06-01-2011, 11:43 AM
[quote name='PuxaVida' timestamp='1306925054' post='8978']
A bigger image circle compared to the one on cropped sensor, has it's price I think. Why when some UWA zooms are huge and bulb-like when some others are rather small? The glasses used should better be larger for FF (retro focus design and light transmission), and these larger glasses must be produced with higher precision to avoid problems concerning spherical aberrations. Thus the higher quality and price for FF compatible UWA lenses. That said, I agree that there are affordable lenses (like the one you've mentioned) but FF is something that people usually choose for portrait or wide angle. And I personally don't think that the strong point of FF should be wasted by using a low grade lens.
Vignetting (not the mechanical one) is in general sensor related: edges must get more amount of photons in a perpendicular angle. The latter is what you've mentioned, but the amount of light depends on the design of the lens.
[/quote]
There is no difference regarding retro focus design... It is not like the APS-C lenses can sit closer to the sensor.
The APS-C ones need to bend light a lot more too to get the same field of view, CA being a bigger problem sooner.
There is nothing being "wasted" by making a good photo with an affordable lens on a full frame body. It is all about the photo, not the price of the gear.
Of course, one can also make great photos with an EF 24mm f1.4 L USM II, or a 16-35mm f2.8 L USM II. But at f8 one will be hard pressed to tell those apart from for instance that Tokina.
And the FF-Tokina combination will beat an APS-C + Tokina 11-16mm f2.8 too, at f8...
A bigger image circle compared to the one on cropped sensor, has it's price I think. Why when some UWA zooms are huge and bulb-like when some others are rather small? The glasses used should better be larger for FF (retro focus design and light transmission), and these larger glasses must be produced with higher precision to avoid problems concerning spherical aberrations. Thus the higher quality and price for FF compatible UWA lenses. That said, I agree that there are affordable lenses (like the one you've mentioned) but FF is something that people usually choose for portrait or wide angle. And I personally don't think that the strong point of FF should be wasted by using a low grade lens.
Vignetting (not the mechanical one) is in general sensor related: edges must get more amount of photons in a perpendicular angle. The latter is what you've mentioned, but the amount of light depends on the design of the lens.
[/quote]
There is no difference regarding retro focus design... It is not like the APS-C lenses can sit closer to the sensor.
The APS-C ones need to bend light a lot more too to get the same field of view, CA being a bigger problem sooner.
There is nothing being "wasted" by making a good photo with an affordable lens on a full frame body. It is all about the photo, not the price of the gear.
Of course, one can also make great photos with an EF 24mm f1.4 L USM II, or a 16-35mm f2.8 L USM II. But at f8 one will be hard pressed to tell those apart from for instance that Tokina.
And the FF-Tokina combination will beat an APS-C + Tokina 11-16mm f2.8 too, at f8...