Now it happens that my laptop does not have a camera and I have connected my mobile phone camera to the PC in order to be able to use a camera live. Both cameras on my cell phone can be set to 720p, which means that I only ask myself, taking into account the power consumption and the load on the cameras, whether it would be better to use the main or the front camera?
I mostly use the front camera. Unfortunately, the quality doesn't take much because of the compression, but you can see yourself and still see notifications.
If you take the power consumption as a comparison, the front camera had to be better.
The front camera is usually smaller. I mean the physical size of the sensor. A smaller sensor should use a little less power.
The front camera often also has a lower resolution. So fewer pixels have to be read out. Even if a 720p picture comes out at the end, all pixels (in 16: 9 format) must be read out. The image is then downscaled.
The power consumption for processing the video is the same or similar for both cameras. The raw data from the video must be processed and ultimately processed into a 720p video with the appropriate resolution. The transfer via USB or WLAN is of course also included.
In the end, the difference should be very, very small.
Even if you can only use 720p video, your main camera should be able to provide a better picture. A presumably larger aperture (smaller number) and the larger sensor ensure a greater depth of field, which looks a little better. Both factors also ensure lower noise, which will be visible in weaker light.
The main camera usually has that. Better quality than the front camera. The picture will look better and also sharper.
The fact that you can't see the display of the cell phone should be irrelevant. I suspect that you can see a preview of the picture on the laptop.
It is best to use the main camera.
Since you did not name your smartphone, it is not possible to make a 100% precise statement. Every smartphone has built-in different sensors and lenses / lenses.
I would choose the camera that shoots less wide-angle. Distortions are then less pronounced.
The question of power consumption is irrelevant if the app (such as IVCam or DroidCam, for example) supports a USB connection and is also used.
The picture is also more stable via USB than with WLAN.
