A few months ago, I started to reverse engineering the main PCB. Having only my Galaxy S10 as a photography device, as usual I took the best photo I could with it, imported it in Paint.net and worked on tracing back the PCB pattern. However, despite the Galaxy S10 camera specifications to be quite good, the board being relatively big, after zooming in a bit here is the maximum details I could have:

Not impossible to work with, but rather difficult. I would often see myself confirming the PCB pattern by directly checking the board, which made the reverse engineering process tedious and quite inefficient. I decided it was time to update my photography method but as I didn't want to spend a lot of money, rather than buying a good camera with a stand I looked for an alternative and ended buying this:

This is a document camera, also known as a visual presenter. To put it simply, it's a digital version of an overhead projector. This one is a P30HD made by ELMO, a Japanese company specialized in document cameras. I got it for just 3500 yens on Yahoo Auctions and chose this particular model for a good reason: of all second hand document cameras I could find, this model has the most powerfull optical zoom (x16). Here is a list of all second hand document cameras I found with their respective main specifications.

The P30HD also has a HDMI output, an onboard screen, a D-SUB input and output port, a SD card/USB flash drive saving feature (need the remote to use it), a light and can be connected to a PC via ImageMate software (free proprietary software).

To give you an idea of the optical zoom performance, here is a short video demonstrating the zoom capability (recorded via ImageMate software).