Received my Tamron 17-70mm today...

BeatX wrote:

Lettermanian wrote:

BeatX wrote:

Thx for sharing Your opinion

Uhh.. That Tamron 17-70/2.8 is big! I mean it looks like similar size to any 24-105/4 FF zoom lenses (?) for me personally standard zoom lens of this size for APSC camera is wired idea. Beside VC (and Fuji color science), there is very little adventages of such huge lens attached to Fuji camera, where You Can get for example R6 + 24-105/4 IS L lens in similar size compared to X-T4 + T17/70/2.8. And You got all adventages of FF sensor, plus better AF.

In my opinion, new Sigma 18-55/2.8 is essense of standard zoom for APSC camera (or Tamron 18-300 for hiking)

A 2.8 lens is still a 2.8 lens in terms of light gathering, so there's not a direct comparison to a 24-105 f4. A 2.8 24-105 on ff would be huge and heavy. I've recently owned Nikon's Z5 and 6ii w/24-200, a Panasonic S5 with a 24-105 f4, and they're all very nice and full-framey, but as a system Fuji still has advantages for my purposes: better ooc colours and reach in a lighter-weight package than ff. There's no ff lens in any current system that gives 450mm-equiv non-cropped images at the size and weight of Fuji's 70-300. While the 17-70 is big, it's lighter and slimmer than Fuji's own 16-55mm f2.8, so for Fuji users it can be advantageous, if the IQ is close.

Yes, I know that f/2.8 lens is still an f/2.8 lens, but my point is that comparing two lenses like: Tamron 17-70/2.8 vs Canon 24-105/4 IS L (closest competition) will give exact same results when they are used on APSC body vs FF body.

DOF from APSC f/2.8 is same as FF f/4 lens, angle of view from 17-70 is same as 25-105 in FF. The fact that f/2.8 lens gathers exact 1EV more light than f/4 (so You can go down with ISO) can be compensate without a problem, by pushing up ISO in FF camera by 1EV, where in FF camera You have way less noise in high ISO

Only thing what comes to my mind that Tamron 17-70/2.8 + APSC body is better option than 24-105 lens + FF body is small weight difference plus lower price, and that's it

Anyway I'm happy for You, and rally wish You to get some great shots with this new Tamron!

So a day after I posted my reply to your comments I should clarify that in terms of equivalence, you are correct when describing the effect of aperture and sensor size relative to other systems.  In all honesty though that wasn't what I was referring to when I wrote my reply, but as a busy working family man with kids at home for the summer, etc, I wrote in haste and did a poor job of explaining what I was thinking. So as my comments stand, you are correct indeed. If I could write my first sentence again though, I would say "A 2.8 lens is still a 2.8 lens in terms of light gathering and within its own format/system...".

I wasn't really meaning to talk about equivalence, even though that is what you were addressing. I was meaning to respond to your observation about the size of the lens compared to a ff lens, and that you thought it was a "weird" idea. I was thinking in terms of 2.8 lenses within their own sensor formats to counter-argue your criticism about its size. Basically I meant to say that this 2.8 APS-C lens wasn't a direct comparison to an f4 FF lens when they are considered in their own respective systems, because the Tamron is cheaper, smaller and lighter than a (theoretical) full-frame 24-105mm 2.8 would be in a FF system.

If we compare pricing of the combos you mentioned, where I live the R6 +24-105 f4L combo is still $1500 more than the Fuji X-T4 + 17-70 combo. Further, if we compare prices on 2.8 lenses within different systems, an APS-C system is generally going to offer smaller, cheaper, lighter lenses, that essentially fill the same role and function as 2.8 lenses in full-frame (or any other system). Equivalence aside:-)

Hopefully that's a clearer explanation of what I was meaning to say. I'm hoping I can actually get out shooting with it soon instead of talking about it!