You asked

Canon ef 35mm f 1 4l usm vs tamron sp 35mm f 1 8 di vc usd?

The Canon EF 35mm f/1.4L USM is the low-light and shallow-focus pick. It's a stop faster than the Tamron, and on Canon APS-C bodies it gives about the depth of field of f/2.2. The trade-offs are that it isn't stabilised and it only comes in Canon EF mount.

The Tamron SP 35mm f/1.8 Di VC USD is the more practical everyday lens. It's stabilised, which helps in dim rooms when you don't have a tripod, and it's made for Nikon F as well as Canon EF. You give up a stop of light for that flexibility.

If you shoot Canon and mostly work in very low light, I'd go with the Canon. For most other uses, the Tamron is the better buy. For people shots in particular, see portraits.

Written by Claude from this site's pages.

From these pages