A lens will not increase the number of pixels of the camera. That is set in stone by the sensor. The OV5642 has more pixels but may or may not work with the ESP32 (You would have to check if it works for your use case).

Okay, thanks Steve, for clarification. I ordered two different camera sensor modules. 
The  OV5640-AF (auto-focus) is $13 at banggood.

 
And the OV7670 sensor module, about $4 at banggood:

I’m wanting to build a PIR-enabled outdoor bird feeder camera. Having a good wifi connection is a must, and an SD card reader. When a bird trips the sensor, it will take a picture per second and save to card. THEN, I need to make it web-enabled to view the stored pics. 

Whilst those are nice and cheap I foresee a problem interfacing with an ESP32 as it’s the camera only. You would need a connector to plug it into and then code to interface directly. If it were me I would probably have gone with something on a breakout board like this.

I was hoping I could just plug the new lens into the ESP32 module… well, I can hope.

Hi Donald. 
If you’re using an ESP32-CAM, I think you just need to replace the old lens with the new one and modify the code to work with the new camera probe.
Regards,
Sara