I know that the bigger the telescope aperture, the more photons you can collect, and the fainter the objects you can see. I also know that the bigger the telescope, the smaller the diffraction disc of a point source imaged with it, and therefore the greater the angular resolution (i.e. the sharper the images and the better your ability to see detail in them). When we give advice to prospective telescope buyers in this subforum we emphasize that magnification is nothing, and aperture is everything (along with a sturdy mount ). I would certainly agree that the ability to zoom in on an object by some ridiculous amount is useless if there are no features to see due to inadequate resolution, the image is too dim, and the field of view is too narrow to provide comfortable (and sensible) viewing of the object. However, I am interested in the role magnification plays in imaging with professional research-grade telescopes. You don't hear that word magnification used much. All that seems to matter is that you have a large enough primary mirror. We see Hubble images of galaxies in which individual stars are resolved. Surely this depends upon more than just the diffraction limit. For if two point sources are nicely resolved by the Rayleigh criterion, but their physical separation on the image plane (i.e. the detector) is so small that our eyes cannot determine that they are distinct, then what use is that? Sure, one could always "zoom in" on the image itself, but only to a limit. If two point sources have a subpixel physical separation on the detector, then that suggests you've made a poor choice of plate scale. The plate scale is determined by the effective focal length of the telescope optics. You want to choose it such that your object takes up a decent amount of the detector area. Isn't that what angular magnification does? You are choosing your effective focal length such that you're "zoomed in" on this object by a sensible amount (i.e. the angular size of the image is suffcient). So these telescopes do have to provide a certain amount of "magnification*." Am I right? *The only danger is in talking about that to the layperson and implying (incorrectly) that that magnification is the primary purpose of a telescope and is what allows us to see these amazing Hubble images (e.g. of a galaxy with individually-resolved stars), without pointing out that we could just as easily have a crappier telescope that shows an equally magnified image of said galaxy that looks like nothing more than a blurry mess due to insufficient angular resolution. Again, am I right? Comments and corrections welcome.