The 180mm f/2.8 rather simple schema (obviously non-APO) is supposed to have
many nice optical features but one big drawback: the bad CA control, and
this will show up in the entire frame, not only in the corners.
In my sample the CA shows clearly, even in small (10x15 cm) prints: that is,
it is definitely perceivable...
C.H. Ling showed that closing the diaphragm to f/8 (if I recall correctly)
greatly reduces the problem. So, if you shot at f/4, either your 180mm f/2.8
is not a 180mm f/2.8 :) or it benefits from having a digital sensor at its
back end (in which ways, I do ignore).
Regards and thanks for the info!
On 3/21/06, Daniel Sepke <dan@xxxxxxxxx> wrote:
> Hi Fabio,
> Thanks for your comments.
> I have not seen the chromatic aberration problem so far but I have only
> the lens for a few weeks. Looking at the edges at 100% in the original
> I don't see anything objectionable, a hint of glow on some of them but at
> the sizes I am going to use these at it presents no problem. They where
> at f4 mostly with 400 iso and in A mode.
> As far as the popularity of soccer in the US goes its all about the
> game round here. Coming from the UK it took a little getting used to
> not that I was much of a footy buff back there. High School soccer is
> popular and just a fiercely played as any game I saw in the UK. I think
> game got a big boost in the late 90's though it is no way near the rest of
> the world yet.
> Thanks, Dan S.
> Fabio wrote:
> Daniel, did you notice any blue or purple halo around light subjects in
> full size shots? Judging from these reduced images everything seems OK,
> I wonder why that (in)famous "cromatic aberration problem" the 180 f/2.8
> so renowed for has not shown up this time... :)
> Do you remember the aperture you took these shots at?
> Thanks for your help!
> And now a slightly OT question: do you confirm that soccer is growing in
> popularity there in the USA, especially in High School and colleges? Just
> curious about that (you know, common folklore says that here in Italy we
> bread and soccer, so I can't prevent myself from asking... :)
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