Buying Recommendations — Portable Projector

Hi all. I am on the road several times weekly, running presentations with my Macbook Pro and Keynote. Occasionally there are technical issues, and the available projector on site is not working or won’t connect properly. This is a real problem. I would like to have a backup available. I have a sufficient portable speaker, so I’m primarily concerned with being able to see the slides and videos.

I understand the general advice is to buy a projector that will fit your room and lighting, but I don’t have that option. I’m looking for something that will be versatile in various settings and reasonably priced. Typically the audience size is 20-100. Unfortunately, the larger rooms seem to have the most connectivity issues, so I should get something to accommodate a larger group.