yo, honestly I would suggest looking at the more budget-friendly zooms before you drop like $3,000 on that GM glass. I’ve been using the Sony FE PZ 16-35mm f/4 G on my FX3 for a while now and honestly... the f/4 is totally fine because our sensors are basically low-light beasts anyway. If you're really worried about the speed, here's what I recommend:
* Tamron 17-28mm f/2.8 Di III RXD - This is basically the best value at around $700-$800 and the AF is actually super snappy.
* Sigma 16-28mm f/2.8 DG DN Contemporary - Another solid f/2.8 choice that won't kill your wallet like the Sony FE 12-24mm f/2.8 GM would. I mean, for real estate, you're usually stopping down for depth of field anyway right?? So spending $2k+ might be overkill. That 14mm prime is nice but ngl being stuck at one focal length on a gimbal is a massive pain. Just make sure to check the AF performance in low light before committing, but the Tamron has never let me down. cheers!

In my experience, you're actually safe with f/4 on these bodies because of that legendary dual base ISO at 12,800. Seriously, it's a game changer for low-light. If you're doing gimbal work on the DJI RS 3 Pro, the Sony FE PZ 16-35mm f/4 G is unbeatable because of the internal zoom—rebalancing is such a pain during fast shoots, lol. But yeah, if 16mm is still too tight for those tiny bathrooms, I'd lowkey look at the Sigma 16-28mm f/2.8 DG DN Contemporary. It's way cheaper than the GM glass, pretty light, and it takes standard 72mm filters so you dont have to mess around with those expensive rear-mount NDs like you would on the Sony FE 12-24mm f/2.8 GM. The AF is super snappy too, tho maybe like 5% less 'perfect' than native glass in extreme scenarios. For architectural stuff, that 2mm difference between 14 and 16 is actually pretty huge, so if you're really cramped, the Sony FE 14mm f/1.8 GM is the technical king even if it's a prime. Hope that helps!

tbh i realy agree with what was said about the ISO - those dual base sensors basically make it so you dont need to worry about the f-stop as much as we used to. I’ve been digging into the technical side of how these brands compare lately (im still kinda new to this so bear with me lol) and it seems like sticking with the native Sony ecosystem is generaly the safest bet for video. Like, they keep their proprietary AF algorithms locked down, right? So any native glass from them is gonna track way better than third party stuff - especially for high frame rate stuff on the FX3. Sigma is great and all, and their optics are realy sharp, but if you want that perfect "it just works" feeling, just get any of the Sony wide options. I mean... does the third party stuff ever truly catch up with the native communication speed? Probably better to just stay in the family if you have the budget for it. Plus, the resale value on the first-party stuff is usually way higher anyway.

Yep, this is the way

yo, honestly i get the struggle between wanting that ultra-wide look and not wanting to drain ur bank account on one single lens. for real estate and architectural video, the most important thing to understand is that you're rarely shooting wide open anyway. i mean, even if you have a fast prime, youre usually stopping down to f/5.6 or f/8 to keep the whole room in focus, so obsessing over f/1.8 or f/2.8 is kinda overkill for that specific niche. plus, on bodies like the FX3 and a7S III, that high ISO performance is literally insane. you can comfortably bump your gain and the image stays clean. so, here is my take: i would suggest looking at the third-party manufacturers like Sigma or Tamron. honestly, their AF has gotten so good that it basically feels native now. you can get a really solid wide-angle zoom from those brands for like half the price of the G Master glass. if you go with a third-party zoom, you get the versatility of different focal lengths which is HUGE when you're in a tight bathroom or kitchen and need to frame things quickly. plus, most of them use standard filter sizes so you wont have to deal with those massive, expensive rear filters or adapter rings. anyway, for professional work where ROI matters, i highkey think the value you get from the third-party options is the way to go. it just works and saves you a few grand. peace ✌️