For a good many years, I went back and forth between megapixels and millimeters trying to get more reach on my critter friends.
Just when I had concluded that the better option was more millimeters—and manufacturers were starting to make them more affordable—along came an optics wizard for whom I have much respect, advising users of his company’s products to “crop to zoom.”
That advice left me lacking reach on some critter photo opportunities, but fewer than I would have guessed. And on the ones for which I’ve had enough reach, the results have been extremely pleasing; so much so that I don’t rue the ones that are out of reach.
A bigger plus is that the lens is a zoom that shoots like a prime and can handle any subject matter, unlike many dedicated birding lenses, which are one-trick ponies.
Don’t get me wrong, though . . . I’ll be all over a teleconverter if a compatible one ever appears!