Originally posted by Class A Not having to lug around extra lenses in the bag and having to change them (sometimes loosing shots in the process) counts for something too.
True. Although as I mentioned elsewhere, you should also consider that the 18-250 will force you to miss shots as well because it does not have a wide enough maximum aperture, because its AF is relatively slow, because the focus ring is not as precise as that of a higher quality lens, because of the lack of quick shift, or even perhaps because you are that much less likely to have the camera with you than you might with a significantly smaller lens. Plus you have to accept that many of your shots will be compromised a bit in IQ over what is possible with higher quality lenses. As it happens, all of these issues are most pronounced indoors in low light.
Now frankly, if it were just a choice between a 18-55/50-200 combo and the 18-250, I might well choose the 18-250 too. Except for lack of quick shift (which is a pretty big exception, actually), all the potential "shot missers" I just described apply to any of the "consumer" zooms. Really, the main reason to do the two-lens kit would be financial: the 18-250 costs about twice as much.
It's primarily in comparison to primes that issues I mentioned become more significant. But of course, so does the extent to which you might miss shots with primes because you don't have the focal length you'd want on your camera, or perhaps *at all*.
I know it sounds trite, and I didn't buy into this at first either, but you really *do* start to learn to "see" differently with primes. Instead of bemoaning the shots you are missing because you've got the wrong focal length on, you start noticing opportunities for shots that wouldn't have even occurred to you if you were using the zoom. You'd be so busy taking the shots you *can't* take with the prime that you miss shots you could actually have taken with either lens.
Anyhow, not to say there aren't advantages to the 18-250. Obviously, there are. But they do come at a price that isn't always obvious.