So Ive been using the A7III for like four years now and Ive always just stuck with my 24-70 GM but lately Im trying to do more nighttime street stuff here in Chicago and honestly the f/2.8 is just killing me with the noise. I need something way faster for these dark alleys but Im totally lost looking at all the G Master and Sigma options. My budget is around $900 and I gotta get this sorted before a project deadline next month and honestly Im sweating it. Ive never really committed to a single focal length before so Im scared Ill pick wrong. Which prime lens is actually the best balance for a Sony Alpha body when you need that extra light?
Honestly, if you are hitting those dark Chicago alleys, you need to jump to f/1.4 or you will keep fighting that grain. I remember being in a similar spot with my old A7II years ago, trying to capture neon signs in the rain. The f/2.8 zoom just didnt cut it. In my experience, the Sigma 35mm f/1.4 DG DN Art is the absolute sweet spot for your $900 budget. It is sharp as a tack and gives you two full stops over your GM zoom, which is huge when the sun goes down. I have tried plenty of glass over the years, but the rendering on that Sigma is special for street work. It feels substantial on the A7III too. If you are worried about picking the wrong focal length, 35mm is basically the gold standard because it lets you get the environment without looking distorted like a wider lens might. Another solid pick if you want to stay first-party is the Sony FE 35mm f/1.8. It is lighter and cheaper, but ngl, that f/1.4 on the Sigma is what you actually want for those midnight shadows... that extra light gathering really saves those shots. Quick tip: dont be afraid to use a slightly higher ISO even with a fast prime to keep your shutter speed at 1/125 or higher. Motion blur from camera shake will ruin a shot way faster than a little bit of sensor noise.
