Generally speaking, on the 70-200 focal length, I prefer the f/2.8 despite the significant size/weight difference -- ironically not for the f/2.8, as I'll often stop down to f/4 anyways... but for the better/faster autofocus that a wider aperture affords.
There are many situations indoors when it's not as bright, and f/2.8 focuses noticeably more confidently than f/4, and for patio birding, if it's a bit overcast, f/2.8 makes a huge difference.
bsbeamer said:
My biggest issue with Tamron lenses is lack of in-camera lens corrections, or non-functional lens corrections, specifically peripheral illumination correction. The vignetting can be a problem with these lenses and is generally harder to fix with video (than shooting RAW and fixing in Lightroom/Photoshop).
I've always wondered about this, but I barely ever record videos, so I've never taken the time to research it.
The only video I've ever made on my 80D was of a heron "fishing" using a Sigma 150-600, the vignetting was, well, pretty much what you'd expect from an uncorrected telephoto (looks silly). Is there any way to correct this "automatically" in post?
bsbeamer said:
If Canon ever released a 24-70 F2.8 with IS, I would likely change everything over.
IIRC, the rumor is Canon is field testing two models of 24-70/2.8 IS
I would purchase that lens in a heartbeat too.