Is there a curve of focal lengths and zoom that flattens out? I have a 28-300 as my only real zoom, and the difference between 100 and 200 seems alot more than between 200 and 300. And today, my friend just got his Sigma 50-500, and I was ready to be like "okay, 500 is gonna be incredible!"... So I set the lens to 300, which is what I am used to, then cranked it up to 500!!... and the increase wasn't as much as I suspected.
So now I am wondering, is the difference between 300 and 500 less than between 100 and 300? Do zoom lenses magnify in a less and less ration as you go up higher and higher? I hope this is making sense.