You asked
Is a 150 600mm lens worth it?
Yes, if birds and distant wildlife are what you shoot. Reach is the hard part of that work, and 150-600mm gives you more of it than most zooms. At f/5-6.3 it is slow, so you'll want good light or a camera that handles high ISO well. All three of these are full frame lenses:
- The Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary is the lighter option, and the one I'd start with if you plan to carry it.
- The Sigma 150-600mm f/5-6.3 DG OS HSM Sports is heavier but weather-sealed, which matters if you shoot in rain.
- The Tamron SP 150-600mm f/5-6.3 Di VC USD is the first-generation version.
On APS-C, a 100-400mm gives a similar view in a lighter kit. See Wildlife and sport. Long lenses hold their value, so buying used saves a lot.
Written by Claude from this site's pages.