Multi-coat UV/protective filters, Multi-part question

[WDPictures]

Seen similar posts re lens protection: do you/don't you but my question(s)...
1) Is there an advantage to using MC filters if the lens is already MC?
1a) Does the extra MC layer help prevent flare between the filter and lens, worth the extra MC cost?
2) Similarly, is it advantageous to use a MC filter on un-coated or single-coated glass?
3) Say if I wanted lens protection for peace of mind, am I better off buying a decent quality (meaning less chance of thread binding) non-coated filter?

[sfj]

Multiple-layer lens coatings reduce the reflectance of each layer on which they're deposited. Theoretically, every surface of every optical element should be MC. In practice, even single-coated lenses of the 1950s do a good job as long as you are out of direct sunlight.

[wolves3012]

1) Yes a MC filter is theoretically better.

2) Yes but the cost is subjective.

3) Yes, it's still better.

4) No, MC is better but quality still matters.

Overall, you're better off with a MC, all other things being equal. In most situations, however, you're unlikely to see a staggering difference.

[ferider]

Like wolves said. If you use filters, get the best you can get, multi-coated, and easy to clean. In particular on a rare old lens with soft coating.

Biggest problem with cheap/SC filters are ghosts when shooting against strong light sources, as typical in low light.

MC on an SC lens since I assume you want to see the lens, not the filter signature.

My two cents - opinions are strong and vary on this matter :)

Roland.