Is 'L' glass and a 1.4x converter better ?

[sweepiedog]

Can anyone tell me if a 28-70L and a 1.4 Converter will give better quality shots than a standard 35-100. Will the 1.4x converter degrade the image enough to make the 'L' lens not worthwhile ?

[EXA1a]

Can anyone tell me if a 28-70L and a 1.4 Converter will give better quality shots than a standard 35-100. Will the 1.4x converter degrade the image enough to make the 'L' lens not worthwhile ?
Teleconverters generally don't work well on wide angle lenses.
The Canon teleconverters won't work on a 28-70mm lens.
Some cheap third-party converters might work mechanically but their optics are bad.
For sure the 28-135 Canon lens will produce better results.

--Jens--

[Belmondo]

You can't use the Canon 1.4X TC with the 28-70L, so I'm not sure what the quality would be. My only experience is with the 1.4X Canon TC on Canon L telephotos. In that case, the quality is certainly equal to or better than most non-L lenses of the same equivalent focal length.

I have no experience with the 28-70L, although I do own the 24-70L lens, and it is arguably the sharpest lens I own. How it would behave with a non-Canon extender is purely a matter of speculation, but I would think it should be okay.

[CyberDyneSystems]

Physically you may be able to fit a "kenko" 1.4X or another non canon T-con.. but the image would vignette dramatically at the wide endd of things.. it may even Vignette at 70mm