Rhino''s Review: The Assessment of Fire Video

[dhog]

are you sure that fancy light box
wouldn''t work for a incubator for
chicken eggs.

 

[pricescope]

>Now there's a look in your eyes, like black holes in the sky.[/i]

Do diamonds look like black holes in the sunlight as shown in the Rhino's video (snapshot below)? In reality, when I look at a diamond in the sun, it looks to me much brighter (blinding actually).

I guess, the camera was adjusted automatically to the bright background and we only see direct reflections from a few facets, not what our eyes would see.

Rhino put a lot of time and work into the video, which is commendable. However, as Garry noticed, it only as good as to show that ideal cut stone look better than a really steep/deep one. In order to prove that there is probably no need in such lengthy video especially when the camera doesn't see it the same way as our eyes do.

I can be mistaken, of course.

 

[strmrdr]

Date: 8/9/2006 6:59:11 AM
Author: Pricescope

Now there''s a look in your eyes, like black holes in the sky.​

Do diamonds look like black holes in the sunlight as shown in the Rhino''s video (snapshot below)? In reality, when I look at a diamond in the sun, it looks to me much brighter (blinding actually).

I guess, the camera was adjusted automatically to the bright background and we only see direct reflections from a few facets, not what our eyes would see.

Rhino put a lot of time and work into the video, which is commendable. However, as Garry noticed, it only as good as to show that ideal cut stone look better than a really steep/deep one. In order to prove that there is probably no need in such lengthy video especially when the camera doesn''t see it the same way as our eyes do.

I can be mistaken, of course.

Its easy to knock someone elses work, here is a challenge for both ya and Gary .. you both have vid cameras and sunlight lets see some vids :}

 

[Garry H (Cut Nut)]

Date: 8/9/2006 8:12:26 AM
Author: strmrdr
Its easy to knock someone elses work, here is a challenge for both ya and Gary .. you both have vid cameras and sunlight lets see some vids :}

I am not knocking Rhino''s videos Storm. The video''s are great video''s.

If we made video''s what would we want to show?

I am knocking Rhino''s idea that Diamond Dock can be used with the wrong viewing angle and that having a light very close to a diamond, and resting the diamond on a light background close to a light - those things are wrong. Leonid has already made a video to show most of that. And Rhinos cinematography wins hands down.

But what can you learn from it all other than nice ice looks better than dead dog?
Rhino decided to make the connection between DIamond Dock and other environ''s. He is wrong about that. What video do you need Leonid or me to make to know that he is wrong about that?

Besdies it is gloomy winter here

 

[pricescope]

Date: 8/9/2006 8:12:26 AM
Author: strmrdr
Its easy to knock someone elses work, here is a challenge for both ya and Gary .. you both have vid cameras and sunlight lets see some vids :}

I never knocked down anybody''s work, Storm.

Rhino sent me the link for review and I spent time watching it and pointing on an editing mistake. Then he asked me to post it on Pricescope because he wanted peoples opinions and I said go ahead. He''s got many good feedbacks. Real scientists, however, are usually looking for criticism to help to improve the work and avoid mistakes.

I think Rhino is doing a great job trying to use new tools to show different aspects of the diamonds. We have Firescope/Idealscope, Brillincescope/Isee2, DiamCalc, Diamond Dock and now we have videos.

However, if the idea is not just to razzle-dazzle the crowd but to educate, one should explain both benefits and limitations of these tools because it is easy to get carried away and use them as sales-tools while the reality is much more complex.

I see Rhino invested a lot of work and thoughts in this video and I applaud his determination. If the whole idea of the video was just to show that ideal cut stone look better than very steep/deep one, that''s fine of course and it''s up to the author how much time this demonstration should take.

My concern is, however, how accurate camera represents the effects comparing to the human vision and whether such videos can be used to asses or illustrate diamond performance. Same question should be addressed to other diamond evaluation tools as well.

Strmrdr wrote: "you both have vid cameras and sunlight lets see some vids". What purpose would it serve? There should be an idea one wants to demonstrate in the videos, or pictures, etc

I can try to play with different cameras today in the sun light just to see whether cameras can show something close to what our eyes do but what would be the purpose of it?

As you know, Sergey et al are working on designing a scientific experiment of human reviewing different diamonds in the real live lighting environment. It''s not easy and will take time to do it right.

 

[aljdewey]

Date: 8/8/2006 4:59:04 PM
Author: Rhino

Ie. If you take a leaky diamond and place it against a black background the stone appears dark ... you can see through those leaky facets to the background behind it. If you take a leaky diamond and allow backlighting (like in tweezers or a transparent/translucent tray) the stone appears lighter.

If so, then why does the video Leonid posted show the exact opposite?

When the white paper moves into place as the background, the diamond takes on a dark look in the middle. When it''s moved away leaving a dark background, the diamond does appear whiter/lighter/brighter......as Garry suggested.

What accounts for this?

 

[pricescope]

Aljdewey, these are two different phenomena. Leakage shows up the best (worst) when there is no light from the background.

What Garry (and Sergey picture) is pointing out is that camera (and our eyes till some extend) adopts to the entire light coming into the lenses and diamonds look darker in the video/picture on a bright background.

 

[Rhino]

Date: 8/8/2006 7:40:38 PM
Author: Garry H (Cut Nut)

Date: 8/8/2006 4:59:04 PM
Author: Rhino
Hi Garry,

Mine will be in bold mate and between the lines.

Apologies to all those for the complex chart. But i hope this time Rhino that you will try to understand it and why you see what you see when you misuse DD

Misuse DiamondDock? I am not misusing it Garry. Not one iota. Once or if you actually acquire one and use it as I do on a daily basis, only then will you comprehend why I use it and feel the way I do. It does not show misleading views as you have suggested in the past. I do not wish to discuss this here in this thread but if you would like we can start a thread or talk about it in email.

Regards,

Rhino you have been invited many times in many seperate threads to discuss these issues over here: https://www.pricescope.com/community/threads/gia-diamond-dock-simple-summary.42538/

For what ever reason you choose not to.

Probabaly because when I''m talking to you I feel like I''m talking to a brick wall with answers from you that are generally disresptful and condescending. In every thread I''ve posted a video program in or participate on a subject that is controversial you speak like your crap doesn''t stink and that you "know it all". One reason why I generally don''t continue in those discussions and leave alot unanswered. Try talking to me like a human being and perhaps we can have an intelligent discussion.

Date: 8/8/2006 7:40:38 PM
Author: Garry H (Cut Nut)

Your answers posted above today to my questions further show your apparent lack of understanding and are not worth the waste of time to correct since the issue for you is rather like a religious belief debate.

But then we waited and you learned the weaknesses of many of you prior beliefs about your latest toys. I can wait a bit longer.

Any limitations I learned regarding technologies we employ I learned from hands on experience and comparison to real world observation testing. Something I would URGE any person who consults any technology including your own inventions as well as my own. Try not to be so condescending in your tone and perhaps I''ll stick around to finish a conversation. I see Leo has contributed and Alj has a question which I''d also like to comment on.


Regards,

 

[Rhino]

Date: 8/8/2006 5:15:30 PM
Author: Rod

Date: 8/8/2006 4:07:19 PM
Author: Rhino
Oops... almost forgot ya''ll on page 2.

How are ya rod,

Thanks for the kind words.

''1. The two stones being shown were of identical size (obviously your ideal stone was larger)
2. How the ideal stone would have compared against a stone in which the cut differences were not as significant (say an Excellent vs a Very Good cut)''

Check out my response to Ira (should be right above this). In the next vid we''ll be looking at these types of comparisons and specifically GIA Ex vs GIA VG but will not only be showing the differences in appearance but teaching on what causes the stones to get the VG instead of the Ex grade (ie. steep/deeps contributing too leakage, shallow/shallow''s etc.).

Good, thanks Rhino.......and I''m doing really well, btw. Be careful on this one. You don''t want to hurt us poor folks who believe our GIA VG stones rock!!

LOL... I think you''ll find its in good taste Rod. I don''t bash GIA VG''s. I simply point out and demonstrate what causes them to not get the Ex grade for cut to help folks better understand the "why''s" behind the GIA Cut Grading system. On a personal level, there are certain VG''s I prefer over others and in the history I''ve been here on these forums rod, I never knock or criticize a person for choosing whatever their own personal preference may be whether its an Ex, VG, G, f or poor.

All the best,

 

[Rhino]

Date: 8/8/2006 8:04:06 PM
Author: Garry H (Cut Nut)

Date: 8/8/2006 7:47:16 PM
Author: strmrdr
Garry you crack me up.....
talk about a one track mind..........
If Jon is too far one way on the DD then you are too far the other and the truth is some where in the middle.

It would be funny Storm, if the consequences were not so dire.
1. GIA give excellent grades to good and very good diamonds.
2. GIA give lessor grades to excellent diamonds
3. Rhino continues to misuse Diamond Dock by filming at high angles with the mistaken belief that tilting of the stones solves the problem. He does not need a protractor, just a seat.

Don''t you think I tried this? I did and I also responded to you about it in a past thread. In fact I recall taking photographs as well (if memory is serving me well). Don''t think I''m not listening and also testing your theories Garry.

To settle forever the issue of whether I am using the DD correctly or not why don''t you just contact any of the research gemologists at GIA and ask them? Point them to any of the material I''ve published (video or photography) and simply ask Garry. That is, if you are sincerely interested in the truth and my integrity in reporting what I am seeing as accurately as I know how.

Regards,

 

[Rod]

Date: 8/9/2006 1:59:51 PM
Author: Rhino

Date: 8/8/2006 5:15:30 PM
Author: Rod

Date: 8/8/2006 4:07:19 PM
Author: Rhino
Oops... almost forgot ya''ll on page 2.

How are ya rod,

Thanks for the kind words.

''1. The two stones being shown were of identical size (obviously your ideal stone was larger)
2. How the ideal stone would have compared against a stone in which the cut differences were not as significant (say an Excellent vs a Very Good cut)''

Check out my response to Ira (should be right above this). In the next vid we''ll be looking at these types of comparisons and specifically GIA Ex vs GIA VG but will not only be showing the differences in appearance but teaching on what causes the stones to get the VG instead of the Ex grade (ie. steep/deeps contributing too leakage, shallow/shallow''s etc.).

Good, thanks Rhino.......and I''m doing really well, btw. Be careful on this one. You don''t want to hurt us poor folks who believe our GIA VG stones rock!!

LOL... I think you''ll find its in good taste Rod. I don''t bash GIA VG''s. I simply point out and demonstrate what causes them to not get the Ex grade for cut to help folks better understand the ''why''s'' behind the GIA Cut Grading system. On a personal level, there are certain VG''s I prefer over others and in the history I''ve been here on these forums rod, I never knock or criticize a person for choosing whatever their own personal preference may be whether its an Ex, VG, G, f or poor.

All the best,

I have every confidence you will treat the subject with respect!!! My comment was somewhat tongue in cheek. I love my VG rock. It doesn''t really matter to me whether anyone else thinks it''s kicken. Well, maybe just a little, but in the end, it''s my eyes that have to be pleased. And, my pocket book too!

Thanks Rhino!!

 

[Rhino]

Date: 8/9/2006 10:01:41 AM
Author: aljdewey

Date: 8/8/2006 4:59:04 PM
Author: Rhino

Ie. If you take a leaky diamond and place it against a black background the stone appears dark ... you can see through those leaky facets to the background behind it. If you take a leaky diamond and allow backlighting (like in tweezers or a transparent/translucent tray) the stone appears lighter.

If so, then why does the video Leonid posted show the exact opposite?

When the white paper moves into place as the background, the diamond takes on a dark look in the middle. When it''s moved away leaving a dark background, the diamond does appear whiter/lighter/brighter......as Garry suggested.

What accounts for this?

Hi Alj,

This thread is funny because different types of lighting are being discussed as well as different types of backdrops. I totally understand Leo''s graphic/video and Sergey''s as well. There are certain commonalities in what I''m showing as well. Let me illustrate and hope this helps clear things up in your mind.

Firstly ... my video was specifically showing fire as observed in spot lighting environments.

In environments where strong spot lighting exists ideal cut diamonds takes on a darker body appearance, however the flashes of light will generally always be stronger and happening at a greater frequency. You can clearly see this phenomena in each of the video scenes I''ve recorded. I''m attaching a photograph I just took in our store that is taken in spot lighting. In this photgraph you can plainly see the darker body appearance of the H&A stone. The leaky stone takes on a lighter apperance.

The reason for this doesn''t require a PHD in rocket science. It''s rather simple to understand when you understand how diamonds react/handle light.

The reason the ideal cut takes on a darker body appearance is because it is blocking back light and generally only reflecting what is in front of the stone. This same phenomena (similar) is seen in IS images becuase in an IS image, none of the backlight is seen through the crown of the diamond. The red/blacks you see in IS images are strictly reflections from above. Not below. Only in leaky diamonds will you see what is behind the diamond. In the case of IS images it will be the white backlighting ... in spot lighting environments it will be light from behind the diamond.

I''ll continue to answer in my next post with another graphic.

In this image you can plainly see the darker body appearance of the H&A and the lighter appearance of the non ideal. This is what is observed in normal viewing conditions and is generally confused with both the issues of *brightness* and/or *color*.

You with me so far?

Regards,

 

[Rhino]

oops... forgot the graphic.

H&A on the left ... non ideal on the right.

 

[Rhino]

Date: 8/9/2006 10:01:41 AM
Author: aljdewey

Date: 8/8/2006 4:59:04 PM
Author: Rhino

Ie. If you take a leaky diamond and place it against a black background the stone appears dark ... you can see through those leaky facets to the background behind it. If you take a leaky diamond and allow backlighting (like in tweezers or a transparent/translucent tray) the stone appears lighter.

If so, then why does the video Leonid posted show the exact opposite?

When the white paper moves into place as the background, the diamond takes on a dark look in the middle. When it''s moved away leaving a dark background, the diamond does appear whiter/lighter/brighter......as Garry suggested.

What accounts for this?

To answer your question more specifically ...

Whille I do not know the specs on Leo''s diamond (a leaker or an ideal cut) it appears he is introducing different lighting and backdrop to the situation which could easily confuse (hence Garry''s frustration with my commentary?). I''m going to assume it is a stone with a decent IS image, hence most facets functioning as reflectors. If this is indeed the case here is the reason for the phenomena. Leo ... if you could share the stats on this stone it would help.

I''m assuming Leonid is using non-diffused desklamp fluorescent lighting (correct me if I''m wrong Leo). This type of lighting is pretty strong ... enough to cause the darker body appearance I was talking about in my last post. Now ... when Leo holds that piece of white paper behind the stone he is adding strong contrast in relation to the diamond in front of it. The camera equipment he is using is "auto-contrasting" and adjusting for the bright white background behind it and causing the stone to appear dark or even underexposed. When he pulls that bright white background away the camera adjusts and the stone takes on the brighter appearance.

Strmrdr touched briefly upon the situation but this has to do with the quality of the equipment being used to do the videography or photography and the person operating the equipment as well. If the settings are not studied and adjusted to compensate for overexposure or underexposure it will result in images that do not represent what is actually being seen. I try to get, as much as I can, an accurate representation to what we''re seeing but then there are also the limitations of monoculare vision as compared to stereo vision that must be taken into account as well. All photography/videography is monocular while we all see in stereo, however we feel that this is the best means of communicating appearance short of seeing a stone in person.

Hope this helps.

Jon

 

[Rhino]

Date: 8/9/2006 6:59:11 AM
Author: Pricescope

Now there''s a look in your eyes, like black holes in the sky.​

Do diamonds look like black holes in the sunlight as shown in the Rhino''s video (snapshot below)? In reality, when I look at a diamond in the sun, it looks to me much brighter (blinding actually).

I guess, the camera was adjusted automatically to the bright background and we only see direct reflections from a few facets, not what our eyes would see.

Rhino put a lot of time and work into the video, which is commendable. However, as Garry noticed, it only as good as to show that ideal cut stone look better than a really steep/deep one. In order to prove that there is probably no need in such lengthy video especially when the camera doesn''t see it the same way as our eyes do.

I can be mistaken, of course.

So you''re a Pink Floyd fan eh?

We saw Gilmore this past April at Radio City and my daughter and I are going to see Roger Waters this September. We''re big Floyd fans here too.

Haha... Leo ... in answer to your question ... YES. If you take ideal cuts into direct sunlight the stone will take on that darker body appearance. The trade off of course (also demonstrated in the vids and a very positive one at that) are flashes of light that are way more intense and happening at a greater frequency than non-ideals. "Blinding" you might say.

The vid in direct sunlight is IMO the best example of this phenonma I''m talking about. Just look at the intensity of the rainbows popping out of that stone.

If you have any other questions, they are appreciated and I''ll do my best to answer.

Kind regards,

 

[Rhino]

Date: 8/9/2006 10:32:56 AM
Author: Pricescope
Aljdewey, these are two different phenomena. Leakage shows up the best (worst) when there is no light from the background.

What Garry (and Sergey picture) is pointing out is that camera (and our eyes till some extend) adopts to the entire light coming into the lenses and diamonds look darker in the video/picture on a bright background.

In an effort to further help your understanding Alj, here is a photograph I''ve taken of the same 2 stones I used above. BTW the leaker in these photographs is the identical stone I used in the video. The other stone in these photographs are of a 1.02ct I VS1 H&A stone. This photograph below demontrates Leo''s point above, however both the lighting environment and backdrop are changed now.

This lighting is diffused daylight fluorescent (taken under the GIA DD) and accurately depicts brightness. If this lighting were too strong and different temperature, then the H&A stone would take on the darker body appearance we were talking about previously. In this lighting we make the same assessments we''d see in natural diffuse daylight (outside on a cloudy day, in shaded sunlight, etc... see our vid on brightness for more comparisons) but this photograph IMO demonstrates what Leo is talking about above.... ie. Leakage shows up best when there is no light from the background. I took this photograph against a black background but I definitely prefer the neutral gray GIA provides with the DD as it does not cause any overexposure both in viewing and also in photography. I adjusted the brightness and contrast slightly on this image to better reflect what I am seeing but in these images (zoomed back and a macro shot) show plainly the effects of leakage when observed against a dark backdrop. It is easy to see that the H&A is the brighter diamond and highlights the view one would/should see in a diamond in these environments.

Kind regards,

 

[Garry H (Cut Nut)]

Date: 8/9/2006 2:14:33 PM
Author: Rhino

To settle forever the issue of whether I am using the DD correctly or not why don''t you just contact any of the research gemologists at GIA and ask them? Point them to any of the material I''ve published (video or photography) and simply ask Garry. That is, if you are sincerely interested in the truth and my integrity in reporting what I am seeing as accurately as I know how.

Regards,

Rhino I have no need to ask your peers if you are using Diamond Dock from the correct viewing position when i can see in your photo''s and video''s that you are not.

You seem to have a belief in there being such a thing as "truth".

It would be nice if we could simply discuss things and if someone criticises someone elses techniques or makes a contribution that others test the new idea and if they find some value then we could expect a change in technique.

What is so hard about using Diamond Dock as the manual says it should be and not filming in it at high angles?

BTW thank you for your last photo which appears to have been taken at the correct angle. I think from your words you understad the issue of the back ground color now.

But you clearly do not yet get the idea as to why you should not use a strong light so very close to the diamonbds for cut grading. If it offends you that I persist I will give up.

 

[Garry H (Cut Nut)]

Simple question Rhino:

When you are at a dealers office and looking at diamonds do you hold the stone you are considering under the dealers fluoro light to asses its cut performance? Or do you hold it under the lip of the desk and or turn away from the desk?

 

[Rhino]

Hey Senor,

Comments in bold.

Date: 8/9/2006 4:52:46 PM
Author: Garry H (Cut Nut)

Date: 8/9/2006 2:14:33 PM
Author: Rhino

To settle forever the issue of whether I am using the DD correctly or not why don''t you just contact any of the research gemologists at GIA and ask them? Point them to any of the material I''ve published (video or photography) and simply ask Garry. That is, if you are sincerely interested in the truth and my integrity in reporting what I am seeing as accurately as I know how.

Regards,

Rhino I have no need to ask your peers if you are using Diamond Dock from the correct viewing position when i can see in your photo''s and video''s that you are not.

Perhaps you have not seen the updated manual. I am not using it incorrectly. Never had.

You seem to have a belief in there being such a thing as ''truth''.

I do. At once perhaps I didn''t.

It would be nice if we could simply discuss things and if someone criticises someone elses techniques or makes a contribution that others test the new idea and if they find some value then we could expect a change in technique.

It would be nice if we can simply discuss things. I am all for contructive criticism, just not snide remarks.

What is so hard about using Diamond Dock as the manual says it should be and not filming in it at high angles?

I''ll forward you the updated manual in email. Garry ... in case you forgot I photographed diamonds in both positions (standing up and seated) in a past thread on this subject and showed quite plainly that there is no difference in the assessment.

BTW thank you for your last photo which appears to have been taken at the correct angle. I think from your words you understad the issue of the back ground color now.

Absolutely. In fact that photo was taken at the angle I always do. No different.

But you clearly do not yet get the idea as to why you should not use a strong light so very close to the diamonbds for cut grading. If it offends you that I persist I will give up.

Taking about diamonds and even offering constructive criticism doesn''t offend me. Suggesting I need remedial skills in reading and some of the other condescending language you use is just not cool and is offensive. Sure it may entertain some folks around here but how long would you stick around if all I did was insult your intelligence? I am for discussing the issues, lets just keep it civil and perhaps you and I will have a meeting of the minds. I am all for that. I believe we both have much to contribute which in the end will benefit the readers of this forum. And at the same token Garry ... if there is anything I have said to you that came off as sounding condescending or hurtful, my apologies as I never come here to this forum in that spirit or frame of mind.

Now lets have fun with this and continue to grow and learn.

Kind regards,

 

[rogue]

Date: 8/9/2006 4:01:18 PM
Author: Rhino

In an effort to further help your understanding Alj, here is a photograph I''ve taken of the same 2 stones I used above. BTW the leaker in these photographs is the identical stone I used in the video. The other stone in these photographs are of a 1.02ct I VS1 H&A stone. This photograph below demontrates Leo''s point above, however both the lighting environment and backdrop are changed now.

This lighting is diffused daylight fluorescent (taken under the GIA DD) and accurately depicts brightness. If this lighting were too strong and different temperature, then the H&A stone would take on the darker body appearance we were talking about previously. In this lighting we make the same assessments we''d see in natural diffuse daylight (outside on a cloudy day, in shaded sunlight, etc... see our vid on brightness for more comparisons) but this photograph IMO demonstrates what Leo is talking about above.... ie. Leakage shows up best when there is no light from the background. I took this photograph against a black background but I definitely prefer the neutral gray GIA provides with the DD as it does not cause any overexposure both in viewing and also in photography. I adjusted the brightness and contrast slightly on this image to better reflect what I am seeing but in these images (zoomed back and a macro shot) show plainly the effects of leakage when observed against a dark backdrop. It is easy to see that the H&A is the brighter diamond and highlights the view one would/should see in a diamond in these environments.

Hi Rhino, in both of these stones, a dark ring of sorts is visible (I''m assuming the second one is the leaky one though?) -- is there ever a stone where there is no dark ring on the inside of the table?

 

[Rhino]

Date: 8/9/2006 5:09:58 PM
Author: Garry H (Cut Nut)
Simple question Rhino:

When you are at a dealers office and looking at diamonds do you hold the stone you are considering under the dealers fluoro light to asses its cut performance? Or do you hold it under the lip of the desk and or turn away from the desk?

Good question! Actually I don''t look at stones in dealers offices anymore.

I have everything shipped and do my analysis here in our lab where the views are better and with more varieties.

However, if I am at a dealers office I''ll generally use whatever lighting they have realizing how the view I am seeing will translate to more normal circmstances. If you recall in my vid on the subject of brightness I cover diamond dealer lighting and the limitations of that environment (dependant on the backdrop). Also, if I know I''ll be visiting dealers I''ll generally have a pocket ASET and Ideal-Scope with me as well. Over the course of time a focus of my personal studies mate, was studying how reflector images translate to face up appearance and learning what I can and can''t determine by using them. Admittedly I had made some very expensive mistakes when I first started using a FireScope and I''m talking about any particular brand either but of diamonds in general.

Peace,

 

[Rhino]

Date: 8/9/2006 6:01:49 PM
Author: rogue

Date: 8/9/2006 4:01:18 PM
Author: Rhino

In an effort to further help your understanding Alj, here is a photograph I''ve taken of the same 2 stones I used above. BTW the leaker in these photographs is the identical stone I used in the video. The other stone in these photographs are of a 1.02ct I VS1 H&A stone. This photograph below demontrates Leo''s point above, however both the lighting environment and backdrop are changed now.

This lighting is diffused daylight fluorescent (taken under the GIA DD) and accurately depicts brightness. If this lighting were too strong and different temperature, then the H&A stone would take on the darker body appearance we were talking about previously. In this lighting we make the same assessments we''d see in natural diffuse daylight (outside on a cloudy day, in shaded sunlight, etc... see our vid on brightness for more comparisons) but this photograph IMO demonstrates what Leo is talking about above.... ie. Leakage shows up best when there is no light from the background. I took this photograph against a black background but I definitely prefer the neutral gray GIA provides with the DD as it does not cause any overexposure both in viewing and also in photography. I adjusted the brightness and contrast slightly on this image to better reflect what I am seeing but in these images (zoomed back and a macro shot) show plainly the effects of leakage when observed against a dark backdrop. It is easy to see that the H&A is the brighter diamond and highlights the view one would/should see in a diamond in these environments.

Hi Rhino, in both of these stones, a dark ring of sorts is visible (I''m assuming the second one is the leaky one though?) -- is there ever a stone where there is no dark ring on the inside of the table?

Hi rogue,

Excellent question (and your assessment is correct). Even in the rarest cut diamonds you will generally always get reflections of things obstructing light (hence some darkness). Plus we do not live in a symmetrical world. Lighting/reflections are generally always assymetrical with illumination that is generally always asymmetrical as well. Also keep in mind that diamonds are not static, ie. they''re always moving so you will not see that darkness constantly in the way you would in a GIA VG or Good steep/deep (like in that photograph and video). One particular stone that doesn''t show that darker feature under the table in a static face up view (with asymmetrical lighting) as much is the Eighternity. Here is a shot I have on the harddrive of this comparison under the same lighting. You''ll note less darkness under the table in diffuse lighting.

Thanks for the question.

 

[pricescope]

Date: 8/9/2006 3:13:04 PM
Author: Rhino
....
In environments where strong spot lighting exists ideal cut diamonds takes on a darker body appearance, however the flashes of light will generally always be stronger and happening at a greater frequency. You can clearly see this phenomena in each of the video scenes I''ve recorded. I''m attaching a photograph I just took in our store that is taken in spot lighting. In this photgraph you can plainly see the darker body appearance of the H&A stone. The leaky stone takes on a lighter apperance.

The reason for this doesn''t require a PHD in rocket science. It''s rather simple to understand when you understand how diamonds react/handle light.
...

Rhino, you''re talking about "darker body appearance" in strong spot lighting. What causes this effect, please?

 

[Garry H (Cut Nut)]

Date: 8/9/2006 8:26:58 PM
Author: Pricescope

Date: 8/9/2006 3:13:04 PM
Author: Rhino
....
In environments where strong spot lighting exists ideal cut diamonds takes on a darker body appearance, however the flashes of light will generally always be stronger and happening at a greater frequency. You can clearly see this phenomena in each of the video scenes I''ve recorded. I''m attaching a photograph I just took in our store that is taken in spot lighting. In this photgraph you can plainly see the darker body appearance of the H&A stone. The leaky stone takes on a lighter apperance.

The reason for this doesn''t require a PHD in rocket science. It''s rather simple to understand when you understand how diamonds react/handle light.
...

Rhino, you''re talking about ''darker body appearance'' in strong spot lighting. What causes this effect, please?

And while you are at it would you mind giving a full explanation as to why the leaky stone looks lighter please Rhino? I think you have been indicating a reason which is not one that I agree with.

 

[zhuzhu]

folks, we are not in high school anymore.......

 

[Shay37]

Jon, enjoyable video. I have found that a still camera is very hard to catch fire. (okay it drives me crazy) The video worked much better because you could rock the stones.

Only one slight criticism. This is partly for this video and partly for any new ones who will be closer specs; and thus, not as apparent which is which. Please, please, please, as a request from an anal steno, when you change locations, don''t change the diamonds around. First on the left and then on the right. Pick a side for your ideal, and let it remain there throughout the whole video. It''s a tiny little thing, but it did bug me a bit. With diamonds that have closer specs, I would have been driven completely nuts. It was a minor distraction in an otherwise delightful video. I know, I know, I''m nuts. Humor me.

shay

 

[Rhino]

Date: 8/9/2006 10:20:49 PM
Author: Garry H (Cut Nut)

Date: 8/9/2006 8:26:58 PM
Author: Pricescope

Date: 8/9/2006 3:13:04 PM
Author: Rhino
....
In environments where strong spot lighting exists ideal cut diamonds takes on a darker body appearance, however the flashes of light will generally always be stronger and happening at a greater frequency. You can clearly see this phenomena in each of the video scenes I''ve recorded. I''m attaching a photograph I just took in our store that is taken in spot lighting. In this photgraph you can plainly see the darker body appearance of the H&A stone. The leaky stone takes on a lighter apperance.

The reason for this doesn''t require a PHD in rocket science. It''s rather simple to understand when you understand how diamonds react/handle light.
...

Rhino, you''re talking about ''darker body appearance'' in strong spot lighting. What causes this effect, please?

And while you are at it would you mind giving a full explanation as to why the leaky stone looks lighter please Rhino? I think you have been indicating a reason which is not one that I agree with.

Hi Garry and Leo,

Perhaps Sergey could best explain the *why''s* to you better than I but my hypothesis is quite simple actually.

Based on the factual data we know about each stone, one of these are blocking backlighting (the H&A ideal) while the other stone is allowing the entrace of backlight through the pavilion. Since GIA/AGS zenith stones have minimal leakage these diamonds are generally only reflecting what is before them, with minimal entrace of backlight. Since stereoscopic vision is limited to see only what is shined into the directions of our 2 eyes, there are many internal reflections our eyes are not picking up. (The MSU scintillation demo comes to mind which allows you to actually see how many flashes of spectral light emanate from a stone). My theory is that the intensity of the flashes our eyes are not seeing are causing our vision to see only the results in the body of the diamond ... ie. when not observing bright intense flashes, we''re seeing the result in the body of the diamond which is strong contrast in the opposite direction. Ie. darkness.

Kinda similar to Leo''s graphics/vid but in Leo''s example we''re looking at the diamond as a whole go from light to dark while in the situation I''m explaining we''re observing the diamond go from showing strong intense flashes in direct light, to not seeing those intense flashes (when the diamond is tilted) and only the result of the stong contrast observed in the opposite manner... the darker body appearance.

This is a type of contrast I mention in our tutorial on fire that is different from the contrast that is generally observed in diffuse light environments. Ie. in diffuse lighting the contrast is generally caused from obstruction of light, while in direct light environments contrast is caused from bright intense flashes of light reflecting off of facet surfaces vs areas within the diamond wherein we are not observing those flashes. It is in those areas where the body of the stone takes on that darker appearance.

I hope I am making sense to you.

This phenomena can be observed not only in jewelry store direct lighting as I''ve demonstrated in both the photographs and video but this is easily visible in direct sunlight as well. I have some footage of the same two stones in mock rings and its easy to see this difference there as well. In fact in mock rings I think its even easier to see.

Hope this helps.

IMO, what''s important really is not so much in the understanding of the "why''s" (althought it makes for great research) but the fact that it is present and does exist. There are plenty of things we accept, observe and don''t fully comprehend yet we see and use the results of them daily.

Peace,

 

[Rhino]

Date: 8/10/2006 3:48:04 PM
Author: Shay37
Jon, enjoyable video. I have found that a still camera is very hard to catch fire. (okay it drives me crazy) The video worked much better because you could rock the stones.

As one who photograph''s diamonds regularly I totally hear ya on this Shay.

Only one slight criticism. This is partly for this video and partly for any new ones who will be closer specs; and thus, not as apparent which is which. Please, please, please, as a request from an anal steno, when you change locations, don''t change the diamonds around. First on the left and then on the right. Pick a side for your ideal, and let it remain there throughout the whole video. It''s a tiny little thing, but it did bug me a bit. With diamonds that have closer specs, I would have been driven completely nuts. It was a minor distraction in an otherwise delightful video. I know, I know, I''m nuts. Humor me.

shay

LOL... Consider yourself humored. I''ll be sure to pay attention to this on all future shooting. I''m certainly not looking to confuse.

I really appreciate this feedback Shay.

Kindest regards,

 

[Rhino]

Did that help Alj?

 

[pricescope]

Thanks, Rhino. I''m trying to reproduce this "dark body" phenomena.

When you filmed diamonds in direct sunlight, was it outside under the sky or inside by a window? Where were the sun, diamonds, and camera in relation to each other?