Building on the earlier suggestion, the Sigma 56mm f1.4 DC DN Contemporary is definitely the way to go for the price. I've run some tests with the Fujifilm X-T30 and the sharpness is honestly top tier for the money. If you are worried about tracking kids running around, just make sure your firmware is current. The consistency is great for family shots and you wont be disappointed.

Honestly, just grab the Sigma 56mm f1.4 DC DN Contemporary and dont overthink it. People online love to obsess over tiny sharpness differences that you wont even notice in real family photos. I picked one up for my own kit last year and Ive been super happy with the results. Here is why it works so well for family stuff:

• The autofocus is snappy enough to catch kids running around the yard.
• Size-wise, it balances really nicely on smaller bodies like the X-T30 without feeling front-heavy.
• Low light performance is great for indoor dinners where flash isnt allowed. Build quality feels solid too, no complaints at all after taking it on several trips. Viltrox makes decent glass for the price, but Sigma's tracking reliability made the decision easy for me. You will get gorgeous background blur and sharp portraits without draining your wallet before the trip.

Re: "Honestly, just grab the Sigma 56mm f1.4 DC..." - totally feel that, but just watch out for focus breathing if you end up doing any quick video clips of the fam running around. I learned that the hard way at a birthday last year. Make sure to update the firmware right away too. If you want something slightly different, the Viltrox AF 56mm f1.4 XF has a nice mechanical aperture ring that feels super vintage if youre into that tactile vibe.

Works great for me