70-200 vs 18-200

[Makhaira]

Noob question incoming!

I've taken the plunge and I'm learning about photography with a 100D I recently got from the MM here following a holiday in Iceland. Most questions I'm thinking of are generic ones and I can find claer answers, but not so this one (although I've found various articles giving me bits of the answers).

What's the practical difference between 70-200 and 18-200? From what I've managed to read, the 18-200 can struggle a bit in terms of image clarity due to the range it covers, and usually has a higher f-stop. Is that a fair summary of the differences, or is there more at play here?

Thanks.

 

[MichaelAwkward]

It depends on what 70-200 or 18-200 lenses you're considering.

For Canon, their 70-200 lenses (F4, F4 IS, F2.8, F2.8 IS) are much better optically and mechanically (in terms of ergonomics and AF speed) than any 18-200 available. They're also much more expensive, and much heavier.

It also depends on what you're shooting and what you want to achieve.

A 18-200 lens is a compromise on image quality for the sake of convenience, generally. They're all going to be a lot softer at the telephoto end compared to a 70-200. I think something like the 15-85 would be a better choice as a walk around lens for Canon in Iceland. By that I mean, you're more likely to want something wider than 18 than you are to want longer than 85 for the types of shots I imagine you'll want to take there.

Of course, it all ultimately comes down to how seriously you want to take your new hobby

General consensus is that the Tamron and Sigma equivalent (18-270 PZD and 18-250 HSM OS) perform better than the Canon 18-200, if you decide a superzoom is worth the convenience. The new Tamron 16-300 is getting good reviews too, but it's a fair bit more expensive.