How to Use Ideal Scope to Identify Light Leakage

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February 5

“I’m shopping for a diamond engagement ring and want to know how to interpret Ideal Scope images. I’m convinced that I want a hearts and arrows diamond."

"I’ve read Brian Gavin and James Allen reviews. It seems that James Allen True Hearts Diamonds offer a good balance of quality craftsmanship and price."

"I understand that there might be some slight variances in the hearts patterns. I’ve looked at quite a few ideal cut diamonds in local jewelry stores lately. I’m not so certain that I would be able to discern the difference between the Top 1% and the Top 0.001% of rounds (as you put it in one of your articles)."

Ideal Scope Reference Chart.

Ideal Scope Reference Chart.

"I’m thinking that anything in the Top 1% has got to be pretty darn good! There is one thing stopping me at the moment. James Allen doesn’t appear to provide ASET Scope images for their diamonds."

"Are James Allen’s Ideal Scope images sufficient to determine whether a diamond exhibits great light return? By the way, I’m looking for round ideal cut, H-I color, VS-2 clarity and higher, priced up to 10k.”

How to Use Ideal Scope Images:

Place the diamond securely in tweezers to use an Ideal Scope, view it through the scope in the table face-up position, backlit with an ambient light source. It's essential to use a light source that is not too bright to avoid over-illumination that might seem like leakage.

James Allen Ideal Scope images provide an in-depth view of what each diamond looks like when viewed through an ideal scope. The imaging systems that Brian Gavin and James Allen use are professional grade and create a consistent lighting environment.

Garry Holloway developed the handheld Ideal Scope to help people judge the degree of light leakage. The fact of the matter is that all diamonds leak light to some degree. Obviously, some diamonds leak more light than others.

You can use the Ideal Scope reference chart above to familiarize yourself with the different grading standards. And of course, you can purchase an Ideal Scope on that website for next to nothing.

James Allen Ideal Scope Images:

James Allen Ideal Scope Image Tutorial.

James Allen True Hearts Diamonds.

James Allen Ideal Scope images are provided for their True Hearts diamonds. You can view the ideal scope image by placing your mouse over the red-colored icon of the arrows pattern of the diamond featured in the lower right-hand corner beneath the video.

The James Allen ideal scope image provided for this 1.31 carat, I-color, VS-2 clarity, James Allen True Hearts diamond looks excellent. There are some minor variances in the hearts’ pattern. Most notably, the heart located in the relative seven o’clock position is a hint smaller than the rest.

But if you direct your attention to the high-resolution video of the diamond, you can see that the diamond sparkles like crazy! The 40.8 degree pavilion angle is producing a high volume of light return.

The 34.3 degree crown angle is producing a virtual balance of brilliance and dispersion. The 77% lower girdle facet length is producing broad-spectrum sparkle. This diamond clearly offers great visual performance!

The ASET Scope is intended to help us determine where in the room a diamond is gathering light from, and provide a visual representation of how evenly light is being reflected throughout the facet structure of the diamond.

A skilled observer can also use an ASET Scope image to determine if the diamond is leaking light. Thus there is some crossover between the two types of reflector scopes. Suffice to say that there is a lot that you can tell by evaluating the James Allen Ideal Scope images provided for each James Allen True Hearts diamond.

Avoid the Infamous Ring of Death:

Ring of Death as seen through an Ideal Scope.

Ideal Scope Reveals Ring of Death.

Here is a file photograph of an ideal cut diamond, which shows a degree of light leakage in the Ideal Scope image that borders on the classic “ring of death” that you want to avoid.

The diamond is graded with an overall cut grade of AGS Ideal-0 and is being offered by another vendor as a top-of-the-line diamond, handpicked by their experts for its exceptional light performance.

Say what?!?! I’ll admit that this isn’t quite a full-blown “ring of death” but it’s not exactly a “ring of life” either! The diamond has a pavilion angle of 40.8 degrees, and this would normally produce a high volume of light return.

However the crown angle of 35.9 degrees is too steep, and most likely the upper and lower girdle halves have been cut too steep. That is causing the diamond to leak light under the table facet.

Consequently, this is the type of Ideal Scope image that should cause you concern. Because this “ideal cut diamond” is not going to provide the volume of light return and incredible sparkle factor that you’re looking for.

James Allen Review: AGS 104084159033

James Allen True Hearts Diamond Review.

James Allen True Hearts Diamonds.

As you can see, the James Allen Ideal Scope image provided for this 1.29 carat, H-color, VS-2 clarity, James Allen True Hearts diamond also looks great!

The ideal scope image is nice and bright! Showing a lot of red that is evenly distributed throughout the diamond. There aren’t any large areas that are translucent or white, thus there are no indications of substantial light leakage.

The black areas indicating contrast are even. The hearts’ pattern appears to be very nice, based upon the hearts image provided on the diamond details page. The 40.8 degree pavilion angle will produce a high volume of light return.

The crown angle of 34.0 degrees is a little shallower than I prefer (34.3 – 34.9 degrees) and this is likely to produce a hint more brilliance (white sparkle) as opposed to a virtual balance of brilliance and dispersion (colored sparkle). However probably not so much that most people would notice.

The combination of the higher degree of optical precision that results in the hearts’ pattern, and the 75% lower girdle facet length, should produce broad-spectrum sparkle.

That is the sparkle that is larger in size, bolder, brighter, and more vivid, than what would be exhibited by the diamond if the lower girdle facets were in the range of 80%. No doubt this is going to be a beautiful diamond.

James Allen Ideal Scope Images: AGS 104084159027

How to Evaluate James Allen Ideal Scope Images.

James Allen True Hearts Diamonds.

This 1.328 carat, H-color, VS-2 clarity, James Allen True Hearts diamond exhibits another great ideal scope image. Needless to say, it’s going to be a great-looking diamond! The pavilion angle of 40.5 degrees is a hint less than I’d like it to be.

I prefer that the pavilion angle be between 40.6 – 40.9 degrees. But it doesn’t seem to be having any negative impact upon the diamond in this instance.

The Ideal Scope image looks great, there are no indications of substantial light leakage. Remember that all diamonds leak light to some extent.

What I’m seeing in this diamond is perfectly normal for a high-end ideal cut. The 34.4 degree crown angle should produce a virtual balance of brilliance and dispersion.

The hearts’ pattern looks quite good, very even. Thus combined with the 77% lower girdle facets, it should result in broad-spectrum sparkle that is larger in size, bold, bright, and vivid in appearance!

James Allen True Hearts Review: AGS 104084159022

James Allen True Hearts Review

JA-TH Ideal Scope Image

The ideal scope image provided for this 1.39 carat, I-color, VS-2 clarity, James Allen True Hearts diamond also looks great! The hearts pattern exhibits minor variances in the size and shape of the hearts.

There is a bit more room around the point of the heart located in the two o’clock region, this indicates very slight differences in the length of the lower girdle facets and the indexing of the facets as they were polished onto the surface of the diamond.

This diamond does not meet my selection criteria to be classified as a “hearts and arrows diamond” but the hearts’ pattern is also much better than what I’d expect to see in the average ideal cut diamond.

Thus it falls into the middle ground from my perspective. The 40.7 degree pavilion angle should produce a high volume of light return, the ideal scope images certainly indicate this to be the case. The crown angle of 34.1 degrees is a smidge shallow, likely to produce a bit more brilliance.

Remember that in a perfect world, I’d like to see the pavilion angle be between 40.6 – 40.9 degrees. The crown angle would be between 34.3 – 34.9 degrees. This tends to produce a high volume of light return, and a virtual balance of brilliance and dispersion.

Ultimately however there is a lot that we can tell about a diamond using the James Allen Ideal Scope images, and this insight must be taken into account along with the proportions. By the way, the 76% lower girdle facet length should produce broad-spectrum sparkle, the hearts’ pattern is uniform enough to achieve this goal.

Free Diamond Concierge Service:

I hope that you enjoyed this article about interpreting James Allen Ideal Scope images. There are some great diamonds featured on this page for you to choose from. The client to who I wrote this response via email has already selected the diamond that he wanted of the group presented, the rest are up for grabs!

Please take advantage of our free Diamond Concierge Service if you’d like help finding a diamond, or simply want a second opinion on some diamonds you’re considering.

The service is “free” for consumers because I’m compensated for my time by way of affiliate agreements that I have with various online vendors. The great thing about this arrangement is that it costs you nothing.

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About the Author

Dive deep into the glittering world of diamonds with Todd Gray, the CEO of Gray Matter Development, LLC. Todd has 35+ years of experience as a diamond buyer and trade consultant. He ghostwrites content for several online vendors and is an avid Freediver, currently exploring the Cenotes of Yucatan, Mexico. Dive into brilliance with Todd Gray!