For my roasting work I wanted a stereo microscope to study the defect beans. With the internet it is easy to find school suppliers. I did not need a professional unit, one designed for school work was fine. I am in Canada so I was looking for a Canadian supplier to avoid customs.
I bought a CM51 from Carton Valley Microscopes. (www.carton.ca) (see in the sale section)
The unit is called a NSW-30T in the documentation. I think it has different labels depending on who is selling it.
I was looking for a wide field of view and with 10X the field is 23.0 mm. This lets me view about 6 beans at once. At 20X the field is halved which does nice closeup work on one bean.
I am also working on my roasting room now. The range hood vent is about half installed. I wanted to set up an area with good ventilation as well as a permanent place for the computer server attached to the roaster. I’ll post pictures of it when it is done.