"Scratched" sensor on a 5100

[Phormula]

I had the possibility to get a used 5100 for a ridicolous price.

The reason is that the previous owner did a harsh clean of the sensor and scratched the surface. When he realised, he decided to get rid of it. 

Actually, what got removed, is the surface coating. The glass is still intact.

Before buying it, I tested the camera and saw no effect in pictures, even shutting down to /f 22. Given the fact that I plan to toss it into my bag when on business trip and that if I got it for the price of the kit lens that came attached to it, I decided to buy it anyway. If it gets broken or stolen is not like losing my other Sony and the 5100 is smaller and lighter.

My question is if somebody has experienced a similar situation and had noticed impacts on picture quality and, if so, under which conditions.

 

[Pieter]

The coating is there for many reasons: anti-static, oil resistant, anti-glare/ghosting and apparently it also prevents glass corrosion:

https://kolarivision.com/preventing-glass-corrosion-on-blackmagic-leica-and-other-camera-sensors/?srsltid=AfmBOooLPlNh2nRSJxZgrlAahZGxJuWWzZvQ3p6X2LlnSZSmeQ91oIm6#conversions-and-services

You might not notice much of it at first but likely image quality will degrade over time.

[Phormula]

Thanks Pieter for the exhaustive explanation.

So far, so good. I have been using the camera over the last week with no impact on image quality.

Given your answer, I can expect some issues somewhere in the future. Sensor replacement is out of the question, the cost will be higher than the value of the camera. Given what I paid for it (it came almost for free, I paid the price of a good kit lens and the camera came attached to it), I plan to use it as long as I see some image degradation, and then trash it. I like the compactness and light weight, welcome on business travel. We'll see when it happens. 

[Pieter]

Image quality per camera volume, the A5100 is an outstanding little camera. Just have fun while it lasts 😄

[Phormula]

Exactly, with the kit lens it fits in a coat pocket and it is much, much better than a point and shoot.

It is a pity that it is no longer in production.