How much internal dust in new lenses today is acceptable?

Thanks, I will give them a call.

Hello; I am new to this forum and new to photography. My question is per IR cutting filters for taking pictures of the sun. I understand the need for ND filters, but they do not block the infrared, which makes up about 55% of the light spectrum. UV being about 3%, and visible light about 42%. My two telephoto lenses have a 105mm and 122mm filter thread. What filters should one be using in order to protect the camera sensor? And whom makes filters / kits for telephoto lenses larger than the norm? Thank you. Life is great; Kim.