Well now, that depends on which Canon lenses you buy - from personal
experience, every L-series lens I have used does not at all depend
on "calibration" as to whether it is parfocal or not - it all boils down
to mechanical engineering and precise metal helicoids. I know this is
an Olympus list (and the fact that I sold all my Canon EF gear and
replaced
it with OM gear gives me, I think, a right to comment on the relative
merits of both systems) but there is no denying that most of the L-
series lenses
are optically and mechanically absolutely superb.
This is a completely different story to the more "modern" focus-by-wire
designs the new Olympus lenses have which may depend on calibration,
but the
Canon lenses (except the few focus-by-wire lenses from the late 80s) are
all fully mechanical.
On the other hand, there is no denying that the consumer-grade canon
lenses
are built like toys, whereas cheap Olympus lenses are built a bit
better (but
not much).
On 11 Jun 2009, at 6:06 PM, C.H.Ling wrote:
> A slower lens will help a little but this is not the key. Fine
> calibration
> is required if you wanted to ensure no focus shift during zooming. I
> calibrated many Zuiko zooms (and also the two Tamrons I just
> acquired) in
> order to ensure the focus does not change during zooming, this is more
> critical for the wide zooms.
>
> I suspected the modern AF lenses are more difficult to ensure for this
> aspect as the AF mechanism (lens element group) need some space for
> movement
> (can't be too tight). I see some lenses even have different
> sharpness from
> left to right side, this including a Tamron 28-300mm, DZ 11-22mm,
> Tarmon
> 24-135mm, DZ 14-42mm. I also heard some stories about the poor quality
> control/standard of Canyon, people keep purchasing the lens until
> they found
> a best one, the rest just sell it out.
>
> C.H.Ling
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|