirely by going to longer lower girdles because while arrows may get thinner you are at the same time broadening the lower halves causing them to have more real estate on the pavilion and they too are great sources for broad flash. The key difference is that in diffuse lighting you''ll get a slightly more splintery contrast pattern, no sacrfice in brightness whatsoever, while in spot lighting you''ll see more pin flash. Not long ago I had some purposely cut with lower halves over 80% because I share bems passion for them and those who enjoy the appearance.

After pavilion main angles, the lower halves have one of the greatest impacts on the diamonds appearance considering all the measurements taken.

All the best,

Real estate? New slang?

Sorry Rhino,

Of-course you are sacrificing chunk appearance when going longer with lgf''s..., thats why you get splintery & pin patterns...

 

[arjunajane]

Cheers Jon for the explanation! I''d probably never get Any of this stuff if it weren''t for your vids and tutorials

I have to admit that one of Bem''s really outshone the others'' clearly, its obvious why she chose it!
You mentioned you had some like that specifically cut in the past, out of interest are there any plans for more like that?

Thanks again Jon for the info, and also for my awesome PoH - I''m currently very much enjoying the bold And pin flash from it Very Very much

Thankyou Lisa for filling me in on your lovely stone too - i guess you''re right that its a matter of opinion though...
I thought if I start trying to learn what I like and why now, by the time I''m ready to upgrade my ering I Might just know what to get!

 

[beryl]

Date: 4/27/2008 2:43:43 AM
Author: strmrdr
90% lgf%
10% crown/pavilion angle.
Is what determines them.
In some crown/pavilion angle combos they are a preference issue.
In others its a performance issue.
Generally towards the middle range 40.6-40.9 pavilion with 34.5-34.9 crown its a preference issue with reasonable lgf% (75%-85%) maybe a little on either side too.
Get outside that range and it can be a performance issue.

Some cuts outside that range make the tradeoff for a specific look and performance in certain lighting: ie: oec which trading some brightness for fire and soft light performance.
Which makes sense when the dominate lighting at the time was soft lighting.

Strmdr:
Please clarify meaning of ''90% lgf%'', ''10% crown/pavilion angle''. I do not recognize these abbreviations/terminology.

 

[beryl]

AJ:
What means ''RL photo''?
I am preparing an article on arrows which could interest you.
Depth of pavilion halves is major factor in length of arrows.
You can create different arrows with simulation software.

Date: 4/27/2008 2:35:29 AM
Author:arjunajane
Hi,
I would love if anyone has some info on this, or can link me to something to learn more?
I''m wondering what makes the arrows in ideal RB''s skinny or fat, and how these effect performance? ie. is one preferable over another for performance, or is it just up to taste?

If anybody has any RL photo comparisons of stones that have skinnier or fatter arrows, that''s be greatly appreciated too!
TIA,


aj.

rows.

 

[Skippy123]

Great Info Storm, Lorelei, and Ellen!!

eta: I watched that video and it is on cushion's???? Is that right?? Anyone else see the same thing?

 

[lisa1.01fvs1]

Date: 4/28/2008 10:21:15 AM
Author: beryl
AJ:
What means ''RL photo''?
I am preparing an article on arrows which could interest you.
Depth of pavilion halves is major factor in length of arrows.
You can create different arrows with simulation software.

Date: 4/27/2008 2:35:29 AM
Author:arjunajane
Hi,
I would love if anyone has some info on this, or can link me to something to learn more?
I''m wondering what makes the arrows in ideal RB''s skinny or fat, and how these effect performance? ie. is one preferable over another for performance, or is it just up to taste?

If anybody has any RL photo comparisons of stones that have skinnier or fatter arrows, that''s be greatly appreciated too!
TIA,


aj.

rows.

Hi beryl, I get stummped all the time on the lingo.

RL = real life?

Lower Girdle Facet or were u questioning the #?

I think he means difference between C/P facets of 10%????

 

[Skippy123]

Date: 4/28/2008 10:40:11 AM
Author: Skippy123
Great Info Storm, Lorelei, and Ellen!!

eta: I watched that video and it is on cushion''s???? Is that right?? Anyone else see the same thing?

Never mind; got the right video now. Thankies