Ive been shooting on my A7III for like four years now and usually stick to my 35mm prime but I just booked a wedding gig in Chicago for next month and realized I really need more reach without swapping lenses every two seconds. Im kinda panicking because my budget is super tight—max $850 after my Japan trip drained me.
So I was thinking maybe the Tamron 28-75 G2 is the way to go? My logic was that its sharp enough but then I saw the Sigma 28-70 is lighter and I have a bad wrist... but will the AF hunt too much during the ceremony? Im really stuck between the third-party options because Sony glass is just way too expensive right now. Is the Tamron actually reliable for fast movement or should I look at something else?
The Tamron 28-75mm f/2.8 Di III VXD G2 is absolutely the way to go for your A7III! I have used this lens for several weddings and the autofocus speed is fantastic. It is a massive upgrade over the first version and works perfectly for fast-moving moments during a ceremony. While the Sigma 28-70mm f/2.8 DG DN Contemporary is lighter, the Tamron feels more professional and offers better weather sealing which is huge for a Chicago gig. Honestly, the sharpness is amazing and it easily fits within your $850 budget if you shop around a bit. You wont regret picking this up... it really is a workhorse! The weight difference isnt that bad and the reliability you get in low light is just awesome.
