Have used Keynote on several occasions - absolutely the best! I use a plain black background & my photos and images just pop! If there are type face issues, could save the presentation as a PDF, then open and present?
Also, when I used the installed projectors in various locations, found that I had to decrease the exposure, used levels in Photoshop. Worked wonders! I had noticed that some of my scanned images (graphite, ink, etc) were way to light. Darkened them a bit, I found a “magic” number in levels, ran a test or two, fabulous results.
The images may look a bit “flat” on the CPU, but projected - beautiful!
Best! “OC”