interpreting ASET photos

[slg47]

Hi everyone-I was wondering about the effect of different photography on ASET images. For example, some vendors use black background, some use white, some photos appear more blurred while others are very 'crisp' looking. I saw one that looked (to me) like the diamond was way too far into the ASET scope because it was overly dark red (or this could have been another problem?) What should consumers keep in mind when interpreting ASET photos?

 

[Paul-Antwerp]

Good question.

First and foremost, it is important to have some kind of reference. In rounds, given their straightforward faceting pattern and the historical concentration of cutting near one specific area, it is relatively clear what to expect in an ASET-pic and to observe the deviations.

In fancy shapes, it is another story however. Never having studied pear-shapes in detail, for instance, I can look at the ASET-pic of a pear-shape without having any clue. Sure, I can see the areas of various colours, but I do not have a reference-pattern to really assess it.

Interpreting ASET-photos of various vendors is truly a minefield. To start, it is technically a very difficult picture to take.

Given the importance attached to the various colours, it is essential to have the ASET-scope placed exactly at the correct position versus the diamond. Unfortunately, most vendors do not understand the theory completely and, to their defense but unfortunately for the industry, even the ASET-camera supplied by AGS has an inherent flaw which creates incorrect pictures.

This results into many pictures (especially of fancy shapes) being taken with the diamond way too far into the ASET-scope. This creates the appearance of contrast-patterns that in reality do not exist, more red than in reality, and green areas in certain areas of light leakage.

Given the difficulty of photographing ASET's, it is very frustrating for the photographer and him or her often not being a gemologist, so possibly not really understanding the meaning of the various colours and definitely not having an expected reference-pattern, logically often leads to pictures that do not represent reality.

In our case, our photographer is very lucky, since we cut both our shapes towards a specific configuration. He thus knows that something is wrong, either with the stone or with the photo-setup if he gets unexpected patterns. And generally, we find the fault in the setup.

Live long,

 

[ChunkyCushionLover]

1) Static image is not as good as an ASET video or simulated ASET video. In some cases the static faceup image may not tell the whole story.
2) Black background not as good as white for seeing leakage and obstruction
3) Centering the diamond and tilt is important. Especially in pear shapes and for seeing things like bowtie in pears and cushion shapes etc.
4) Watch out for things like blue around the edges or the absence of blue. (Like James Allen's setup). This can indicate a poorly modified setup that is inaccurate.
5) When possible compare .gem file simulated to the photographed ASET to determine tilt, and any photographic anomalies
6) Step cuts are difficult to judge by ASET, multiple images including Idealscope and photographs are useful, dynamic images are much more indicative.
7) AGS uses 30 degree cone for obstruction(blue) it has been argued that perhaps this puts the viewer closer than optimal for an average head size(150cm). On the other hand if using their head size which is 130cm it is near the normal viewing position. The obstruction seen in ASET30 and ASET40 gives a good guideline for which diamonds will be potentially brighter than others at close viewing distances.



(Eventually Obstruction should have its own PS page and a full size version of this figure can be included)

 

[Karl_K]

The biggest thing to keep in mind is there is no one image that tells you everything there is to know about a diamond.
I like other images and video if I can get it to validate my interpretation of the ASET image.
Having someone that knows high performance diamonds and has a good tract record of selecting and or producing them look at the diamond is also important.
Then once I get the diamond I do my own evaluation to confirm everything.

How much information makes one comfortable with the purchase will vary from person to person.
It is my opinion that one needs to be comfortable with the item and the sale environment before turning over the money.
ASET images are one tool that can be used to reach that level but it should not be the only one.