Is the ttartisan af 40mm f 2 good in low light?

Yes, it's a reasonable choice for low light, with a few caveats. The 40mm f/2 is a fast prime, so it gathers more light than a typical kit zoom, which matters most in dim rooms and at night. Primes and zooms explains why that speed helps. It has no stabilisation, so you'll want a steady hand or a camera with stabilisation of its own.

On full frame it's a true 40mm, and full frame gives you about a stop more low-light headroom than APS-C, as what a bigger sensor buys you explains. If night work is your main use, pair it with a full-frame body. The Sony a7S III is on this lens's compatible list and is a sensible place to start.

Written by Claude from this site's pages.