Late to the party but @Reply #2 - good point! In my experience, heavy glass just ruins the vibe. I did the Tetons with a massive kit once and honestly just wanted to quit by day three. To keep it under that 900 buck limit:

• Sigma 28-70mm f/2.8 DG DN Contemporary is way lighter and cheaper.
• Tamron 28-200mm f/2.8-5.6 Di III RXD is the king of versatility for Yellowstone.

Saw this today and figured id weigh in since i use the same setup. These two options fit your budget and performance needs:

• Tamron 28-75mm f/2.8 Di III VXD G2 offers a fast f/2.8 aperture for better low light and background blur.
• Sony FE 24-105mm f/4 G OSS provides more focal range for those wide Yellowstone landscapes. The Tamron is generally the sharper pick for kids tho.

Honestly, I totally get the frustration. Primes are great for art or whatever but for real life? Theyre kind of a nightmare when kids are running around. I made that exact same mistake when I took my Sony a7III to the Grand Canyon last year. I thought Id be fine with just a 50mm because everyone raved about it, but honestly, it was a huge disappointment. I spent half the time backing up into rocks and the other half wishing I could actually zoom in on my kids before they ran off. Whatever you do, please dont get sucked into those massive all-in-one zooms that try to cover every single focal length from wide-angle to crazy telephoto. I tried one of those mega-zooms a few years back and it was honestly a massive letdown. The images were soft as butter at the long end and the autofocus just couldnt keep up with my kids. Youre gonna see some cheap options that promise to do everything for like 400 bucks, but trust me, you wont be happy when your Yellowstone shots look blurry. You basically want a solid mid-range zoom that stays around a constant aperture. Just be careful buying used gear from random people too... I got burned on a perfect lens once that arrived with a nasty fungus spot right in the middle of the glass. Stick to the reputable shops even if it costs a bit more.

To add to the point above: i am honestly in the exact same boat and it is so stressful. i am super happy with my Sony Alpha 7 III but this lens situation is a total mess. i have been dealing with this for like three months now and still havent pulled the trigger on anything because i am terrified of making the wrong choice for our big trip.

• i have been scouring the buy and sell boards on Fred Miranda daily
• spent way too long looking at real world samples on flickr groups
• checked every travel zoom comparison on the DPReview forums it is just such a headache when you want that professional look but need the convenience of not carrying a massive bag. i took my kit to the local zoo last week and basically missed every shot of my kids because the 35mm just couldnt reach... i was literally standing in the way of other people trying to get close enough and still failed. it is really frustrating tho because the camera itself works well, i just cant find the glass to match. i am so over it.

just saw this and had a thought... yellowstone is a different beast compared to just running around the park at home. before you sell that prime, are you mainly wanting to zoom in on the wildlife like bison or are you more focused on the wide landscape shots with the kids in the frame? that really changes what kind of range you should look for. couple things i would suggest:

• be careful with the heavier glass because hiking those boardwalks gets old fast if your kit is dragging you down
• go with tamron for the best value, honestly you cant go wrong with their newer stuff and it saves you money for gas and snacks
• make sure to double check if the lens is weather sealed since yellowstone can get pretty dusty and unpredictable tbh i might want to consider staying away from the super expensive sony native lenses for now. third party brands are totally fine and way easier on the wallet while giving you basically the same results for family photos...

I am in the exact same boat and it honestly sucks. I tried doing a big trip to Zion with just a 35mm and I spent the whole time feeling like I was failing as the family photographer because I could not get a single good shot of my kids near the river without being right in their faces. Sadly those primes are just too limiting for real-world travel when you are chasing people around. Since you are looking for that one-lens setup under 900 bucks, you might want to look at these since they are a bit different from the usual suspects:

• Sigma 24-70mm f/2.8 DG DN Art
• You can occasionally find these used for around your budget. It is way heavier than the Tamron alternatives which is a bummer, but the image quality is miles ahead of most mid-range zooms.
• Sony FE 24-240mm f/3.5-6.3 OSS
• If you really want that never take it off vibe for Yellowstone wildlife, this covers everything. Sadly it is not as sharp as an f2.8 lens, but the range is basically unbeatable for a single lens solution. Tbh the native Sony G-Master glass is usually way too expensive for what you actually get. I would definitely look at Sigma if you want that professional look without the insane price tag. Good luck with the trip, Yellowstone is amazing but definitely a workout for your gear!

jumping in here because i totally agree with what was said about the stress of missing shots while fumbling with gear. honestly i spent years being that person with a massive bag of glass thinking it made me a better photographer. in my experience, it just makes you a frustrated parent. i did a week in glacier a few years back and tried to stick to my purist roots with only primes. it was a total disaster. while my kids were pointing out a moose, i was frantically digging through my bag for a longer lens. i ended up missing the best moments because i was too worried about having the perfect focal length. after that trip i realized a few things:

• the best photo is the one you actually take
• kids dont wait for you to swap gear
• carrying ten pounds of glass is a quick way to hate hiking i eventually swapped everything for one high-quality zoom that basically lives on my camera now. it isnt quite as fast as my old favorites but the trade-off for my sanity was 100% worth it. honestly, the peace of mind knowing i can just point and shoot without missing a core memory is way better than any marginal sharpness i got from those primes... definitely wish id done it sooner.