RF 50mm F1.2 - Smudges on glass won't go away

[SarVinci]

Hello Canon Community,

I recently noticed micro particles I wanted to remove and couldn't on my Canon RF 50mm F1.2 lens, I found a glass cleaner I realized I shouldn't have used because it had dust on it too. I used 70% alcohol that contains purified water, ALSO I am talking about the back part of the lens glass near the sensor when attached to camera body. There are still some smudges on there I tried removing, no luck 100%. I bought a K&F Concept kit with a spray bottle, is that a good way to clean it? Was there any lens coating damaged I may have caused on the back glass? Is it possible to remove the smudge and smears with a cleaner microfiber cloth and the solution from K&F?

[ebiggs1]

OK, sorry, I thought you were cleaning the front element. Although a very expensive lens like yours will have coating on the rear element all lenses do not have that. In my nearly 6 decades of photography I don't ever remember cleaning the rear element beyond using a Rocket blower.

Here is my advice, if it is not impacting your photos I would ignore it. Leave it alone!  As it most likely doesn't hurt anything. However, if it does and you are concerned about it, you need to send it to Canon for service. You can only make it worse.

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