[natestation]

I recently purchased a sears auto 55 f1.4 off the bay, but I'm still waiting for it to arrive. In the meantime, I was curious about the way MC filters work when placed on single or non-coated lenses. Will the old lens become roughly as flare resistant as the standard Pentax SMC lens? Or does the non-coated lens under the filter still cause flaring regardless of the filter?

[Adam]

Moved to the accessory section. AFAIK, it still matters what's under the glass, as the light continues to bend after passing through the filter

[MrEspie]

The best case scenario is that it will have no effect (assuming 100% transmission). Every transition surface will affect some amount of reflection. Throwing a filter in front merely adds two more surfaces to lose and/or scatter light. Your best bet with an old, uncoated lens is to use a lens hood and stop down when you can.

[natestation]

That does help. I don't like the answer, but it does help

[bdery]

Indeed, most optical surfaces, uncoated, will reflect around 4% of incoming light. And for the record, a single "lens element" (think of a magnifying lens, for instance, as being a single elenàment) has two surfaces. That's why coatings exist, they improve light transmission for certain wavelengths (colours).

Each lens surface is responsible for part of the total picture degradation the lens creates.