The resolution is given by 1.22λ/NA. λ can be rounded to 500nm and the NA of a standard 20x objective is .4 giving 1.5µm. This is good because I was worried yo

The resolution is given by 1.22λ/NA. λ can be rounded to 500nm and the NA of a standard 20x objective is .4 giving 1.5µm. This is good because I was worried you caught me just making things up for the internet. A 40x with a .65 NA gives just under 1µm resolution. Resolution is also a slightly fuzzy spec depending on the audience. I go with the Raleigh criteria: You can't distinguish between two particles separated by less than the resolution distance. You can however, see particles much smaller than that, and there are many variations, most of which give you better resolution numbers. We occasionally use other specifications when we need to say we met a specific target. The standard objectives I am quoting are Olympus Plan Acromats, different systems have different tube lenses which cause you to get a different magnification out of the same objective. That is why the NA is the important factor. Otherwise I would just use a 1m tube lens and get 5x higher magnification numbers to report similar to what we see with the paper microscope.