The announcement of a new full-frame 16-30mm F2.8 wide-angle zoom lens from Tamron has inspired me to discuss the topic of lightweight wide-angle lenses in more detail. Hopefully this discussion will help you in your own purchasing decisions.
For more support on this topic of lens choice, check out the extended 'Lens Choice 2' seminar, available from the Collections section of this Patreon support channel : https://www.patreon.com/posts/81162455?collection=34689
Tamron, Sigma and Sony all have lightweight alternatives to the ever-popular 16-35 F2.8 wide-angle zoom lenses. The concept of offering these smaller, lighter and cheaper options, with a reduced focal range, is because most photographers have a standard zoom that starts its zoom range at either 24 or 28mm, so there is no need for the 'overlap' in focal lengths with a wide-angle that has a maximum focal length of 35mm, e.g., the popular 16-35 zooms.
Given that one of the advantages of these 'reduced focal range' wide-angle lenses is size, weight and cost, I though it would be useful to compare the specifications of the Tamron and Sigma lenses with Sony's own reduced focal range wide-angle zoom, the FE 16-25 F2.8 G and also Sony's wide-angle prime, the FE 16mm F1.8 G. Sony's 'full-sized' FE 16-35 F2.8 GM lens weighs in at 1.5 lb and costs just over US $2,000. I have not included this in the comparison chart as it is not built to compete with the smaller, lighter and cheaper offerings.
Both the Tamron and Sigma wide-angle zooms are significantly cheaper than Sony's FE 24-50 F2.8 G and also have a greater zoom range. One could argue that the smaller zoom range of the Sony wide-angle zoom is not significant, especially if you have a standard zoom that starts its zoom range at 24mm, e.g. the FE 24-50 F2.8 G or FE 24-70 F2.8 GM. The longer reach of the Tamron and Sigma lenses is primarily because the standard zooms from these companies sometimes start their zoom range at 28mm rather than 24mm.
So are there any advantages in paying more to own the Sony wide-angle zoom lens over the more affordable Sigma and Tamron alternatives? As you can see from the comparison chart, there are some advantages to owning the more expensive Sony option, including a greater number of aperture blades for smoother bokeh, a closer focusing distance for an improved magnification ratio for close-up photography, an aperture ring that can be 'de-clicked' for videography work, support for 'Focus Breathing Compensation' and 'Dynamic Active Steadyshot' (recently added to the A7CII and A7CR cameras with the version 2.00 firmware update) + support for fast frame rates when using the A1 II and A9 III cameras . The Sony also has a 10% size and weight saving over both the Tamron and Sigma options.
You may be wondering why I have chosen to add Sony's FE 16mm F1.8 G prime lens to the comparison chart. This is because the Sony 16mm prime is my personal choice for a lens with an ultra-wide angle-of-view (especially when working with one of the full-frame compact camera bodies, such as the A7CII and A7CR). The 16mm prime is smaller, lighter and cheaper than all of the zooms I have mentioned. It also has the advantage of having a brighter F1.8 aperture and a superior close-focusing distance. If I need to zoom, I can either crop in post, crop in camera using APS-C mode or use 'clear image zoom' when shooting movies. All of these options will comfortably take me up to then standard focal range of my lightweight FE 24-50 F2.8 G lens. I do not see cropping as a disadvantage as I rarely create exhibition-sized prints.
All of the lens options outlined offer good value for money, in my opinion, and there are definitely no right or wrong choices. Photographers will be drawn to choosing a particular lens because of differing priorities and maybe because some of the advantages highlighted in the comparison chart are not important to their own workflows. I have only chosen to raise this topic because many reviewers of the new Tamron 16-30 F2.8 G2, will inevitably try to 'sell' the new Tamron as the perfect lens for travel photographers. It is useful to remind ourselves that the message peddled by some lens reviewers is that owning one more lens will, in some way, make us a better photographer. We have to continually question this sales-pitch before we dive in to make a purchase.
Lens Reviews
FE 16mm F1.8 G: https://youtu.be/9hyNS0Wf0Qc
FE 16-25 F2.8 G: https://youtu.be/9P369tG2pMs