Camera Issues

[particlez]

Hi there. So my LG V30 has some issues with the camera. One the preview of the picture before i take the picture is TERRIBLE. I mean it looks like a camera from 2006. Once i take the picture the post processing makes it look nice, however the issue is when i do video calls theirs no post processing so it looks really bad.

 

[Mooncatt]

The reason the preview can look terrible but give a good final image has to do with the shutter abilities between the two functions. The preview is limited on exposure time (likely 1/30" or so) so it can do real time updating of the scene. To compensate, it increases the ISO to make it appear brighter. This gives you smooth video at the expense of lost quality. When you actually take the photo, now the exposure can stay active as long as necessary and with a lower ISO for a sharper image. So it's not really post processing making the image better, but rather a physical change in how the image is captured.

The reason the video calls look bad is due to the same reason live preview looks bad. Your lighting is too dim and your exposure time per frame is limited. The only thing the app can do at this point is raise the ISO, which also generates tons of noise. No amount of post processing can fix it and still look presentable. Your only solution is to increase the amount of lighting during a video call.

 

[particlez]

So it's normal for all androids to have bad previews and video calling?

 

[Mooncatt]

So it's normal for all androids to have bad previews and video calling?

I can't speak to video calls across the board because I've only used it twice, so I'll give you a broad explanation of photos vs video in general.

When you take a photo or video, it's all about gathering light. The longer the sensor is active, the more light it gathers, and the brighter the final result will be. Because a photo is a single image, the exposure time can be whatever you want (pro level cameras can expose for minutes on a single image). The lower the lighting the longer the exposure needs to be to achieve the correct outcome.

With video, it's effectively taking a photo about 30 times a second, aka the frame rate. That means the absolute maximum individual exposure time is 1/30". In good lighting, this may be fine. In low light, you cannot increase the exposure time without overlapping the frames, or showing a blurry slideshow. I.e. A photo requiring 1/5" exposure would mean a video with a frame rate of 5 frames per second.

To compensate for this exposure limit, the sensor has to increase the sensitivity, which is the ISO setting, to make the final product brighter. Due to how the electricity interacts between sensor pixels, increasing ISO increases the noise in the photo/video. Some noise can be edited out with post processing, but excessive noise can't be edited out without losing a lot of detail in the process. Because the sensors on our phones are tiny, they are more susceptible to ISO noise.

That's why any sort of video function, be it a live preview or a video call, requires more light to look good. Adding more ambient lighting lets the camera turn down the ISO, thus also reducing noise. It also may allow for a faster shutter speed, which will reduce any motion blur.

Btw, I see you're actually a new member. Welcome to the forums, and hopefully this helped.