Lens Elements
- XR: Extra Refractive Index Glass (lighter, smaller lenses)
- LD: Low Dispersion (chromatic aberration reduction)
- XLD: Extra Low Dispersion (advanced chromatic aberration reduction)
- ASL: Aspherical (improved focal plane convergence)
- LAH: LD + ASL hybrid lens element
- AD: Anomalous Dispersion (improved control over chromatic aberration)
- ADH: AD + ASL hybrid lens element
- HID: High Index, High Dispersion Glass (minimizes lateral chromatic aberration)
This article is aimed to keep thing simple, there are many more abbreviations used by Tamron you can see them directly on Tamron official glossary http://www.tamron.eu/service/glossary/