Let's break it down:
Arguments *For* a 70-200mm for Portraits:
* Compression: This is the biggest reason. The longer focal lengths (especially above 135mm) create beautiful compression, minimizing distortion and giving a flattering look to facial features. Backgrounds also appear closer and more blurred.
* Background Blur (Bokeh): The longer focal length combined with a wide aperture (typically f/2.8 or f/4) allows for fantastic background blur, isolating the subject and creating a creamy, dreamy look.
* Subject Distance: It allows you to work from a comfortable distance, which can be less intimidating for the subject, especially for shy or non-professional models. You can capture more candid and natural expressions.
* Versatility: The zoom range offers flexibility. You can go from a medium shot (e.g., waist-up at 70mm) to a tight headshot (e.g., 200mm) without physically moving.
* Reach: Ideal for outdoor portraits where you may not be able to get close to your subject due to space limitations or environmental constraints (e.g., shooting in a crowded park).
* Professional Look: It's a staple lens for many professional portrait photographers and can add a certain level of perceived seriousness to your gear.
* Sports and Wildlife Versatility: If you shoot portraits AND other genres like sports or wildlife, the 70-200mm becomes an even more compelling purchase.
Arguments *Against* a 70-200mm for Portraits:
* Cost: 70-200mm lenses, especially those with wide apertures (f/2.8), are often quite expensive.
* Size and Weight: They are large and heavy lenses, which can be tiring to carry around for extended shoots. This can impact portability and comfort, especially when shooting on location.
* Not Ideal for Tight Spaces: In small studios or indoor environments, the long focal length can be restrictive, forcing you to stand too far away from your subject.
* Alternatives Exist: There are many other excellent portrait lenses, such as 35mm, 50mm, 85mm, and 135mm primes, which can offer equally stunning results, sometimes with even wider apertures.
* Learning Curve: Managing the shallow depth of field at longer focal lengths and wide apertures can take practice and precision.
* Overuse of Bokeh: It's easy to become overly reliant on background blur, which can sometimes detract from the overall image if not used carefully. Sometimes you *want* context in the background.
* Lack of Connection: Some photographers feel that the distance created by a 70-200mm lens can hinder the connection with their subject, making it harder to establish rapport.
Who *Needs* a 70-200mm for Portraits?
* Outdoor portrait photographers: Who frequently shoot on location and need reach and background blur.
* Photographers who want maximum compression and flattering portraits.
* Professionals who require versatility and a "go-to" lens for a wide range of portrait situations.
* Photographers who also shoot sports, wildlife, or other genres that benefit from a telephoto zoom.
Who *Might Not* Need a 70-200mm for Portraits?
* Studio portrait photographers: Who primarily shoot in controlled environments and can easily move closer to their subject.
* Photographers on a tight budget: There are many more affordable portrait lens options.
* Photographers who prefer a more intimate, connected style of portraiture.
* Photographers who value portability and lightweight gear.
* Photographers who prioritize wider angle shots for environmental portraits.
Alternatives to the 70-200mm:
* 85mm Prime Lens: An excellent and often more affordable option for portraits. Offers beautiful bokeh and compression, while being smaller and lighter.
* 135mm Prime Lens: Provides even more compression than the 85mm, but requires more working distance.
* 50mm Prime Lens: Versatile and affordable, great for environmental portraits and can still produce nice bokeh with a wide aperture.
* 35mm Prime Lens: Ideal for environmental portraits and capturing more of the scene.
Conclusion:
While a 70-200mm lens is a fantastic tool for portrait photography and a staple for many professionals, it's not a *mandatory* requirement. The best lens for you depends on your specific needs, shooting style, budget, and the type of portraits you want to create. Consider the pros and cons, experiment with different focal lengths, and choose the lens that best suits your individual artistic vision. Don't let the perceived "need" for a 70-200mm hold you back from creating beautiful portraits with other excellent lens options.