You gotta get the Sigma 30mm f1.4 DC DN Contemporary for Fujifilm X. Its absolutely fantastic for low light! That f1.4 aperture means you can shoot in your dark house without it looking grainy, and the background blur is just gorgeous. It fits your budget perfectly and is way better than the kit lens. Seriously, itll make those birthday photos look pro!

Jumping in here... unfortunately, I've had some real issues with off-brand lenses lately. They look great on paper but in a dark living room with a toddler? They kinda struggle. I bought a third-party lens last year and the autofocus was just not as good as expected. Honestly, it was super disappointing because it basically ruined half the birthday photos by hunting for focus while my son was blowing out his candles. If you want total reliability and something that wont fail you, I'd stick to the native Fuji glass. For $400, you can usually find these:

• Fujifilm XF 23mm f2 R WR
• This is wide enough so you can get the whole scene indoors.
• Fujifilm XF 35mm f2 R WR
• Really sharp but might feel a bit zoomed in if your house is small. Check out the reviews on a site like OpticalLimits or Dustin Abbott. They show real-world performance so you dont end up wasting money on something finicky. Couple quick tips for the party:
• Keep your shutter speed at 1/200 or 1/250 minimum. Kids move fast and you dont want motion blur even with a fancy lens.
• Make sure Face and Eye detection is turned on in your menu. The X-S20 is amazing at tracking kids if that setting is actually active. It's a bit of a learning curve for sure, but sticking with the original Fuji stuff is just way safer for big events imo...

TL;DR: Low light photography is honestly a massive money pit and super frustrating, but generally, sticking with any fast prime from Fujifilm is going to be your safest bet for that blurry background look. I totally feel your pain on this. I’ve spent way too much time obsessing over MTF charts and optical performance data only to be let down in the real world. A few years back, I tried to shoot a holiday party in a dim basement with what I thought was high-end glass, and it was a total nightmare. The autofocus was constantly hunting, and unfortunately, the bokeh everyone raves about just looked like a messy, nervous blob because the lens construction wasnt as good as expected. It's so discouraging when you spend hundreds of dollars and the technical performance just isnt there when the lights go down. I had major issues with some third-party options too where the colors just looked off compared to the sensors natural output. Its honestly exhausting trying to find that perfect balance between price and actual usable quality. Honestly, just look at the Fujifilm Fujinon XF Prime Lenses or even the Viltrox AF Prime Lenses lineup. You basically cant go wrong with any of their faster glass if you want that blur, even if the technical flaws in cheaper lenses drive me crazy sometimes. Just keep an eye on your shutter speed or the kids will still be blurry anyway... its a constant struggle, ngl.

^ This. Also, I've had issues with trying to go for the most pro looking lens only to realize it's basically useless in a small house. I bought a fast one for a similar situation years ago and it was honestly not as good as expected. I spent the whole party literally backing into walls trying to fit my family in the shot. It was super disappointing and I missed the cake cutting because the focus kept hunting in the dark. My current setup is way wider now because honestly, those tight lenses are a nightmare for indoor parties. TL;DR: Stick to 23mm. Anything longer and you'll just be taking photos of peoples noses all night.

> i just want something that makes the background blurry and works in low light. I went through this exact mess last year. I bought a lens with a low f-stop for my kids party and found out the hard way that some lenses are basically like telescopes indoors. It worked for the blurry background, but i couldnt fit everyone in the frame. A wider 23mm is usually safer for cramped living rooms than a 35mm or 50mm.

Would love to know this too

Can confirm

Solid advice 👍