Yo, just found this thread! Honestly, I went through this exact same crisis when I first grabbed my a7 IV. I spent way too many late nights obsessing over MTF charts and corner crops... I eventually learned that 90% sharpness is usually plenty, but 100% weight is always too much lol. Check out **Sony Alpha Blog** (Marc Alhadeff’s site). It’s an incredible resource where he charts lenses by sensor resolution. It’ll tell you exactly which glass can actually resolve those 33 megapixels properly. Here is a quick technical breakdown of ur options: - The Sony FE 24-70mm f/2.8 GM II is insane because of its four XD Linear Motors. If ur shooting family trips with fast-moving kids, that AF tracking is highkey the best in the game. - If the GM is too pricey, you gotta look at the Sigma 24-70mm f/2.8 DG DN II Art. Make sure to get the "Mark II" version tho! It’s way lighter than the original (745g) and handles much better for all-day carry.
- The Tamron 28-75mm f/2.8 Di III VXD G2 is the value king, but honestly, be careful with the 28mm wide end. For street photography, that 4mm difference from 24mm is actually HUGE when you’re in tight alleys. I would suggest using the comparison tool on **The-Digital-Picture** to see side-by-side crops before deciding. Basically, if you can swing the cost, the GM II is the perfect balance of weight and tech. GL!

In my experience, picking glass is basically weight vs cost. - Grab Tamron 28-75mm f/2.8 Di III VXD G2 for $700.
- It's only 540g.
- Sharp enough for ur 33MP sensor. Honestly, it's a total steal!

Curious about one thing: do you NEED 24mm? Honestly, the Sigma 28-70mm f/2.8 DG DN Contemporary is way lighter and cheaper than the Art... definately a decent value option for ur Sony a7 IV.

Honestly, I’ve been looking at how the market has shifted lately and it’s pretty wild how much the gap between brands has closed. If you’re mostly worried about how the lens talks to the camera - especially with that a7 IV autofocus - you pretty much can’t go wrong with sticking to Sony glass. They definitely keep the fastest response times for their own stuff, which is what you’re paying that premium for. On the flip side, looking at it from a market perspective, the third-party manufacturers have really stepped up. I’ve always felt like Sigma leans more towards that high-end, heavy-duty build quality that feels super solid in the hand, whereas Tamron seems to be focusing way more on the ergonomics and keeping things light for travel. Tbh, you’re basically choosing between 'ultimate performance' and 'real-world usability' at this point. If you’ve got the budget, go with the native brand, but if you want to save some cash for your next trip, the other big names are honestly catching up so fast it’s hard to tell the difference in the final shots anyway. It just depends on what brand philosophy you're vibing with.

Bookmarked, thanks!

Just saw this thread and it reminds me of how I used to obsess over gear. I actually tried to DIY my own zoom by carrying a bag of cheap vintage primes I found at a garage sale. It was a nightmare to swap them during family walks but it taught me that I actually prefer a lighter kit over perfect image quality.

• I think a constant f/4 zoom might be your best bet if you want to keep things light for all-day carry. IIRC the weight difference is pretty noticeable when you're walking miles in a city.
• Not sure if it's still true, but I heard some people actually prefer the travel zooms that cover a huge range like 24mm to 200mm. They aren't as fast, but for outdoor family stuff, you might not even notice.
• Someone mentioned to me once that the a7 IV sensor is good enough that you can just use a wider lens and crop way in, basically giving you a digital zoom without carrying extra glass. Honestly, I eventually stopped worrying about the technical specs and just went with what felt best in my hand. If it's too heavy, you wont end up taking it out anyway.

^ This. Also, just catching up on this thread and honestly its kinda disappointing how much we have to compromise between weight and aperture lately. I had issues with those heavier f/2.8 zooms where they just felt too bulky for a casual stroll, which basically ruins the point of having a nice camera for family stuff. The discussion so far is spot on about the 24-70mm battle, but if you're open to something different, these might actually be better for long-term use:

• Sony FE 20-70mm f/4 G: Having 20mm for street photography is huge. Unfortunately the f/4 max aperture is a bit of a letdown in dim restaurants, but the size is perfect.
• Sony FE 24-105mm f/4 G OSS: The extra reach at the 105mm end is so much more useful for kids playing at a distance than the f/2.8 you get with the others. It sucks that there isnt one perfect lens that does everything, but dont let the gear stress get to you... just pick one and go shoot!

tbh choosing between native sony glass and third party brands like sigma or tamron is just the absolute worst part of this hobby. i spent weeks agonizing over the exact same thing for my own kit and it honestly just made me want to quit photography for a minute lol. the trade-offs with autofocus and weight between all these different manufacturers are enough to give anyone a massive headache. honestly tho just look it up on youtube... i saw a really good video the other day comparing all the major zooms for the a7 iv and it goes into way more detail than i ever could here. just search for something like sony a7iv mid-range zoom shootout and it should be one of the top results. it really helped me see the real world differences between the brands without having to read a million forum posts.