I have never been 100% happy with the distant focus on my otherwise-excellent Logitech C920 webcam. I found a super-easy, low-cost fix that extends the focal range considerably!
Here are the lenses I ended up using - they only cost me about $20: https://www.amazon.com/gp/product/B00...
Logitech camera settings software:
https://support.logi.com/hc/en-us/art...