Hi ____Max183,
I understand you need to stand closer to the subject in order to take a clear photo.
As stated here: Use camera modes on your iPhone, iPad, and iPod touch,
'Your camera automatically focuses the image and adjusts the exposure based on what you’re pointing it towards. That way, you always start with a brightly lit photo.
You can change the camera focus and exposure to a specific area. Before you take the photo, tap the place on the screen that you want to adjust. If you want to keep the focus and exposure in the same spot, press and hold on the screen until you see AE/AF Lock.'
I would recommend trying a manual focus to see if this resolves your issue. It's possible that due to the lack of lighting contrast between the subject and the background, the iPhone is unable to focus automatically as expected.
Hope this helps!
Thank you for using Apple Support Communities.
Cheers!