# Does the Rayleigh formula apply to electron microscopes or only light microscopes?

I am asked to determine the resolving power of both a TEM (transmission electron microscope) and a SEM (scanning electron microscope) and given the Rayleigh formula below.

$$Resolution=\frac{0.61\lambda}{N.A.}$$ Where $$\lambda=0.0039$$nm since the wavelength of an electron is $$0.039$$ angstroms and $$1Å=0.1$$nm.

I am also told that the N.A. the numerical aperture for the TEM is $$0.01$$

So, $$Resolution=\frac{0.61(0.0039nm)}{0.01}=0.24nm$$

For the SEM I am not given the N.A. but I am told that the resolution is $$10$$nm

My problem is if I use the Rayleigh formula $$Resolution=\frac{0.61\lambda}{N.A.}=10nm$$ I get $$N.A.=0.0002379$$ Which would imply that the aperture for the SEM is greater than that of TEM since N.A for TEM is $$0.01$$ and SEM is $$0.00023$$ $$0.01>0.00023$$.

My problem is that I'm told the greater the aperture (smaller value of aperture) the greater the resolution but as you can see from the equations above this doesn't seem to make sense, The only explanation I can think of is that the Rayleigh formula does not apply to electron microscopes. Any advice would be greatly appreciated thank you.