DIY a light tent is easy, provided you have the necessary tools.
Just find a square box, cut the 3 sides, leaving some space near the edge, paste the holes with white paper and it's done!
This is how it looks like:
And this is the result:
Due to the thickness of the paper, the result is not so good. I have to actually expose the object quite long. I will replace the thick A4 paper with some thin white fabric instead in the future.