ntonkin Loc: western Upper Peninusla of Michigan

I just bought a Canon 100mm Macro on Ebay and it arrived quite dirty. The glass has no scratches but there are a couple of small spots on the inside of the objective glass. The larger one is about 2mm in size and the other is maybe ½ mm. Does anyone know the best way to clean these spots? I've searched google and can't find anything on disassembly of Canon Lenses.

larrycumba

If it is not affecting the image leave it alone. If you feel adventurous youtube has a few videos that might help.

ShakyShutter Loc: Arizona

It may not be affecting the image at this point at all. If it's dirt/dust it may dislodge and fall to the side. If, however, it's fungus growing, which happens all the time, it may continue to grow and will eventually affect normal images. It needs to be removed by a professional repair shop.

You're not likely to see any effect on photos until the f-stop is at about f-22 or smaller. And even then the light would have to be just right for those spots to have much effect.

ntonkin Loc: western Upper Peninusla of Michigan

Thanks for the advice. I haven't actually used it yet so maybe I'll see how it goes.