Hi,

I've been shooting video with my Sony A7III for a couple of years now and generally, the camera has been great, particularly in low light. However, since about 3 weeks ago, I've begun seeing a lot of noise in my footage. I'm shooting 4k 24p and my ISO never exceed 800. Now, before anyone mentions under-exposure and high ISO as the common problems, please hear me out: i AM GETTING NOISE IN LIGHTING SITUATIONS WHERE PREVIOUSLY THE CAMERA WOULD DO JUST FINE. In fact, sometimes, I will start getting noise midway through a shoot, even though the lighting, aperture, iso and shutter speed remain the same. Or conversely, sometimes I'll start shooting a scene and it will be noisy for no reason, and then, half an hour or so later, after turning the camera on and off multiple times during the shoot, I'll suddenly notice that the problem is gone.

What's up with this? Is there anything I can do to fix it? Please let me know because this is becoming a serious problem! Currently, the lenses I am using are Sony 20mm 1.8 G, Sony 50mm 1.8 and Sony 85mm 1.8. Thanks!

To me this sounds like a sensor fault. Get it to Sony for a warranty fault, or if that's not still valid find a trusted Sony repair shop.