As I guessed, my 18-200mm comments yesterday stirred up a firestorm. Most of it was in defense of the maligned lens, citing things like no sensor cleaning, not carrying extra lenses so no bag to deal with, being free to do any type of photography on the spur of the moment, "better" DOF capabilities, and so on.
My personal observation was best summed up by one of you in this comment: "I've come across so many people saying that their DX camera kit does not produce any better photos than their previous compact." Which ironically, leads them to want an FX body (hey, keep going upstream until you catch a fish).
So right up front let me say that if you really know what you're doing and you really think the 18-200mm is your answer, then don't let what I write stop you. The 18-200mm is a good lens, perhaps even very good still (time exposes weaknesses in any product). But it's not a solution for everyone, and the all-in-one mentality starts you down the compromise path that often leads to casual snaps instead of photographs. The primary point I was trying to make is that if you go far enough down the compromise path (single thing to carry, light, small, convenient), then perhaps you're better off looking beyond downgrading your DSLR via a superzoom.
People often get caught up in the marketing messages ("DSLRs provide better image quality, are faster") and don't look enough to the practical application. For some, there's even justification at work, as they don't want to explain to their spouse why they spent so much for that D300s and seven lenses, but are taking a modest price compact or bridge camera on vacation with them. Most of the responses I received were defensive in nature, and many of them had some aspect of that last point to them.
But again, if you think you know your needs better than I do (and you should), bring what you want to on your vacation. As I noted earlier in the week, this little mini-series of articles was more about trying to pre-answer the question that I get from so many this time of year. People asking the "what should I bring" question don't understand their needs. At that level of photographic understanding, a competent compact or bridge camera may be a better choice than running up the credit card to buy a DSLR and 18-200mm lens (just to remind everyone, a D5000 and 18-200mm represents an expenditure of US$1400 at the moment).
This last point starts to drive home the cost of convenience: a D5000 with the two kit lenses (18-55mm VR, 55-200mm VR) costs about US$1000. So the cost of the convenience of not changing a lens during your trip is US$400. Worse still, the 18-200mm isn't as good as the 55-200mm in that range, so you're paying a slight penalty in image quality, too. I'd also argue that having to switch lenses to go from wide/normal to telephoto also makes you think a bit about what you're trying to do, as you don't swap the lens unless you perceive you need to.
That out of the way, let me take the defenses one by one:
- No sensor cleaning needed. Maybe. Personally, I haven't found that much difference between swapping a lens every now and then and not on the recent cameras with the anti-dust shake function. But worse, what happens if you anticipate no dust problems and encounter one on the road? The 18-200mm user who thinks no dust can get in there is going to have no way of dealing with it. Be prepared.
- No carrying extra stuff. Yes, one lens and one body means that you can just hang the camera around your neck and don't need a bag to hold other items. Be careful, though. When you slip off the trail or steps and the camera goes swinging, it just might hit something. Usually it's the lens that sustains the real damage in such situations. But you only brought one ;~(.
- Spur of the momentness. Does carrying an extra lens or two really shut this down? Someone measured me once during a sporting event. Three second lens changes, on average. And those lenses were in my bag. (Lens off the camera, in the bag, cap off the new one, onto the camera; and yes, you have to have a ritual for this if you want to do it fast. Not that I'm advocating that you do it fast, as that leads to occasional problems of its own. It's only that most people overestimate how much time and effort really goes into switching lenses.)
- Better DOF. The claim here was that you could isolate subjects better with the 18-200mm on a DSLR than a bridge camera. Yes. And you can get more DOF with the bridge camera. There's no clear winner here, though I'd point out if you think your photographic style is even occasionally about isolating subjects off backgrounds, a lens that's f/5.6 with so-so bokeh is not the choice you should be making. At the least, carry one of the fast 50mm lenses with you for that, but that brings us back to carrying multiple lenses again, so the all-in-one approach is right out the window from the start.
Make a considered, reasoned, rational decision about what you take with you on vacation. If you're trying to convert your expensive equipment into a compact camera, you might be better off with a real compact camera is all I'm saying.
One thing I noticed, both with myself and with other serious photographers is this: when the 18-200mm first came out, it was a good choice and it stayed on my DX bodies a good part of the time. Then we started seeing lenses like the 16-85mm and some small, AF-S primes show up. They're optically better than the 18-200mm, and give us some additional options (wider, faster, etc.), so the 18-200mm went into the closet. And it hasn't come out for me. That's because it is indeed a "compromise lens." Yes, it's a good lens, nothing has changed about that, though we've got some optically better choices now (I'd personally pick the 18-105mm VR over the 18-200mm VR for a big range all-in-one lens, then add something really telephoto for those times when I really needed more than 105mm). The 18-200mm is a "compromise lens." So make sure that you know what the compromise is and that you're 100% comfortable with that before you opt for it.