Canon EF-S 15-70 f4 IS - too much too ask?

[Corylus]

If this lens was made available with similar build quality to the EF-S 15-85 I would jump on it right away and I suspect a great many other APS-C users would too.

I will be upgrading my 40D in the near future and don't need FF so will be getting the 7D or it's newer incarnation if available by that time (wishful thinking probably). I would really like to see a 15-70 (or there abouts) constant f4 lens developed as a kit lens for a high end APS-C package in the future. Is there any technical reason why this lens could not be achieved? I certainly think there is a place for a 24-105 equivalent for APS-C bodies - it would be a nice compromise between the current 17-55 f2.8 and 15-85 f3.5-5.6.

Anyone else fancy this lens?!!

[EYEONE]

There was a rumor a while back about a EF-S 15-60mm f2.8. It seems like that would fit what you mentioned. F4 and 10 more mm would probably work fine.

[Corylus]

There was a rumor a while back about a EF-S 15-60mm f2.8. It seems like that would fit what you mentioned. F4 and 10 more mm would probably work fine.

That'd be nice too but I'd rather not pay a premium for f2.8 - I have a fast prime for low light/indoor shots. f4 would be perfect for my needs (smaller, lighter, cheaper) but sadly I don't pull the strings at Canon

[unfocused]

I'd take either one. A constant f4 in a 15-70 (or longer) lens would be ideal in my mind. 15-60 f2.8 would be okay, but I'd trade one stop for a longer focal length in necessary.

[EYEONE]

I'll take the 2.8 over the few steps forward I could take in focal length.

[gmrza]

I'd take either one. A constant f4 in a 15-70 (or longer) lens would be ideal in my mind. 15-60 f2.8 would be okay, but I'd trade one stop for a longer focal length in necessary.

I use the 17-40 f/4L a lot on a 7D.  Only having f/4 has a number of shortcomings - firstly because the depth of field is roughly equivalent to f/5.6 on full frame, and secondly because with the 7D you literally have 1 stop less latitude than on the 5DmkII in terms of high ISO noise.  Then, for a general purpose walkabout lens, there is the lack of IS.  The EF-S 17-55mm f/2.8 IS probably comes closest in terms of lenses that currently exist, although it is still not quite "equivalent" of the 24-105mm f/4L on full frame, because you lose out on the short and the long end.

For crop frame, I guess my ultimate walkabout lens would be a 15-70mm f/2.8 with IS, but I think that would only exist in my dreams.  I would probably be better shutting the &%&( up and waiting for the 5DIII....

[briansquibb]

... and then an F/2.8 is desirable because it improves AF with the more sensitive AF ponts .....

[mb66energy]

[...]
Anyone else fancy this lens?!!

YES! As you can see from my focal length listing it would be the lens to fill the gap with a walk around zoom. And the combo 15-70 and 70-200 @ f/4 + with IS would be a extremely versatile one.

You say f/4 and that is IMHO the right way: It should be possible to design a zoom with f/4 and a focal range of 15-70mm with great image quality at a moderate price tag of ca. 800 $ / EUR ... at f/2.8 it would be 2000 $ / EUR for the same image quality and the lens would be to large and heavy as a walk around lens to be with you (nearly) all the time.

Best - Michael

[lol]

For comparison, I did move to Canon from Sony, and their Zeiss 16-80 f/3.5-4.5 was nice. It's not constant aperture either, but that bit more aperture on the long end did help at times.

So, why fixed aperture? Why not even faster variable on the wide end like the Sigma 17-70mm f/2.8-4?