For full-frame cameras:
* Canon EF 50mm f/1.2L USM: A legendary lens known for its incredibly creamy bokeh (background blur) and exceptional sharpness, but it's expensive and quite large.
* Nikon AF-S NIKKOR 50mm f/1.4G: Another excellent choice offering beautiful bokeh and fast autofocus, representing a strong value compared to the Canon equivalent.
* Sony FE 50mm f/1.2 GM: Sony's top-of-the-line 50mm, offering incredible image quality and speed, but at a premium price.
* Sigma 50mm f/1.4 DG HSM Art: A third-party option that often competes with the top performers from Canon and Nikon in terms of image quality and features, at a generally lower price point.
For APS-C cameras:
The best lens for an APS-C camera will effectively be a shorter focal length (around 35mm equivalent). However, many 50mm lenses designed for full-frame cameras will work on APS-C cameras, offering a longer effective focal length, which can be beneficial for portraits. Look for recommendations specific to your APS-C camera system (Canon, Nikon, Sony, Fuji, etc.) as the optimal choices will vary by mount.
Factors to Consider When Choosing:
* Aperture: A wider maximum aperture (e.g., f/1.4, f/1.2) allows for shallower depth of field, resulting in that desirable blurry background. However, wider apertures also generally mean higher price and potentially less sharpness at wider apertures.
* Autofocus: Fast and accurate autofocus is crucial for capturing sharp portraits, especially when shooting moving subjects.
* Image Stabilization: While not essential, image stabilization can be helpful in low-light conditions or when shooting handheld.
* Build Quality: A well-built lens will be more durable and withstand the rigors of regular use.
* Price: Lens prices can vary significantly, so consider your budget carefully.
* Bokeh: The quality of the background blur is subjective, but generally, a wider aperture contributes to smoother, more pleasing bokeh.
Recommendation:
Before making a purchase, I strongly advise you to read reviews from reputable sources like DPReview, Ken Rockwell, and others specific to your camera system. Look at sample images to see how the lens renders bokeh and sharpness to your liking. Many professional photographers have YouTube channels dedicated to lens reviews. That research will help you determine the best 50mm lens for *your* needs and preferences.