The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 18-200mm f3.5-5.6 IS and the Canon 17-85mm f4-5.6 IS USM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Canon 18-200mm f3.5-5.6 IS is the longer of the two lenses at 102mm. The Canon 17-85mm f4-5.6 IS USM with a length of 92mm, is 10mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 79mm.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Canon 17-85mm f4-5.6 IS USM weighs 475g, 20% (120g) lighter than the Canon 18-200mm f3.5-5.6 IS's weight of 595g.
Filter Threads
The Canon 18-200mm f3.5-5.6 IS has a filter size of 72mm whereas the Canon 17-85mm f4-5.6 IS USM has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Canon 18-200mm f3.5-5.6 IS:
And these are the 67mm filters that we recommend for the Canon 17-85mm f4-5.6 IS USM:
Lens Mounts
Both the Canon 18-200mm f3.5-5.6 IS and the Canon 17-85mm f4-5.6 IS USM has the same Canon EF-S lens mount. Some of the latest released cameras that are compatible with the Canon EF-S lenses are Canon T8i, Canon 90D and Canon SL3.
Focal Range
Canon 18-200mm f3.5-5.6 IS has a focal range of 18-200mm and
11.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
28.8-320mm when used on a APS-C / DX format camera.
On the other hand, the Canon 17-85mm f4-5.6 IS USM has a focal range of 17-85mm and 5.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27.2-136mm when used on a APS-C / DX format camera.
