Sigma's semantics

[HeldDown]

I see that Sigma makes "DC - Designed for Digital" lenses; their description says that the image circle is made so it closely matches the APS-sized sensors for crop-bodies. But does that mean their 18-50 is a *REAL* 18-50 on a 1.6x body, and not 28-80 like a normal 18-50mm would be?

I'm confused.

[HeldDown]

Does anyone ever ready my threads? :P

[TristanP]

But does that mean their 18-50 is a *REAL* 18-50 on a 1.6x body, and not 28-80 like a normal 18-50mm would be?

Sigma's DC line is essentially just like the Canon EF-S lenses. Smaller and lighter due to needing less glass to fill the smaller image circle of the APS-C cameras. The 18-50 is still subject to the 1.6x crop factor, so yes, it's a 28-80 equivalent in 35mm terms. Sigma's DG line is Optimized (rather than Designed) for digital (IIRC), so they'll work on full frame film and digital bodies, but have special coatings to reduce flare and ghosting on dSLRs.

[HeldDown]

Ah, thank you.