Light boxes/tents can be a great help with jewellery photography as the diffused lighting helps give more even toning and colour. One thing to note though, is that by diffusing your light source you are also going to lose stronger light points that create sparkle. This works when you want to show more details without light obscuring them (diffused light is used for the GISA photomicrographs for this reason) but it will also take away most, if not all, of the 'sparkle'.
For this reason professional jewellery photographers use what they call a "Sparkle Box".
This is basically a light box or tent with the addition of some strategically placed small LED lights INSIDE the box. This way the pieces get mostly diffused lighting with all those benefits without losing the lovely sparkles.
You could easily add your own LEDs to one of the above DIY setups to get good results.
Gemmology Institute of Southern Africa / African Gem Society / Gemmological Society of South Africa
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