Traditionally, portraits are shot with focal lengths between 50mm and 135mm, though there is no reason you can't use a longer focal length. Nonetheless, 400mm f/2.8 lenses are traditionally reserved for professional sports and wildlife photographers who need a lot of reach and the ability to capture as much light as possible. With super-sharp results and a narrow depth of field, they seem like a great (if somewhat impractical) option for portraits, and this fun video shows you what you can expect.
Coming to you from Julia Trotti, this fun video shows you the results of shooting portraits with a Sony a7R IV and FE 400mm f/2.8 GM OSS lens. At $12,000, no one is buying such a lens just for portraits, as they are really made for sports and wildlife work. However, if you have one, it is quite neat to see what you can create, as the very long focal length and extremely narrow depth of field can make your subject really pop out against the background. I frequently use one for recital photography, and it is a great way to make a soloist really pop off the stage. Check out the video above to see Trotti's work with the lens.
Although you "can" spend the $12,000 for a new 400mm 2.8 they are available used in good condition for around $1,000 if you are truly seeking one out. I've had two and one Canon FD manual one, so 3. Nothing can beat their bokeh and compression. Thankfully mirrorless with its eye detection really makes these oldie goldies shine. Also the new ef rf drop in filter converters allow polarizers, nd, etc. Of course the one she is holding weighs less than my 13lb original Canon one, but using a monopod can be fun.
Lens looks crazy sharp 😮
I knew someone who did portrait photography with a 600mm lens.