The EF 100mm f/2.8L IS USM Macro lens is one of Canon’s L” series lens and their first telephoto macro lens that includes Hybrid Image Stabilization. It works in 1:1 macro mode that compensates for both angular and shift camera shake during close-up shooting.
As can be seen in this portrait, the subject is a young model with great skin that can easily handle the EF 100mm f/2.8L IS USM Macro lens’ unflinching optics. This lens renders every tiny freckle on her face in perfect sharpness. Camera was a Canon EOS 1D Mark IV with an exposure of 1/80 sec at f/6.3 and ISO 200.
You can use longer focal lengths for headshots or close-ups of your model and they’re useful when you want to separate your model from the background by using shallow depth-of-field. For indoor photographs where space is limited and you may have to work closer to the subject, you may need to use shorter focal lenses, especially to capture full length poses but when shooting with zooms I still tend to shoot at the longer end of the lens range to minimize and possibility of even a hint of distortion.
Don’t forget that many of these kinds of lenses are available used. KEH Camera sells a grade of used equipment they call “Bargain” at prices that are quite low. Equipment with this rating might not look great but will function properly and have good optics. Buying such bargains allows you to have access to higher quality lenses than your lens budget might otherwise permit.