Tamron 28-75mm 2.8 Di III RXD für Sony E

The 28-75mm F2.8 Di III RXD is Tamron's first ever lens for Sony's range of full-frame mirrorless cameras. This new standard zoom features a constant aperture of f/2.8 throughout the range, an impressive minimum focus distance of 0.19m, an all-new RXD (Rapid eXtra-silent stepping Drive) focus motor for quiet and fast AF operation, and a moisture-sealed construction. The optical formula is comprised of 15 elements in 12 groups, including 1 XLD (eXtra Low Dispersion) element, 1 LD (Low Dispersion) element, 1 GM (Glass-Molded aspherical) element and 1 hybrid aspherical element, and it has an iris diaphragm with nine rounded aperture blades for better bokeh effects. The Tamron 28-75mm F2.8 Di III RXD lens officially retails for £699 / $799 in the UK and USA respectively.

It is easy to spot why the Tamron 28-75mm f/2.8 Di III RXD is so popular. There is, of course, the moderate price tag combined with the fast max. aperture which sets it apart from Sony offerings. Optically it is decent - for such a lens - albeit it comes with a couple of carefully placed compromises. At the wide-end of the zoom range, it is quite sharp across the image frame when stopped down to medium aperture settings whereas the center performance remains superb at 75mm which is where you'd typically use a large aperture setting anyway. Thus the mainstream settings are offering quality where usually needed the most and you will probably agree that most of the provided sample images actually look very decent. That being said, technically there are also obvious weaknesses when using the lens on a high megapixel camera. The corner performance isn't all that hot at large-aperture settings and for a sharp result across the frame, you should stop down to f/8 or f/11. While you can certainly achieve decent object isolation via a shallow depth-of-field, the quality of the bokeh can be quite rough in difficult scenes - when shooting at f/2.8 at least. As far as image distortions, vignetting and CAs are concerned, most users will rely on image auto-correction thus you can live happily ever after. If you look behind the scenes - thus into the unmodified RAW image - you can spot medium distortions at the extreme ends. Lateral CAs are fairly low at the image borders but intensify in the extreme corners. The vignetting is also high at 28mm f/2.8 and 75mm f/2.8 albeit this isn't unusual in this class. The build quality is on a very decent consumer-grade level. We are not convinced that the smooth finish will stand the test of time without scratches but out-of-the-box it certainly looks good (albeit a bit long-ish). An annoyance is the tendency of the rubberized zoom ring to function as a dust-magnet in no time. The moisture-resistant design is certainly a plus. A highlight is the fast and silent RXD AF motor. Some users will surely also appreciate the close focus capabilities of the lens which is a classic value-add on many Tamron lenses. If you can't or don't want to afford the Sony FE 24-70mm f/2.8 GM but still want an f/2.8 standard zoom lens, the Tamron is a good and light-weight option IF you can live with the rather moderate 28mm setting at the wide-end.

The Tamron 28-75mm f2.8 is a valuable addition to the full-frame E-Mount market, that's wisely pitched between Sony's entry-level FE 28-70mm f3.5-5.6 kit zoom and the high-end FE 24-70mm f2.8 G Master. The Tamron is stunningly sharp in the APS-C image-circle and delivers very usable close-up performance too. It's small and light and comes at a reasonable price that makes it a viable option for those who can only dream of f2.8 zooms and were otherwise heading to the budget kit lens. For the price, the sharpness unsurprisingly becomes softer in the full-frame corners and many will miss the wider coverage of zooms that start at 24mm; there's also some irritating flare and ghosting under certain circumstances. But all-in-all the Tamron 28-75mm f2.8 is an attractive option for E-mount owners who want a step-up in aperture from the entry-level Sony FE 28-70mm f3.5-5.6 kit zoom without the considerable cost of the FE 24-70mm f2.8 G Master - and while it may become soft in the corners, subjects towards the middle will be sharp with the potential for attractive blurring behind them. So overall I'm happy to award Tamron's first native E-mount lens a recommendation!