Quote:
Originally Posted by jambo
Have a quick check:
Tamron use Di (Crop/35mm) and Dii (Crop only)
Sigma use Dx(Crop/35mm) and Dc (Crop only)
Jambo
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Quote:
Originally Posted by specialone
Mate, that means absolutley nothing to me 
Can you explain in simpleton terms?
Phil |
The whole Crop / 35 mm (full size, 24 x 36 mm) thing is about lens coverage for a given sensor size. The so-called "digital" lenses are usually designed to be used in lower end digital SLRs, with small size sensors (APS-C, 18 x 24 mm or thereabouts - Nikon D40, D60, D70, D80, D90, D100, D200, D300, D3000 and D5000).
This means they can be smaller in size (lighter and cheaper) since they don't have to cover as much area as the 'full size' ones (FX on Nikon speak). Confusion begins when Sigma use Dx for their 'full size' range while Nikon calls their 'crop range' DX.
In a nutshell:
You can use both on the D90, only 'crop' lenses will probably be cheaper, lighter, and have worse corner performance when compared to the full size lenses.