Multi-coated filter or no?

[willy_boots]

<p>So I'm thinking about my next lens purchase being the CV 40mm Nokton 1.4. I'd like to get the single coated version. Shooting black and white I'll have a medium-yellow filter on most of the time. If this filter is multi-coated then does that make it pointless to use a single-coated lens? What's the deal here?</p>

[craigd]

<p>You want everything multi-coated. Each air-glass interface reflects some amount of light. If it is single-coated it reflects less than if it were not coated at all, and if it's multi-coated it reflects less than it if were single-coated. Less reflection means better contrast and less risk of visible ghost images.</p>

[willy_boots]

<p>@Craig yeah that's what I'm reading. The idea behind the CV single-coated lens is that it gives greater shadow detail for black and white photography. That sounds good, but I'm wondering if the glass I put in front of it will just negate that quality of the lens.</p>

[joseph_wisniewski]

<p>It's easy to think your way through this one.</p>

<ul>

<li>Single coated filters reflect more less light and transmit less light than uncoated filters, so they affect your image less than uncoated filters do.</li>

<li>Multicoated filters reflect less light and transmit more light than single coated filters, so they affect your image less than single coated filters do.</li>

<li>Air reflects less light and transmits more light than multicoated filters do, and air doesn't affect your image, at all.</li>

</ul>

<p>So, if you have a lens with a character that you like, using a multicoated filter in front of it will change that lens's character less than using a single coated filter or an uncoated filter.</p>

[willy_boots]

<p>@Joseph: are you high?</p>

[luis_g]

<p>I think Joseph, whom you have insulted, is correct. Yes to MC filters. But why not waste $10+ and test this for yourself? Used SC filters are cheap. Do the test for yourself.</p>

[akira]

<p>"@Joseph: are you high?"</p>

<p>I bet he was yawning. ;)</p>

[david_henderson]

<p>Multicoated are better. But you would only notice a difference on some photographs. The angle and strength of light hitting the front element sometimes causes flare and/or lost contrast. It will happen less often with a multicoated filter than with a sc filter or an uncoated filter. However you will never be able to look at a perfectly normal shot and say "that would have been wrecked without my multicoating". Nor indeed would you ever be able to say with any certainty after having used a SC filter "that shot has flare; if I'd used a multicoated filter it wouldn't have flare"</p>

<p>In short this is an issue in which you can see failures but not successes. Buying mc filters is to an extent an act of faith, on the basis that you understand and value that over a year a proportion of your photographs ( and that might be a small proportion depending on what/how you photograph) will be better because of that decision even though you can't be sure about which ones. What's more the "improved" photographs might be important to you, or might be inconsequential. Note also that MC does not guarantee no flare/lost contrast- it reduces the chances, thats all. </p>

[hjoseph7]

<p>"Air reflects less light and transmits more light than multicoated filters do, and air doesn't affect your image, at all."</p>

<p>Air is transparent while a filter is translucent. The book Light Science & Magic goes over that subject.</p>

[alex_lofquist]

<p>Except for long distances.</p>