Sprawa wcale nie jest taka oczywista https://www.cloudynights.com/topic/119164-optics-cleaning-with-ipa/ w szczególności: https://www.cloudynights.com/topic/119164-optics-cleaning-with-ipa/?p=1569036 How to Care for Your Telescope Optics the Right Way https://www.skyandtelescope.com/astronomy-resources/caring-for-your-optics/