The fourth prompt in Genshin Impact's Graph Adversarial Technology Experiment Log event is Staff-Wielding Opponent. You can easily find these all over Teyvat by searching for Samachurls and shielded Hilichurls.
While there are a ton of Hilichurls in the game, their variations are scattered across the map. I'll show you some easy-to-find places beside Teleport Waypoints, so you can take all 10 photos for the day in just two minutes.
Genshin Impact Staff-Wielding Opponent locations – Graph Adversarial Technology Experiment Log
While exploring, keep your eyes peeled for Hilichurl Fighters, Shield Hilichurl Guards, and Samachurls, as they wield the staff-like weapons required for the day's image samples. Visit any of the locations below to find the required Hilichurls.
Head to the Domain in Wolvendom to find two groups of Hilichurls on the left and right. Both groups will have variations of staff-wielding Hilichurls, so take photos on both sides!
Head to the Teleport each of Wolvendom, then go slightly northward so that you're facing the shore. You'll find a group of Hilichurls, including Samachurls that can be photographed for the day.
Head to the Teleport Waypoint in Stormbearer Mountains. Zoom into the small lake up ahead to find a Samachurl, which you can take a photo for the day's prompt.
From the Stormbearer Mountains Teleport Waypoint, I recommend going further north to find a group of Hilichurls lounging with a Slime. Here, you can take a few photos to count toward the photography prompt.
Head to the Teleport Waypoint north of Stormterror's Lair, then climb the stairs behind it. You can take a photo of a Samachurl beside a Mitachurl.
Head to the Teleport Waypoint in Starglow Cavern and look down to find Hilichurls. You can take a photo of the Ice Shield Hilichurl Guard for a higher chance of getting blue-toned image samples.
To complete more photography prompts, check out Where to find Basically Blue Wild Creature in Genshin Impact – Graph Adversarial Technology Experiment Log here on Pro Game Guides.