<p>Good information from the previous posts. If traveling to Europe you should consider the Canon 10-18mm, it would match up nicely with what you already have. If you are happy with the quality of the 18-55 and 55-250, then I would just stick with them, and add the 10-18. That way you have a whole range (10mm-250mm) covered by 3 lenses. This wide angle option might come in handy for European Architecture and landscape type photography...perhaps a "selfie" here or there :)</p>
<p>One point... for most bus tours, you are not going to want to waste time fiddling with lenses...you might not have time. They usually stop at a location, for a set amount of time, then you are off again. This is when the convenience of a zoom lens comes in handy. This is also true even if you were not on a bus tour... </p>
<p>I took a 50mm f/1.8 on a 3wk backpacking trip to Europe....I used it twice...(but I had my Tamron 17-50 f/2.8) Your style might be different than mine, but I probably wouldn't take the 50mm f/1.8 again. </p>
