I am looking for a budget telephoto lens. The Canon 55-250 and Tamron 18-200 are both within my budget. I am slightly inclined towards getting the 18-200 because of the range it has. I looked up for reviews for this and couldn't find any good review with pictures from this lens. Can any one respond with quality of pics at 200mm ? Is it a good buy even though it doesn't have IS like the Canon 55-250?
If you don't really need to be able to shoot wide with the same lens, then you'll generally get much better quality from a lens with narrower zoom range. To get a ~10x zoom range like the 18-200 compromises have to be made.
The Canon lens has a smaller zoom range, yet more reach and has stabilisation so is a better option on paper, however I've never used it so don't know how it performs in the real world.
Both lenses are designed for APS-C sensors only, if are thinking of upgrading to full frame you might want to consider a full frame lens, as in the telephoto range there is little weight penalty for the larger image circle.