Are there any photos documenting the negative aspects of a "Steep Deep"

[Garry H (Cut Nut)]

Date: 11/19/2009 5:29:37 AM
Author: Serg

Date: 11/19/2009 2:36:06 AM

Author: Garry H (Cut Nut)

Date: 11/19/2009 2:27:46 AM


Author: kenny

Date: 11/19/2009 1:43:33 AM



Author: Garry H (Cut Nut)




. . . it is a concept from physics that if light can go in and out one way - the opposite must also be true.

Garry, would that also mean that light entering the pavilion would conceal the darkness problem with a steep deep?




Rhino, could you photograph a steep deep next to a well cut round, then take another pic backlighting the steep deep''s pavilion to make the darkness go away?

Yes Kenny, You can see a reflection of the light on crown facets on David''s photo - clearly that light is able to illuminate the pavilion.

re:You can see a reflection of the light on crown facets on David''s photo - clearly that light is able to illuminate the pavilion.


It is not clear for me at all.

Crown angle is 36.5 degree.

angle between viewer direction and crown facets( in vertical plan ) is 53.5 degree

so source of light ( what reflected from crown table) has 17 degree from girdle plane in Crown hemisphere !

of course Pavilion could catch light from upper hemisphere too, but statements like ''clearly that light is able to illuminate the pavilion'' are misleading

( Even ASET , IS are not very helpful to reject diamonds what could redirect light from upper hemisphere to eye by Pavilion facets)

Sergey the reflection is off the upper girdle facet wich should be 43 degrees. So the angle to the crown from the light is 4 degrees.
The ray I placed is 5 degrees above the horizontal plane.

 

[Serg]

Date: 11/19/2009 7:13:30 AM
Author: Garry H (Cut Nut)

Date: 11/19/2009 5:29:37 AM

Author: Serg

Date: 11/19/2009 2:36:06 AM


Author: Garry H (Cut Nut)

Date: 11/19/2009 2:27:46 AM



Author: kenny

Date: 11/19/2009 1:43:33 AM




Author: Garry H (Cut Nut)





. . . it is a concept from physics that if light can go in and out one way - the opposite must also be true.

Garry, would that also mean that light entering the pavilion would conceal the darkness problem with a steep deep?





Rhino, could you photograph a steep deep next to a well cut round, then take another pic backlighting the steep deep''s pavilion to make the darkness go away?

Yes Kenny, You can see a reflection of the light on crown facets on David''s photo - clearly that light is able to illuminate the pavilion.

re:You can see a reflection of the light on crown facets on David''s photo - clearly that light is able to illuminate the pavilion.



It is not clear for me at all.


Crown angle is 36.5 degree.


angle between viewer direction and crown facets( in vertical plan ) is 53.5 degree


so source of light ( what reflected from crown table) has 17 degree from girdle plane in Crown hemisphere !


of course Pavilion could catch light from upper hemisphere too, but statements like ''clearly that light is able to illuminate the pavilion'' are misleading


( Even ASET , IS are not very helpful to reject diamonds what could redirect light from upper hemisphere to eye by Pavilion facets)

Sergey the reflection is off the upper girdle facet wich should be 43 degrees. So the angle to the crown from the light is 4 degrees.

The ray I placed is 5 degrees above the horizontal plane.

re:

Garry,
it is not enough( even for 43 degree) . these rays intersect in 200-300 mm from diamonds
light source could be just in 100mm from diamond

again you do not know exactly pavilion angle,star facets ,diamond position and camera. it could easy reduce 5 degree. You can not say" clearly that light is able to illuminate the pavilion"

you can say " light could be able to illuminate the pavilion"

 

[rockabee]

Date: 11/19/2009 1:43:33 AM
Author: Garry H (Cut Nut)

Date: 11/18/2009 3:35:38 PM
Author: Rockdiamond
HI Garry,

As a photographer, I am very interested int he subject of ''Backlighitng''- which is by no means something we work to achieve.


That subject really deserves it''s own thread.

David does this help you understand the issue?
I have posted things like this before - it is a concept from physics that if light can go in and out one way - the opposite must also be true.
So if you had a light source where the strong ray is going out - then more about 60% of the light would go out the pavilion in the area just inside the table in that position.

fascinating thread. does this then mean that all else equal, we should avoid settings that cover up a significant portion of the sides of the diamond? i understand that in general you are not going to get spot lighting hitting the sides of the stone, but it stands to reason that if the side of the stone is more fully exposed, more light could pass through it and then bounce out the front. i mean, to be honest most rings are viewed on a tilt from light sources anyways: diamond table perpendicular from the floor when hands are down by side or you''re holding a drink or something. or there is a floor lamp and diamond is shown table up, parallel to floor but perpendicular to light source, etc.

this could be a topic for another thread unless i phrased my question as "will exposing more of a diamond mitigate effects like steep deep"?

 

[Laila619]

rockabee,

Good question. It is why I would NOT bezel a stone. I have seen them go darker in a bezel. Even when cut well.

 

[Rockdiamond]

HI All,
I''m clear on the fact that a deep diamond can have a dark center. It''s also likely that it''s spread will suffer.

Garry, I am a "hands on" kind of guy. I have little need to understand the physical reasons behind why a deep diamond looks dark- but a great need, as a grader and dealer, to be able to visually identify problem stones due to dark centers.
IMO, the best understanding will be achieved if there are photos that better show this dark area.
Then people will know what to look for.


Sergey- thanks yet again.
"Backlighting" seems to be some sort of "red herring" that gets thrown up to divert attention from the issue at hand

 

[Garry H (Cut Nut)]

Date: 11/19/2009 2:42:08 PM
Author: rockabee

Date: 11/19/2009 1:43:33 AM

Author: Garry H (Cut Nut)

Date: 11/18/2009 3:35:38 PM

Author: Rockdiamond

HI Garry,


As a photographer, I am very interested int he subject of ''Backlighitng''- which is by no means something we work to achieve.



That subject really deserves it''s own thread.

David does this help you understand the issue?

I have posted things like this before - it is a concept from physics that if light can go in and out one way - the opposite must also be true.

So if you had a light source where the strong ray is going out - then more about 60% of the light would go out the pavilion in the area just inside the table in that position.

fascinating thread. does this then mean that all else equal, we should avoid settings that cover up a significant portion of the sides of the diamond? i understand that in general you are not going to get spot lighting hitting the sides of the stone, but it stands to reason that if the side of the stone is more fully exposed, more light could pass through it and then bounce out the front. i mean, to be honest most rings are viewed on a tilt from light sources anyways: diamond table perpendicular from the floor when hands are down by side or you''re holding a drink or something. or there is a floor lamp and diamond is shown table up, parallel to floor but perpendicular to light source, etc.



this could be a topic for another thread unless i phrased my question as ''will exposing more of a diamond mitigate effects like steep deep''?

That is a really good thing to do with a not so well cut diamond.
The better the cut the less the advantage face up - but from say a 45 degree side view position it does help.

 

[Rockdiamond]

An Example:

I was able to coax this photo out of a badly cut stone by traditional standards..
I folded a piece of white paper around this diamond, and shielded light from above, best I could- the room was normal daylight, shouthern exposure.
Macro lens close up photo

This is a real photo of a diamond, a really bad case of dark center.

There's no way this diamond could ever dream of achieving "EX" cut grade- it's a fancy color, for one and the symmeter is only "fair" A large 63% table.


We could find a lot of reaons to call it badly cut.

 

[kenny]

Rockdiamond coming from you this is a very surprising pic.
It is much more out of focus than zillions from your website, www.diamondsbylauren.com .
The lighting is totally different too.
Why not use your usual set up?
Were you not trying to make this diamond look as beautiful as possible for some reason?
Based on www.diamondsbylauren.com I though you used only one glamorous lighting set up.

Please place this diamond in the photography set up that you use to shoot the typical pic on your www.diamondsbylauren.com site.
Seriously, I'm curious how beautiful of a glamor shot you can get of this same horrid diamond.

Also what are this diamond's specs?

Depth %
Table %
Crown angle in degrees
Pavilion angle in degrees

 

[kenny]

David, this is clearly not your usual lighting set up.

Why didn't you use your usual same lighting set up as in this pic randomly selected from the first page of www.diamondsbylauren.com ?

Notice the front of the tweezers is dark, proving you are lighting the pavilion.

 

[Rockdiamond]

AS I mentioned, it was difficult to coax the darkened center out of the diamond.
Basically, I pinched the diamond in the white paper so that there was no light allowed into the pavilion.
This photo was take a second later after i loosen the pinch, allowing light to some light into the pavilion.
Still a dark center but not nearly as dramatic.
Agreed that a nice photos of the diamond showing it under lighting for comparison is a good idea.

BTW, this round damond is NOT on our site. I found the phtos of it useful for the demonstration.

It''s a Fancy Colored Diamond Grading rpeort- - I can have a sarin run to get ca/pa

 

[kenny]

Date: 11/22/2009 6:29:52 PM
Author: Rockdiamond
AS I mentioned, it was difficult to coax the darkened center out of the diamond.

Basically, I pinched the diamond in the white paper so that there was no light allowed into the pavilion.

This photo was take a second later after i loosen the pinch, allowing light to some light into the pavilion.

Still a dark center but not nearly as dramatic.

Agreed that a nice photos of the diamond showing it under lighting for comparison is a good idea.


BTW, this round damond is NOT on our site. I found the phtos of it useful for the demonstration.


It's a Fancy Colored Diamond Grading rpeort- - I can have a sarin run to get ca/pa

For sale or not, since you have this diamond please use your standard www.diamondsbylauren.com set up and lighting to take the most flattering pic you can of it.
Pretend you were selling it.
We know you can.

It would be informative to see how beautiful the pavilion-illuminating set up you use to photograph the diamonds on www.diamondsbylauren.com can make this badly cut diamond look.
You have already demonstrated how dramatically better letting light into the pavilion of this diamond can improve the darkness under the table.
Let's take it all the way.

 

[arjunajane]

I agree Kenny 100% that it would be "illuminating" if David could photograph this diamond in his usual technique.

David?....

 

[Garry H (Cut Nut)]

bump

 

[ChunkyCushionLover]

Date: 11/23/2009 2:14:04 PM
Author: Garry H (Cut Nut)
bump

Hey Gary,

I too am looking forward to seeing the pavillion lit backlit photograph for that stone above, it would be educational to see how much of a difference the position of the light source can make in a diamond photograph. Lets hope RD has enough respect for education, this thread, and the PS community to provide it.

CCL

Threadjack: Are those 4 main's (Cushion 2) you showed me on Octonus ready for production yet? Where will they be available?

 

[Garry H (Cut Nut)]

Date: 11/23/2009 3:21:38 PM
Author: ChunkyCushionLover

Date: 11/23/2009 2:14:04 PM

Author: Garry H (Cut Nut)

bump

Hey Gary,


Threadjack: Are those 4 main''s you showed me on Octonus ready for production yet?


Regards,

CCL

there are several newer and seemingly better variants being cut as samples

 

[Rockdiamond]

I did take more photos of the diamond in question, and I will post them.

Before I do: Kenny and CCL- seeing as how you're both very open minded, unfailingly polite and easy to discuss these matters with, let me ask you both to first to show me a photo of a diamond taken the way you like.
Garry I'd ask you the same thing. Or anyone else.
Actually it will be very interesting to see what people want to see in a photo.
I want to see photos showing what Kenny, CCL and Garry, consider the "correct" way of photographing a diamond, making sure not to allow light into the pavilion.
No that it's going to change how I take photos- but at least I'll know what those guys expect.

 

[kenny]

I have 100% artistic freedom in photography because I'm not selling.
If I was selling I'd NEVER do this.
Rather, I'd feel an ethical responsibility to not mislead customers into believing that my diamonds looks supernatural.

Here is the set up for the pic that follows.
I place colored objects between the diamond and the lens (the camera is behind that hole in the white cardboard).

 

[kenny]

When taking the pic I push the lens against the hole in the cardboard.
It is just pulled away to show the set up.

 

[kenny]

Here''s the results.
Very cool and pretty, but hardly objective or representative as a sales pic.

 

[kenny]

Imagine if vendor pics looked like this.
It would be absurd.

 

[kenny]

If selling I'd likely use lighting something like this.
Same set up as above but with the colored objects removed.

I'd also modify the set up so no light whatsoever could enter the pavilion.

 

[Rockdiamond]

Very pretty photos Kenny!
We'd never take photos like the colorful ones- they look nothing like mine- and you're correct, they'd be horrible to use to try and represent certain aspects.
I could clearly see the facet pattern, but all the colors are distracting.



BTW- What I asked of you was photos you do feel are better, not those that are less representative.,

 

[kenny]

Date: 11/23/2009 4:59:05 PM
Author: Rockdiamond


BTW- What I asked of you was photos you do feel are better, not those that are less representative.,

Go look at Whiteflash and Goodoldgold. (not GOG's dark field pics that are to point out inclusions)
Also, my last pic is pretty close to a lighting set up I'd consider if I was selling.

 

[Rockdiamond]

Kenny, I''ll bet you know how to copy a photo you like and post it here as opposed to just saying go look at other sites.
Please pick one you like and post it.

The last photo you posted is really great.
I''m certainly tempted to try your methods out!

How did you prevent light from entering the pavilion in your photo- I know that really bothers you.

 

[kenny]

It's not about what "bothers me".
It is about lighting techniques that make diamonds look better-cut than they really are.

My technique of placing the flood behind the diamond to illuminate a white surface in front of the diamond would require something to block direct light from entering the pavilion.

If I was selling I'd try other lighting techniques, like this dome, that only allows soft even directionless light in only from the top.

 

[Rockdiamond]

I certainly have new respect for your photographic prowess Kenny. I like your photos a lot. Are you saying no light was entering the pavilion in the photos you posted?

Interesting dome concept.

What about photos currently online with no light entering the pavilion?

 

[kenny]

Light WAS entering the pavilion.
See my set up.

It is clear some could enter the pavilion.

 

[Rockdiamond]

I understand Kenny.
Let''s see these photos that yoyu like that have no light entering the pavilion.
While we''re at it, could you explain how it''s physically possible?

 

[kenny]

RD I intentionally used those (inserted color) pics to show there are many many ways to use photography to make diamonds look supernatural.
I think sellers should not do that.

With your backlighting you do that to a much greater degree than the PS vendors, and you have been called onto the carpet for it for years.

 

[kenny]

Stop dancing around.

Just make your point.

Clearly you want me to find a pic so you will argue, "blah blah blah, you can't PROVE there is no backlighting, blah blah blah".

Dancing.