This was the only photograph I took today, and it really reminded me of a glass sheet hologram that I gave to my dad one fatherís day. However, part of the reason for that can be seen in the petal in the rear left of the photograph. If you look closely, you can see a bit of chromatic abberation, or colour fringing, where the blue light has come a little out-of-phase with that rest of the light.
This isnít generally typical of the Tamron 18-270 PZD, but you will see it if you zoom all the way in and focus as close as you possibly can, as was the case here. Working at these extremes does exaggerate the weaker points of the lens. This is one of the reasons why I like to use a close-up dioptre with this lens. You can select a more modest focal length, and benefit from sharper resolution. By adding an extra element, some of this is negated, but I have found that itís less severe than using the lens alone.
Nikon D300; Tamron 18-270mm PZD @ 270mm; ISO 200; F/11; 1/80s. VC on.