The right wide-angle zoom

fansmanship wrote:

photonius wrote:

fansmanship wrote:

Hey everyone. First time posting on the forum, so bear with me.

I shoot sports and action a lot - basketball, etc...

I have two Canon bodies (70D and T3i) and am looking at a better wide angle lens. Here are the lenses I have:

18-55 kit lens

70-200 2.8

50mm 1.8

85mm 1.8

I'm thinking to sell the 85mm 1.8 and buying a better wide-angle (2.8) lens where the AF is going to work fast enough for sports like basketball.

As I see it, I have 2 or 3 options if I'm not going with a Canon 24-70 (since I don't have over $2000 to spend).

1) 18-55 f 2.8. It's not an L series lens but seems like the AF would be quick enough? and price is $850-$900 range... which is doable.

presumably you mean the Canon 17-55 f2.8 IS (there is a sigma 18-50 f2.8 lens).

It's top notch, your best bet.

Yes. this is what I mean. Obviously it wouldn't work with FF body. Does that also mean that the 17-55 will give me 17-55 with cropped sensor (since it's made for those cameras) or would it still by 1.6x?

The lens has a focal length.

Whenever we use the smaller APS-C size sensor, we must multiply by a crop zoom factor of 1.6; this gives us the focal length in full frame equivalent.

When we use a full frame sensor, we don't have to multiply by anything at all.

2) Tamron 24-70 VC 2.8. I know it's Tamron's run at Canon's 24-70, but what does the AF look like on this one? I've never bought a Tamron lens and I'm sure it looks fine comparatively for my taste, but I'm definitely concerned about the function of the AF in comparison to a canon...

That's a standard lens for FF. it's not very wide at all on crop, why don't you try your 18-55 at 24mm to see how much you loose at the wide end. But maybe it's the focal length you want?

Yes. I'm pretty confident in the Tamron the more I read about it, but your point is well-made about the zoom. I suppose I could test it using my kit lens (depending on your answer to my question above). What do people know about the AF capabilities of the Tamron? Should I be worried?

Have a look at this YouTube 4-way comparison between the EF-S 17-55 f2.8 3x zoom, Sigma 17-35 f1.8 2x zoom, Sigma 17-50 3x zoom f2.8 and the Tamron 17-50 3x zoom f2.8.

Note that all these lenses have wide apertures of f/2.8, but their zoom ranges have been greatly diminished down to just 3x zoom, where a typical EF-S 15-85 has a small f/3.5-5.6 aperture, but has some 6x zoom range.

Note too how the Sigma 17-35 f/1.8 only has 2x zoom range, but has an even bigger aperture of f/1.8.

Thus, the wider the aperture, the shorter or shallower the zoom range.

A prime lens has really big apertures like f/1.4 or even f/1.2, but it has only the single focal length.

Life is a compromise...