Your DSLR can take outstanding photos on its own in auto mode, so why would you want to switch to manual? This video tutorial will explain the reasons why as a photographer you might want full manual...
Here's a photo from Costa Rica. That's Diane
Ewing, consummate horsewoman and proprietress of Hacienda Barú.
Her face would be completely black if a pop from the built-in flash of
the Canon EOS-5 (film) body had not filled in the shadow under her
hat. Canon 20-35/2.8L zoom lens. Fuji Sensia film. Photographer
also sitting on horse (tripod is generally preferable to quadruped).
Note that with environmental portaits, you don't necessarily use a
"portrait-length" lens. In fact, often a wide angle lens of some kind
is used, typically closer to 35mm than 20mm (full-frame/35mm film).
Here are some more examples of photos that might reasonably be called
If the photo captures something that you remember about a person, there is
no need to show the whole face clearly. The photo may have a lot
of meaning to friends and family even if it doesn't communicate much
to a stranger.
Do you really need the wide aperture?
The photo at left (Dieter) was
taken with a Canon 35-350L zoom lens. The 35-350L slows down to
around f/5.6 at longer focal lengths. The photo at right (Emma) was
taken in Alaska's Katmai National
Park in front of a background with similar potential for distraction.
Emma was captured on film with a
300/2.8 lens. You can decide for yourself whether the reduction in background
distraction is worth the cost and weight of a fast lens.
This was taken on vacation with a Canon S60 point and shoot digital
camera. The small sensors of point and shoot cameras necessitate very
short lenses. Even at wider apertures, these lenses have way too much
depth of field for portraits and the background will always be distracting.