So the previous suggestions cover the extreme focal ranges well, but from a reliability-first perspective, you gotta think about build quality and weather sealing. Those high-ratio zooms like the 24-240 have a lot of moving parts that can eventually lead to zoom creep or dust ingress—pretty risky if youre traveling hard or shooting in unpredictable conditions. If you want something thats basically bulletproof on an a7 IV, here are my top picks for a single-lens setup: * Sony FE 24-105mm f/4 G OSS - This is the industry workhorse. Constant aperture, pro-grade weather sealing, and it doesnt suffer from the soft corners you often see with super-zooms. It handles the 33MP sensor perfectly.
* Tamron 35-150mm f/2-2.8 Di III VXD - A bit heavier, but the VXD linear motors are incredibly reliable and fast. Its basically a bag of primes in one housing. Honestly, Id take the 24-105 G over a 10x zoom any day. You lose some telephoto reach, but the peace of mind knowing your gear wont fail in a humid or dusty environment is worth the trade-off. Plus, the a7 IV has enough resolution that you can just use Super 35 mode or crop in if you really need that extra reach.

For a versatile all-in-one zoom on your Sony a7 IV, consider the Tamron 28-200mm f/2.8-5.6 Di III RXD. It offers a broad focal range and a bright f/2.8 aperture at the wide end, all in a compact design. Alternatively, the Sony FE 24-240mm f/3.5-6.3 OSS provides a 10x zoom range, covering wide-angle to telephoto needs. While convenient, these lenses may exhibit slight compromises in sharpness compared to prime lenses, especially at extreme focal lengths.

FE 24-240 is recommended.

Just saw this thread and it brings back memories of when I was scouring every corner of the internet trying to decide between staying native or going third-party for my a7IV. Honestly I spent months looking at market trends and comparing how different brands handle their lens tech because the price gap is sometimes just insane and I really went down the rabbit hole of brand loyalty versus budget and it was basically a headache trying to figure out if the extra cost for the 'official' glass was actually worth it for my specific travel needs. What I looked at during my research:
* Firmware update ease between the body brand vs the third parties
* How the colors look straight out of camera across different manufacturers
* The resale value because some brands seem to hold their price way better than others idk I eventually grabbed a third-party lens and it's been okay for my setup but tbh I still wonder if I should have just stuck with the native ecosystem for that perfect autofocus sync maybe? It's always a gamble when you're trying to balance value and performance.