Hi Mike and all,
From: usher99@xxxxxxx
>Kinda liked the below explanation of terms. The CV 125/2.5 Apo-Lanthar
>shows some CA in in the foreground OOF area if there is a sharp edge of
>contrast at 1:1 esp if on the Mirex T-S adapter. Perhaps this is a special
>OOF CA.
Most likely longitudinal CA -- unlike lateral colour, basically impossible
to correct via software :-(
>APO clearly does not = NO CA under all conditions.
Absolutely -- just a better degree of correction.
<http://toothwalker.org/optics/chromatic.html>
A very interesting site... it however lacks an explanation of
spherochromatism -- the variation of spherical aberration against
wavelength.
Anyway, I wouldn't test CA on heavily overexposed areas -- either on film or
digital. CA has real existence, but in _some_ cases could be just lateral
halation/bleeding or other film/sensor issues.
Cheers,
-- Carlos J. Santisteban Salinas
IES Turaniana (Roquetas de Mar, Almeria)
<http://cjss.sytes.net/>
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