Wow, this might be a great air show lens...

Tamron 150-600 zoom lens for FF and APS-C cameras. Looking forward to the reviews...

http://www.dpreview.co​m …medium=text&ref​=title_0_1

Hmmm...seems like no interest here.

In development,pricing and availability to be announced. Guess it's a bit early to even consider.

f/5-f/6.3 is what I would consider a fairly slow lens...

I dunno, in daylight I bet you could shoot full speed, maybe bump the iso. I think it sounds great, I would be curious to see spherical and chromatic abberation handling at the long end.

FlyingPhotog wrote in post #16446274
f/5-f/6.3 is what I would consider a fairly slow lens...

I could see 6.3 at 600mm.... but F5 at 150mm? Too slow lol.

FlyingPhotog wrote in post #16446274
f/5-f/6.3 is what I would consider a fairly slow lens...

In what context; IOW, compared to what other options?

50mm f/1.2 is considered a fast lens, but put a 12x TC on it, and what do you get? You get a 600mm f/14.4, with little subject isolation.

Do that or crop at 8.33% of the full image, and you get as much final image light as if you had used 144x the ISO.

If you don't understand your equivalencies, you are bound to make assessments that sometimes have no practical value. Depth isolation and subject-level noise are dependent most directly on things like physical aperture size; not derivative abstractions like f-stops.