Originally Posted by ColorChange
Guy, as a general rule wider then 0.7 starts to really distort. Yes it's wide, but at a pretty fair cost. Some accept it, others like me don't. 0.7 is kind of a generally accepted best compromise, thus all the majors offering a 0.7 but few majors offering wider.
Obviously, the best way is to pixel peep side by side shots and decide.
got the century optics .55x converter in today and although i didn't actually shoot anything through it yet, i formed some quick impressions ...
you are right about the distortion. loads of barrel distortion at close distance. but i expected that.
what i didn't expect was having to turn off the insta-focus mode and go back to normal focus mode. you would think (or, i thought) that the external focus sensor would be a help, not a hindrance. but canon is right, i could find focus only about 5% of the time with insta-focus on.
using regular autofocus there was less hunting, but the focus is slower. and, as expected, focus was not attained past about 40% of the focal length. so at a rough calculation you would have what would, in the 35mm world, a nearly ideal ~24-80mm/~f1.8-2.5 lens. actually that was about what i had hoped in my original post.
i sure don't like having to go into the menu to change the focus mode. but, i've decided to keep the converter in spite of these negatives for the following reasons:
it's schneider and i doubt any better quality is available. very well built and includes back and front caps, a vinyl case, and step-down adaptors.
it's tiny, only a couple of mm's longer than a filter. fits in a cranny in my already small hv10 bag.
and i discovered that i could hit the 'focus' button to go into manual focus. since i mainly want this for panoramic vistas i suspect that most of the time i could hold the 'focus' button for 2s to go directly into infinity focus.
the bottom line is that in spite of the clumsy workarounds, they are worth it for the benefit of having a 24mm (43.6 * 0.55 = 23.98) lens coupled with the 16:9 format for those occasions when you can't have it too wide short of the fisheye look.
thanks for the help.