A 70-200mm telephoto zoom lens is an extremely versatile tool. So veratile, in fact, it's often a pro photographer's most-used lens (or maybe just behind their general purpose zoom). Engagements, weddings, parties, events, theater, stage performances, high school senior, fashion, documentary, lifestyle, zoo, product and landscape photography are all great uses for this focal length range.
If you're looking to add a 70-200(ish) mm zoom lens to your kit, and don't need an f/2.8 max aperture and/or don't want the size/weight/cost penalties tied to the wider aperture, then the Canon EF 70-200mm f/4L IS II USM and Tamron 70-210mm f/4 Di VC USD Lens are likely at the top of your considerations list. Both lenses feature an f/4 max aperture that can be stopped down to f/32, nine rounded aperture blades and built-in stabilization. Where the two lenses differ, of course, will determine which one is the better candidate for your kit.
Canon EF 70-200mm f/4L IS II USM and Tamron 70-210mm f/4 Di VC USD Shared Features
Primary Advantages of the Canon EF 70-200mm f/4L IS II USM Lens
Primary Advantages of the Tamron 70-210mm f/4 Di VC USD Lens
Other things to consider:
Who should opt for the Canon EF 70-200mm f/4L IS II USM Lens?
From an image quality perspective, most photographers will appreciate the sharpness of the Canon EF 70-200mm f/4L IS II USM's images compared to the better distortion and vignetting performance of the Tamron. If you're shooting in situations where you can't afford to miss focus, the Canon's better autofocus performance (both in accuracy and consistency) will more than offset the lens' higher acquisition cost, especially in low light situations. And in regards to low light situations, the Canon's 1-stop higher rated stabilization system will help you get sharper images of non-moving subjects under the same shooting conditions. For those that will typically utilize the lens at its longest focal length, the Canon's better image quality at 200mm will certainly be appreciated. If intending on having your 70-200mm lens mounted for long periods of time, the Canon's rearward positioned zoom ring will certainly be more comfortable to use. And finally, if you currently only have Canon-made zoom lenses in your kit, acclimating to Tamron's reversed rotating zoom and focus rings can be maddening, especially when a fleeting shot opportunity requires a fast reaction speed.
Who should opt for the Tamron 70-210mm f/4 Di VC USD Lens?
If your budget does not extend to the Canon equivalent, the Tamron 70-210mm f/4 Di VC USD Lens offers many of the same benefits at at less than two-thirds the cost (without rebates). For those who plan on using their medium telephoto zoom primarily for static portraiture, especially when a focus-and-recompose technique can be employed while using the enter AF point, the Tamron's AF performance should be more than sufficient for the task. Do you own an EOS Rebel-series camera body without the ability to fine-tune AF parameters via Autofocus Microadjustment? The Tamron may prove to be the safest choice as you can compensate for autofocus miscalibration issues via the optional TAP-in Console; if you experienced a similar issue with the Canon lens, you'd need to send your camera and lens to Canon's Service Department for calibration, a much less convenient solution to the problem.
Note about focal length range difference: The extra 10mm of focal length range provided by the Tamron will not be terribly significant from a practical standpoint. For instance, the difference in framing the an identical target at 200mm with the Canon and 210mm with the Tamron amounted to slightly more than 1' (305mm), meaning you could get the same basic framing with the Canon lens by leaning forward.
Summary
As you can see, from a specifications standpoint, these lenses are very similar. If your budget extends to the Canon EF 70-200mm f/4L IS II USM, and you'll be using it with a body that features Autofocus Microadjustment, we highly recommend adding the L-series lens to your kit because of its sharpness, IS/AF and balance advantages over the Tamron. However, if your budget is more limited, the Tamron 70-210mm f/4 Di VC USD is an excellent value when its versatility and overall performance are considered.
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