Which telephoto lens to invest in?

[Mjump54]

I shoot lots of wildlife, landscape and equestrian pictures. I have a Tamron 150-600mm lens but want to invest in good Canon zoom. In your opinion, which would be better - the L series 70-200mm or the 100-400mm? I would also likely pick up the 1.4 extender. Thx.

[ebiggs1]

Asked and answered!    The Canon EF 100-400mm f/4.5-5.6L IS II USM Lens can use the 1.4x tel-con.

[Uzmas]

70-200 in my opinion. Really depends on the distance. The fav in my kit is the 70-200 for our purpose which is wedding photography. For wildlife, if I wete doing it...i would stick with Canon.

[TCampbell]

Which camera body?

The 70-200 and 100-400 are completely different beasts.  The 100-400 is pretty much just for telephoto photography (action/sports/etc.).  It's fantastically sharp and pairs well with the Canon 1.4x tele.  But there is a deliberately focus-speed reduction when you use the lens with the tele-extender (it will not focus as fast as it will without the tele installed ... and that's something Canon documents.)

The 70-200 is probably my most used lens.  I use it for a lot of things where people might use a shorter lens (when I have a choice between photographing something at shorter focal length and standing closer to the subject, or longer focal length standing farther from the subject... I pick the longer focal length and farther distance.  It love the look, the angle of view, the shallow depth of field I can get at f/2.8 (or even f/4) and the blur quality of the 70-200 that the 100-400 doesn't have.  

But If I'm shooting a sporting event... I'm probably using the 100-400m so I can more easily "fill the frame" in ways I probably can't do at 200mm.

This is why I say they're completely different beasts.  The 70-200 does some things you just can't achieve with the 100-400... and the 100-400 does some things you can't achieve with the 70-200.

That said... you already have a Tamron 150-600.  I'm not sure which version you have (Tamron has made several 150-600s).  The Tamron is covering most of the same range as the Canon 100-400, but the Canon has a reputation for being extremely sharp.