12-08-2011, 08:53 AM
A bit silly, the nomenclature...
With Tamron, Di means "Digitally integrated". Not that there is all of a sudden something digital integrated as opposed to non Di lenses, but it basically means the coatings are re-formulated to combat purple fringing. Similar to Sigma's DG generation.
Di II means the same, but the II stands for "APS-C" lenses. So, lenses with a smaller image circle than the Di lenses, which are designed for 135 format.
And then now, Di III. Also for... APS-C. But a different mount. So now it does not stand for the image circle anymore, but rather for a shorter flange distance. Right...
With Tamron, Di means "Digitally integrated". Not that there is all of a sudden something digital integrated as opposed to non Di lenses, but it basically means the coatings are re-formulated to combat purple fringing. Similar to Sigma's DG generation.
Di II means the same, but the II stands for "APS-C" lenses. So, lenses with a smaller image circle than the Di lenses, which are designed for 135 format.
And then now, Di III. Also for... APS-C. But a different mount. So now it does not stand for the image circle anymore, but rather for a shorter flange distance. Right...