I have some old m42 prime lens like Pentacon Multi-Coated f/2.8 135mm, and modern lens Canon EF-S 18-55 mm and Sigma 70-300 mm.
How much is the difference in the multi-coatings of old and modern lens? Some old lens are known for their Bokeh. Can difference in multi-coatings affects the sharpness, Bokeh and anything else? Can it affects the IQ when filters (circular polarizer, UV etc) are used with old lens?
Thank you in advance!