kevin519 wrote:
So I was thinkin this mornin, most will agree for portraits an 85mm is best, some will say other lens', but for the most part an 85, but what about the crop vs FF body? So what if you use a 50mm, with a crop of 1.6 that puts you at 80mm right, and the 85 at 136, so now what? So is it the mm, or the f/???, or is it in the way the 85mm is built, I just dont know. I have a fast 50L lens, and a 2.8 70-200 which can hit that 135mm spot easy, so why would I buy a 85mm?
On full frame, the traditional "short portrait" and "long portrait" lenses are 85mm and 135mm. Some like wider 50mm or even 35mm for "environmental portraits" that show some of the person's workplace or surroundings. Some like a longer 200mm for "fashion portraits", if they have a lot of work room. And some choose a 90mm or 100mm or 105mm, perhaps a macro that can serve dual purpose as a portrait lens.
On crop cameras, 50mm and 85mm serve as the short and long portrait lenses. 35mm, 30mm, 28mm and 24mm are environmental portrait lenses. 135mm works well for fashion photography. And a 50mm or 60mm macro lens might be used.
In other words, whatever constitutes a short telephoto on any given format is a traditional portrait lens and will give the most ideal perspective effects for the purpose. Standard to moderately wide lenses have to be used carefully for portraiture. Not too close, or they'll exaggerate size relationships... big noses and tiny ears. You also have to be careful not to position a subject too close to the edge, when using a moderately wide lens, due to inherent distortions. Conversely, a longer telephoto tends to compress perspective. That's a more subtle effect that can be useful for certain types of portraits, provided you have plenty of work space.