In spite of the similar looks, there are different benefits and drawbacks to these two technologies. Obviously, both can be used to indicate the light performance of diamonds and if you look at an Idealscope, you can see that it consists of the black lens and a red belt.
On the other hand, when you are looking at an ASET, you will see a blue, a red and a green belt. Both tools reveal areas of light leakage indicated in white (or black if it is not backlit), but the ASET image contains more information. Thanks to the lower green belt, the ASET is also able to highlight the intensity of light that is being returned to the eye.
Idealscope images are depicted on the left and ASET images on the right.
The answer is “it depends”. The ASET scope obviously provides more information with regards to the light performance of the diamond. However, it does take a little more knowledge to decipher what the individual colors mean and how they co-relate to a diamond’s optics. In general, the ASET is the preferred tool for evaluating fancy cut diamonds.
On the other hand, the simplicity of the idealscope brings certain lucidity to the table. You do not really need any gemological qualification to figure out which type of Idealscope images to look out for. Red is desirable and indicates light return while diamonds with too much white areas indicates problems with light leakage.
Which Is Better For Evaluating Light Performance?
Neither of the tools is black magic and both are highly useful. In my opinion, you should proceed according to the following. If you are buying an expensive piece of jewelry, it might be worthwhile to hire an individual appraiser who is familiar with ASET/Idealscope technology. Let them work with the ASET images and make him/her explain the findings to you.
However, if you are buying on your own and you want to see a little more than what a simple 10x jeweler’s loupe might tell you, an Idealscope is – pun intended – the ideal tool you should use. Either way, both scopes will offer you compelling information in a non-technical manner.
If you are buying diamonds online, you should always request Idealscope/ASET images on top of photographs or videos. This will enable you to scrutinize performance in more details.