Which 50mm should you buy?
"A 50mm f/1.8 lens tends to cost in the $100-150 range—the same as a kit lens—while an f/1.4 lens costs at least twice as much. At their widest apertures, these lenses produce a very narrow depth of focus and create separation between subject and background (or foreground) that adds dimensionality to your photos for flattering portraits.
There’s so little difference, spec-wise, between an f/1.4 and an f/1.8, but the difference in price is huge. How does that translate as far as image quality? All settings being equal, does one lens outperform the other?"
(For those who don’t want to geek out, let me give you the summary and spoil the ending: For both Nikon and Canon 50mm lenses, overall image quality is generally sharper, with less vignetting and fewer aberrations over the range of apertures with the less expensive f/1.8 version. In most (but not all) cases, this makes the f/1.8 a more desirable lens. Why? Read on!)
Photo credits: Alvera.